title: Escape velocity

text: In most situations it is impractical to achieve escape velocity almost instantly, because of the acceleration implied, and also because if there is an atmosphere, the hypersonic speeds involved (on Earth a speed of 11.2 km/s, or 40,320 km/h) would cause most objects to burn up due to aerodynamic heating or be torn apart by atmospheric drag. For an actual escape orbit, a spacecraft will accelerate steadily out of the atmosphere until it reaches the escape velocity appropriate for its altitude (which will be less than on the surface). In many cases, the spacecraft may be first placed in a parking orbit (e.g. a low Earth orbit at 160–2,000 km) and then accelerated to the escape velocity at that altitude, which will be slightly lower (about 11.0 km/s at a low Earth orbit of 200 km). The required additional change in speed, however, is far less because the spacecraft already has a significant orbital speed (in low Earth orbit speed is approximately 7.8 km/s, or 28,080 km/h).


title: Escape velocity

text: The escape velocity at a given height is formula_15 times the speed in a circular orbit at the same height, (compare this with the velocity equation in circular orbit). This corresponds to the fact that the potential energy with respect to infinity of an object in such an orbit is minus two times its kinetic energy, while to escape the sum of potential and kinetic energy needs to be at least zero. The velocity corresponding to the circular orbit is sometimes called the first cosmic velocity, whereas in this context the escape velocity is referred to as the second cosmic velocity.


title: Escape velocity

text: For a body in an elliptical orbit wishing to accelerate to an escape orbit the required speed will vary, and will be greatest at periapsis when the body is closest to the central body. However, the orbital speed of the body will also be at its highest at this point, and the change in velocity required will be at its lowest, as explained by the Oberth effect.


title: Escape velocity

text: Escape velocity can either be measured as relative to the other, central body or relative to center of mass or barycenter of the system of bodies. Thus for systems of two bodies, the term "escape velocity" can be ambiguous, but it is usually intended to mean the barycentric escape velocity of the less massive body. Escape velocity usually refers to the escape velocity of zero mass test particles. For zero mass test particles we have that the 'relative to the other' and the 'barycentric' escape velocities are the same, namely formula_16.


title: Escape velocity

text: Because the system has to obey the law of conservation of momentum we see that both the larger and the smaller mass must be accelerated in the gravitational field. Relative to the center of mass the velocity of the larger mass (formula_18 , for planet) can be expressed in terms of the velocity of the smaller mass (formula_19, for rocket). We get formula_20.


title: Escape velocity

text: The 'barycentric' escape velocity now becomes : formula_21 while the 'relative to the other' escape velocity becomes : formula_22.


title: Escape velocity

text: Ignoring all factors other than the gravitational force between the body and the object, an object projected vertically at speed formula_23 from the surface of a spherical body with escape velocity formula_6 and radius formula_25 will attain a maximum height formula_26 satisfying the equation


title: Escape velocity

text: If an object attains exactly escape velocity, but is not directed straight away from the planet, then it will follow a curved path or trajectory. Although this trajectory does not form a closed shape, it can be referred to as an orbit. Assuming that gravity is the only significant force in the system, this object's speed at any point in the trajectory will be equal to the escape velocity "at that point" due to the conservation of energy, its total energy must always be 0, which implies that it always has escape velocity; see the derivation above. The shape of the trajectory will be a parabola whose focus is located at the center of mass of the planet. An actual escape requires a course with a trajectory that does not intersect with the planet, or its atmosphere, since this would cause the object to crash. When moving away from the source, this path is called an escape orbit. Escape orbits are known as "C3" = 0 orbits. "C3" is the characteristic energy, = −"GM"/2"a", where "a" is the semi-major axis, which is infinite for parabolic trajectories.


title: Escape velocity

text: If the body has a velocity greater than escape velocity then its path will form a hyperbolic trajectory and it will have an excess hyperbolic velocity, equivalent to the extra energy the body has. A relatively small extra delta-"v" above that needed to accelerate to the escape speed can result in a relatively large speed at infinity. Some orbital manoeuvres make use of this fact. For example, at a place where escape speed is 11.2 km/s, the addition of 0.4 km/s yields a hyperbolic excess speed of 3.02 km/s:


title: Escape velocity

text: If a body in circular orbit (or at the periapsis of an elliptical orbit) accelerates along its direction of travel to escape velocity, the point of acceleration will form the periapsis of the escape trajectory. The eventual direction of travel will be at 90 degrees to the direction at the point of acceleration. If the body accelerates to beyond escape velocity the eventual direction of travel will be at a smaller angle, and indicated by one of the asymptotes of the hyperbolic trajectory it is now taking. This means the timing of the acceleration is critical if the intention is to escape in a particular direction.


title: Escape velocity

text: This is valid for elliptical, parabolic, and hyperbolic trajectories. If the trajectory is hyperbolic or parabolic, it will asymptotically approach an angle formula_34 from the direction at periapsis, with


title: Escape velocity

text: In this table, the left-hand half gives the escape velocity from the visible surface (which may be gaseous as with Jupiter for example), relative to the centre of the planet or moon (that is, not relative to its moving surface). In the right-hand half, "V" refers to the speed relative to the central body (for example the sun), whereas "V" is the speed (at the visible surface of the smaller body) relative to the smaller body (planet or moon).


title: Escape velocity

text: The last two columns will depend precisely where in orbit escape velocity is reached, as the orbits are not exactly circular (particularly Mercury and Pluto).


title: Escape velocity

text: Let "G" be the gravitational constant and let "M" be the mass of the earth (or other gravitating body) and "m" be the mass of the escaping body or projectile. At a distance "r" from the centre of gravitation the body feels an attractive force


title: Escape velocity

text: The total work needed to move the body from the surface "r" of the gravitating body to infinity is then


title: Escape velocity

text: In order to do this work to reach infinity, the body's minimal kinetic energy at departure must match this work, so the escape velocity "v" satisfies


title: Curiosity (rover)

text: Curiosity is a car-sized Mars rover designed to explore the Gale crater on Mars as part of NASA's Mars Science Laboratory (MSL) mission. "Curiosity" was launched from Cape Canaveral (CCAFS) on November 26, 2011, at 15:02:00 UTC and landed on Aeolis Palus inside Gale crater on Mars on August 6, 2012, 05:17:57 UTC. The Bradbury Landing site was less than from the center of the rover's touchdown target after a journey.


title: Curiosity (rover)

text: Mission goals include an investigation of the Martian climate and geology, assessment of whether the selected field site inside Gale has ever offered environmental conditions favorable for microbial life (including investigation of the role of water), and planetary habitability studies in preparation for human exploration.


title: Curiosity (rover)

text: In December 2012, "Curiosity" two-year mission was extended indefinitely, and on August 5, 2017, NASA celebrated the fifth anniversary of the "Curiosity" rover landing. On August 6, 2022, a detailed overview of accomplishments by the "Curiosity" rover for the last ten years was reported. The rover is still operational, and as of 28 2022, "Curiosity" has been active on Mars for sols ( total days; "") since its landing (see current status).


title: Curiosity (rover)

text: The NASA/JPL Mars Science Laboratory/"Curiosity" Project Team was awarded the 2012 Robert J. Collier Trophy by the National Aeronautic Association "In recognition of the extraordinary achievements of successfully landing "Curiosity" on Mars, advancing the nation's technological and engineering capabilities, and significantly improving humanity's understanding of ancient Martian habitable environments." "Curiosity" rover design serves as the basis for NASA's 2021 "Perseverance" mission, which carries different scientific instruments.


title: Curiosity (rover)

text: As established by the Mars Exploration Program, the main scientific goals of the MSL mission are to help determine whether Mars could ever have supported life, as well as determining the role of water, and to study the climate and geology of Mars. The mission results will also help prepare for human exploration. To contribute to these goals, MSL has eight main scientific objectives:


title: Curiosity (rover)

text: About one year into the surface mission, and having assessed that ancient Mars could have been hospitable to microbial life, the MSL mission objectives evolved to developing predictive models for the preservation process of organic compounds and biomolecules; a branch of paleontology called taphonomy. The region it is set to explore has been compared to the Four Corners region of the North American west.


title: Curiosity (rover)

text: A NASA panel selected the name "Curiosity" following a nationwide student contest that attracted more than 9,000 proposals via the Internet and mail. A sixth-grade student from Kansas, 12-year-old Clara Ma from Sunflower Elementary School in Lenexa, Kansas, submitted the winning entry. As her prize, Ma won a trip to NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, where she signed her name directly onto the rover as it was being assembled.


title: Curiosity (rover)

text: Adjusted for inflation, "Curiosity" has a life-cycle cost of US$3.2 billion in 2020 dollars. By comparison, the 2021 "Perseverance" rover has a life-cycle cost of US$2.9 billion.


title: Curiosity (rover)

text: "Curiosity" is long by wide by in height, larger than Mars Exploration Rovers, which are long and have a mass of including of scientific instruments. In comparison to Pancam on the Mars Exploration Rovers, the MastCam-34 has 1.25× higher spatial resolution and the MastCam-100 has 3.67× higher spatial resolution.


title: Curiosity (rover)

text: "Curiosity" has an advanced payload of scientific equipment on Mars. It is the fourth NASA robotic rover sent to Mars since 1996. Previous successful Mars rovers are "Sojourner" from the Mars Pathfinder mission (1997), and "Spirit" (2004–2010) and "Opportunity" (2004–2018) rovers from the Mars Exploration Rover mission.


title: Curiosity (rover)

text: "Curiosity" comprised 23% of the mass of the spacecraft at launch. The remaining mass was discarded in the process of transport and landing.


title: Curiosity (rover)

text: "Curiosity" landed in Quad 51 (nicknamed Yellowknife) of Aeolis Palus in the crater Gale. The landing site coordinates are: . The location was named Bradbury Landing on August 22, 2012, in honor of science fiction author Ray Bradbury. Gale, an estimated 3.5 to 3.8 billion-year-old impact crater, is hypothesized to have first been gradually filled in by sediments; first water-deposited, and then wind-deposited, possibly until it was completely covered. Wind erosion then scoured out the sediments, leaving an isolated mountain, Aeolis Mons ("Mount Sharp"), at the center of the wide crater. Thus, it is believed that the rover may have the opportunity to study two billion years of Martian history in the sediments exposed in the mountain. Additionally, its landing site is near an alluvial fan, which is hypothesized to be the result of a flow of ground water, either before the deposition of the eroded sediments or else in relatively recent geologic history.


title: Curiosity (rover)

text: According to NASA, an estimated 20,000 to 40,000 heat-resistant bacterial spores were on "Curiosity" at launch, and as many as 1,000 times that number may not have been counted.


title: Curiosity (rover)

text: Previous NASA Mars rovers became active only after the successful entry, descent and landing on the Martian surface. "Curiosity", on the other hand, was active when it touched down on the surface of Mars, employing the rover suspension system for the final set-down.


title: Curiosity (rover)

text: "Curiosity" transformed from its stowed flight configuration to a landing configuration while the MSL spacecraft simultaneously lowered it beneath the spacecraft descent stage with a tether from the "sky crane" system to a soft landing—wheels down—on the surface of Mars. After the rover touched down it waited 2 seconds to confirm that it was on solid ground then fired several pyrotechnic fasteners activating cable cutters on the bridle to free itself from the spacecraft descent stage. The descent stage then flew away to a crash landing, and the rover prepared itself to begin the science portion of the mission.


title: Curiosity (rover)

text: As of December 9, 2020, the rover was away from its landing site. As of April 17, 2020, the rover has been driven on fewer than 800 of its 2736 sols (Martian days).


title: Curiosity (rover)

text: Curiosity has two full sized, vehicle system test bed (VSTB), a twin rover used for testing and problem solving, MAGGIE rover (Mars Automated Giant Gizmo for Integrated Engineering) with a computer brain and a Scarecrow rover without a computer brain. They are housed at the JPL Mars Yard for problem solving on simulated Mars terrain.


title: Curiosity (rover)

text: The general sample analysis strategy begins with high-resolution cameras to look for features of interest. If a particular surface is of interest, "Curiosity" can vaporize a small portion of it with an infrared laser and examine the resulting spectra signature to query the rock's elemental composition. If that signature is intriguing, the rover uses its long arm to swing over a microscope and an X-ray spectrometer to take a closer look. If the specimen warrants further analysis, "Curiosity" can drill into the boulder and deliver a powdered sample to either the Sample Analysis at Mars (SAM) or the CheMin analytical laboratories inside the rover. The MastCam, Mars Hand Lens Imager (MAHLI), and Mars Descent Imager (MARDI) cameras were developed by Malin Space Science Systems and they all share common design components, such as on-board digital image processing boxes, 1600 × 1200 charge-coupled device (CCDs), and an RGB Bayer pattern filter.


title: Curiosity (rover)

text: In total, the rover carries 17 cameras: HazCams (8), NavCams (4), MastCams (2), MAHLI (1), MARDI (1), and ChemCam (1).


title: Curiosity (rover)

text: The MastCam system provides multiple spectra and true-color imaging with two cameras. The cameras can take true-color images at 1600×1200 pixels and up to 10 frames per second hardware-compressed video at 720p (1280×720).


title: Curiosity (rover)

text: One MastCam camera is the Medium Angle Camera (MAC), which has a focal length, a 15° field of view, and can yield 22 cm/pixel (8.7 in/pixel) scale at . The other camera in the MastCam is the Narrow Angle Camera (NAC), which has a focal length, a 5.1° field of view, and can yield 7.4 cm/pixel (2.9 in/pixel) scale at . Malin also developed a pair of MastCams with zoom lenses, but these were not included in the rover because of the time required to test the new hardware and the looming November 2011 launch date. However, the improved zoom version was selected to be incorporated on the Mars 2020 mission as Mastcam-Z.


title: Curiosity (rover)

text: Each camera has eight gigabytes of flash memory, which is capable of storing over 5,500 raw images, and can apply real time lossless data compression. The cameras have an autofocus capability that allows them to focus on objects from to infinity. In addition to the fixed RGBG Bayer pattern filter, each camera has an eight-position filter wheel. While the Bayer filter reduces visible light throughput, all three colors are mostly transparent at wavelengths longer than 700 nm, and have minimal effect on such infrared observations.


title: Curiosity (rover)

text: ChemCam is a suite of two remote sensing instruments combined as one: a laser-induced breakdown spectroscopy (LIBS) and a Remote Micro Imager (RMI) telescope. The ChemCam instrument suite was developed by the French CESR laboratory and the Los Alamos National Laboratory. The flight model of the mast unit was delivered from the French CNES to Los Alamos National Laboratory. The purpose of the LIBS instrument is to provide elemental compositions of rock and soil, while the RMI gives ChemCam scientists high-resolution images of the sampling areas of the rocks and soil that LIBS targets. The LIBS instrument can target a rock or soil sample up to away, vaporizing a small amount of it with about 50 to 75 5-nanosecond pulses from a 1067 nm infrared laser and then observes the spectrum of the light emitted by the vaporized rock.


title: Curiosity (rover)

text: ChemCam has the ability to record up to 6,144 different wavelengths of ultraviolet, visible, and infrared light. Detection of the ball of luminous plasma is done in the visible, near-UV and near-infrared ranges, between 240 nm and 800 nm. The first initial laser testing of the ChemCam by "Curiosity" on Mars was performed on a rock, N165 ("Coronation" rock), near Bradbury Landing on August 19, 2012. The ChemCam team expects to take approximately one dozen compositional measurements of rocks per day. Using the same collection optics, the RMI provides context images of the LIBS analysis spots. The RMI resolves objects at distance, and has a field of view covering at that distance.


title: Curiosity (rover)

text: The rover has two pairs of black and white navigation cameras mounted on the mast to support ground navigation. The cameras have a 45° angle of view and use visible light to capture stereoscopic 3-D imagery.


title: Curiosity (rover)

text: REMS comprises instruments to measure the Mars environment: humidity, pressure, temperatures, wind speeds, and ultraviolet radiation. It is a meteorological package that includes an ultraviolet sensor provided by the Spanish Ministry of Education and Science. The investigative team is led by Javier Gómez-Elvira of the Spanish Astrobiology Center and includes the Finnish Meteorological Institute as a partner. All sensors are located around three elements: two booms attached to the rover's mast, the Ultraviolet Sensor (UVS) assembly located on the rover top deck, and the Instrument Control Unit (ICU) inside the rover body. REMS provides new clues about the Martian general circulation, micro scale weather systems, local hydrological cycle, destructive potential of UV radiation, and subsurface habitability based on ground-atmosphere interaction.


title: Curiosity (rover)

text: The rover has four pairs of black and white navigation cameras called hazcams, two pairs in the front and two pairs in the back. They are used for autonomous hazard avoidance during rover drives and for safe positioning of the robotic arm on rocks and soils. Each camera in a pair is hardlinked to one of two identical main computers for redundancy; only four out of the eight cameras are in use at any one time. The cameras use visible light to capture stereoscopic three-dimensional (3-D) imagery. The cameras have a 120° field of view and map the terrain at up to in front of the rover. This imagery safeguards against the rover crashing into unexpected obstacles, and works in tandem with software that allows the rover to make its own safety choices.


title: Curiosity (rover)

text: MAHLI is a camera on the rover's robotic arm, and acquires microscopic images of rock and soil. MAHLI can take true-color images at 1600×1200 pixels with a resolution as high as 14.5 µm per pixel. MAHLI has an focal length and a 33.8–38.5° field of view. MAHLI has both white and ultraviolet Light-emitting diode (LED) illumination for imaging in darkness or fluorescence imaging. MAHLI also has mechanical focusing in a range from infinite to millimeter distances. This system can make some images with focus stacking processing. MAHLI can store either the raw images or do real time lossless predictive or JPEG compression. The calibration target for MAHLI includes color references, a metric bar graphic, a 1909 VDB Lincoln penny, and a stair-step pattern for depth calibration.


title: Curiosity (rover)

text: The APXS instrument irradiates samples with alpha particles and maps the spectra of X-rays that are re-emitted for determining the elemental composition of samples. "Curiosity" APXS was developed by the Canadian Space Agency (CSA). MacDonald Dettwiler (MDA), the Canadian aerospace company that built the Canadarm and RADARSAT, were responsible for the engineering design and building of the APXS. The APXS science team includes members from the University of Guelph, the University of New Brunswick, the University of Western Ontario, NASA, the University of California, San Diego and Cornell University. The APXS instrument takes advantage of particle-induced X-ray emission (PIXE) and X-ray fluorescence, previously exploited by the Mars Pathfinder and the two Mars Exploration Rovers.


title: Curiosity (rover)

text: CheMin is the Chemistry and Mineralogy X-ray powder diffraction and fluorescence instrument. CheMin is one of four spectrometers. It can identify and quantify the abundance of the minerals on Mars. It was developed by David Blake at NASA Ames Research Center and the Jet Propulsion Laboratory, and won the 2013 NASA Government Invention of the year award. The rover can drill samples from rocks and the resulting fine powder is poured into the instrument via a sample inlet tube on the top of the vehicle. A beam of X-rays is then directed at the powder and the crystal structure of the minerals deflects it at characteristic angles, allowing scientists to identify the minerals being analyzed.


title: Curiosity (rover)

text: On October 17, 2012, at "Rocknest", the first X-ray diffraction analysis of Martian soil was performed. The results revealed the presence of several minerals, including feldspar, pyroxenes and olivine, and suggested that the Martian soil in the sample was similar to the "weathered basaltic soils" of Hawaiian volcanoes. The paragonetic tephra from a Hawaiian cinder cone has been mined to create Martian regolith simulant for researchers to use since 1998.


title: Curiosity (rover)

text: The SAM instrument suite analyzes organics and gases from both atmospheric and solid samples. It consists of instruments developed by the NASA Goddard Space Flight Center, the Laboratoire Inter-Universitaire des Systèmes Atmosphériques (LISA) (jointly operated by France's CNRS and Parisian universities), and Honeybee Robotics, along with many additional external partners. The three main instruments are a Quadrupole Mass Spectrometer (QMS), a gas chromatograph (GC) and a tunable laser spectrometer (TLS). These instruments perform precision measurements of oxygen and carbon isotope ratios in carbon dioxide (CO) and methane (CH) in the atmosphere of Mars in order to distinguish between their geochemical or biological origin.


title: Curiosity (rover)

text: The Dust Removal Tool (DRT) is a motorized, wire-bristle brush on the turret at the end of "Curiosity" arm. The DRT was first used on a rock target named Ekwir_1 on January 6, 2013. Honeybee Robotics built the DRT.


title: Curiosity (rover)

text: The role of the Radiation assessment detector (RAD) instrument is to characterize the broad spectrum of radiation environment found inside the spacecraft during the cruise phase and while on Mars. These measurements have never been done before from the inside of a spacecraft in interplanetary space. Its primary purpose is to determine the viability and shielding needs for potential human explorers, as well as to characterize the radiation environment on the surface of Mars, which it started doing immediately after MSL landed in August 2012. Funded by the Exploration Systems Mission Directorate at NASA Headquarters and Germany's Space Agency (DLR), RAD was developed by Southwest Research Institute (SwRI) and the extraterrestrial physics group at Christian-Albrechts-Universität zu Kiel, Germany.


title: Curiosity (rover)

text: The DAN instrument employs a neutron source and detector for measuring the quantity and depth of hydrogen or ice and water at or near the Martian surface.


title: Curiosity (rover)

text: The instrument consists of the detector element (DE) and a 14.1 MeV pulsing neutron generator (PNG). The die-away time of neutrons is measured by the DE after each neutron pulse from the PNG.


title: Curiosity (rover)

text: MARDI is fixed to the lower front left corner of the body of "Curiosity". During the descent to the Martian surface, MARDI took color images at 1600×1200 pixels with a 1.3-millisecond exposure time starting at distances of about to near from the ground, at a rate of four frames per second for about two minutes. MARDI has a pixel scale of at to at and has a 90° circular field of view. MARDI has eight gigabytes of internal buffer memory that is capable of storing over 4,000 raw images. MARDI imaging allowed the mapping of surrounding terrain and the location of landing. JunoCam, built for the "Juno" spacecraft, is based on MARDI.


title: Curiosity (rover)

text: The rover has a long robotic arm with a cross-shaped turret holding five devices that can spin through a 350° turning range. The arm makes use of three joints to extend it forward and to stow it again while driving. It has a mass of and its diameter, including the tools mounted on it, is about . It was designed, built, and tested by MDA US Systems, building upon their prior robotic arm work on the Mars Surveyor 2001 Lander, the "Phoenix" lander, and the two Mars Exploration Rovers, "Spirit" and "Opportunity".


title: Curiosity (rover)

text: Two of the five devices are "in-situ" or contact instruments known as the X-ray spectrometer (APXS), and the Mars Hand Lens Imager (MAHLI camera). The remaining three are associated with sample acquisition and sample preparation functions: a percussion drill; a brush; and mechanisms for scooping, sieving, and portioning samples of powdered rock and soil. The diameter of the hole in a rock after drilling is and up to deep. The drill carries two spare bits. The rover's arm and turret system can place the APXS and MAHLI on their respective targets, and also obtain powdered sample from rock interiors, and deliver them to the SAM and CheMin analyzers inside the rover.


title: Curiosity (rover)

text: Since early 2015 the percussive mechanism in the drill that helps chisel into rock has had an intermittent electrical short. On December 1, 2016, the motor inside the drill caused a malfunction that prevented the rover from moving its robotic arm and driving to another location. The fault was isolated to the drill feed brake, and internal debris is suspected of causing the problem. By December 9, 2016, driving and robotic arm operations were cleared to continue, but drilling remained suspended indefinitely. The "Curiosity" team continued to perform diagnostics and testing on the drill mechanism throughout 2017, and resumed drilling operations on May 22, 2018.


title: Curiosity (rover)

text: Live video showing the first footage from the surface of Mars was available at NASA TV, during the late hours of August 6, 2012, PDT, including interviews with the mission team. The NASA website momentarily became unavailable from the overwhelming number of people visiting it, and a 13-minute NASA excerpt of the landings on its YouTube channel was halted an hour after the landing by an automated DMCA takedown notice from Scripps Local News, which prevented access for several hours. Around 1,000 people gathered in New York City's Times Square, to watch NASA's live broadcast of "Curiosity" landing, as footage was being shown on the giant screen. Bobak Ferdowsi, Flight Director for the landing, became an Internet meme and attained Twitter celebrity status, with 45,000 new followers subscribing to his Twitter account, due to his Mohawk hairstyle with yellow stars that he wore during the televised broadcast.


title: Curiosity (rover)

text: On August 13, 2012, U.S. President Barack Obama, calling from aboard Air Force One to congratulate the "Curiosity" team, said, "You guys are examples of American know-how and ingenuity. It's really an amazing accomplishment". (Video (07:20))


title: Curiosity (rover)

text: Scientists at the Getty Conservation Institute in Los Angeles, California, viewed the CheMin instrument aboard "Curiosity" as a potentially valuable means to examine ancient works of art without damaging them. Until recently, only a few instruments were available to determine the composition without cutting out physical samples large enough to potentially damage the artifacts. CheMin directs a beam of X-rays at particles as small as and reads the radiation scattered back to determine the composition of the artifact in minutes. Engineers created a smaller, portable version named the "X-Duetto". Fitting into a few briefcase-sized boxes, it can examine objects on site, while preserving their physical integrity. It is now being used by Getty scientists to analyze a large collection of museum antiques and the Roman ruins of Herculaneum, Italy.


title: Curiosity (rover)

text: Prior to the landing, NASA and Microsoft released "Mars Rover Landing", a free downloadable game on Xbox Live that uses Kinect to capture body motions, which allows users to simulate the landing sequence.


title: Curiosity (rover)

text: NASA gave the general public the opportunity from 2009 until 2011 to submit their names to be sent to Mars. More than 1.2 million people from the international community participated, and their names were etched into silicon using an electron-beam machine used for fabricating micro devices at JPL, and this plaque is now installed on the deck of "Curiosity". In keeping with a 40-year tradition, a plaque with the signatures of President Barack Obama and Vice President Joe Biden was also installed. Elsewhere on the rover is the autograph of Clara Ma, the 12-year-old girl from Kansas who gave "Curiosity" its name in an essay contest, writing in part that "curiosity is the passion that drives us through our everyday lives".


title: Curiosity (rover)

text: On August 6, 2013, "Curiosity" audibly played "Happy Birthday to You" in honor of the one Earth year mark of its Martian landing, the first time for a song to be played on another planet. This was also the first time music was transmitted between two planets.


title: Curiosity (rover)

text: On June 24, 2014, "Curiosity" completed a Martian year — 687 Earth days — after finding that Mars once had environmental conditions favorable for microbial life. "Curiosity" served as the basis for the design of the Perseverance rover for the Mars 2020 rover mission. Some spare parts from the build and ground test of "Curiosity" are being used in the new vehicle, but it will carry a different instrument payload.


title: Curiosity (rover)

text: In 2014, project chief engineer wrote a book detailing the development of the Curiosity rover. "Mars Rover Curiosity: An Inside Account from Curiosity's Chief Engineer, is a first hand account of the development and landing of the Curiosity Rover.


title: Curiosity (rover)

text: On August 5, 2017, NASA celebrated the fifth anniversary of the "Curiosity" rover mission landing, and related exploratory accomplishments, on the planet Mars. (Videos: "Curiosity" First Five Years (02:07); "Curiosity" POV: Five Years Driving (05:49); "Curiosity" Discoveries About Gale Crater (02:54))


title: Curiosity (rover)

text: As reported in 2018, drill samples taken in 2015 uncovered organic molecules of benzene and propane in 3 billion year old rock samples in Gale.


title: Kundali Bhagya

text: Kundali Bhagya () is an Indian Hindi-language romantic drama television series created by Ekta Kapoor. It premiered on 12 July 2017 on Zee TV. A spin-off series of "Kumkum Bhagya", it stars Shraddha Arya, Manit Joura, Ruhi Chaturvedi, Sanjay Gagnani and Shakti Arora.


title: Kundali Bhagya

text: Arora sisters Preeta and Srishti leave their hometown Nasik after the death of their father, Raghuveer Arora, who before dying asked his daughters to go to Mumbai and reunite with their mother, Sarla.


title: Kundali Bhagya

text: Preeta meets the Luthra family and becomes a physiotherapist to their matriarch, Bani Luthra whose younger grandson Karan, a popular cricket star, shares an adversarial relationship with her while the elder grandson Rishabh, a successful business tycoon, shares a rather cordial relationship. The interpersonal relationships develop and grow from this meeting. Karan-Preeta's alliance slowly blossoms into friendship and they gradually fall in love. After a misunderstanding, Karan starts loathing Preeta and marries her out of spite. Though they resolve their differences but their enemies, Sherlyn and Prithvi, keep creating obstacles for the two to keep them apart.


title: Kundali Bhagya

text: Preeta and Karan adopt a child, Pihu. It is later revealed that Karan's college friend and one-sided lover, Sonakshi, made Preeta realise that it is not possible for her to conceive and she gave her pills which will unknowingly stop her from conceiving. Sonakshi hires a goon who creates an accident, in which Pihu dies, and the entire Luthra family members blame Preeta for it and she is thrown out of the house. Preeta leaves for Bangalore with her grandmother.


title: Kundali Bhagya

text: Preeta is back in Mumbai and is working as a physiotherapist at a clinic. She soon learns about what happened in the past two years, where Prithvi captured the Luthras' property and business, and Mahesh is suffering from mental illness. Soon she starts resolving all the problems for the family, and manages to bring Rishabh back, who was stuck in Dubai due to a case planned and plotted against him by Prithvi and Sherlyn. Karan's mind is been poisoned to make him believe that Preeta and Rishabh are having an affair. In a certain turn of events, Natasha and Roxy push a drunk Karan off the dam and he is presumed to be dead. Preeta finds out that she is pregnant with Karan's child. The Luthras perform their custom, Chadar Andazi, where Rishabh marries Preeta.


title: Kundali Bhagya

text: Preeta has given birth to her and Karan's baby, a daughter, Kavya. A mysterious man named Arjun Suryavanshi, who is infact Karan who had a plastic surgery plus a memory loss after his accident, makes an entry into her life to whom she feels drawn to. After remembering everything, Arjun is on a mission to destroy Rishabh and Preeta because he believes that they were the ones to push him off the dam.


title: Kundali Bhagya

text: The production and airing of the show was halted indefinitely in late March 2020 due to the COVID-19 pandemic. Because of the outbreak, the filming of television series and films was halted on 19 March 2020 and expected to resume on 1 April 2020 but could not and the series was last broadcast on 24 March 2020 when the remaining episodes were aired. After three months, the production and filming of the series resumed on 29 June 2020 and broadcast to resume from 13 July 2020.


title: Merv Griffin

text: Mervyn Edward Griffin Jr. (July 6, 1925 – August 12, 2007) was an American television show host and media mogul. He began his career as a radio and big band singer, later appearing in film and on Broadway. From 1965 to 1986 he hosted his own talk show, "The Merv Griffin Show". He also created the game shows "Jeopardy!" and "Wheel of Fortune" through his production companies, Merv Griffin Enterprises and Merv Griffin Entertainment.


title: Merv Griffin

text: Griffin was born July 6, 1925, in San Mateo, California, to Mervyn Edward Griffin Sr., a stockbroker, and Rita Elizabeth Griffin (née Robinson), a homemaker. He had an older sister, Barbara. When he was a child, Griffin used to play Hangman games with his sister during family road trips. It was these games which inspired him to create the game show "Wheel of Fortune" in 1975. The family was Irish American. Raised as a Catholic, Griffin started singing in his church choir as a boy, and by his teens was earning extra money as a church organist. His abilities as a pianist played a part in his early entry into show business.


title: Merv Griffin

text: He attended San Mateo High School, graduating in 1942, and continued to aid in financing the school. He attended San Mateo Junior College and then the University of San Francisco. He was a member of the international fraternity Tau Kappa Epsilon.


title: Merv Griffin

text: During World War II, Griffin was declared 4F after failing several military physical examinations due to a slight heart murmur. During the Korean War several years later, he was examined and deemed healthy enough to serve, but by that time was above age 26 and exempt from the draft.


title: Merv Griffin

text: Griffin started as a singer on radio at age 19, appearing on "San Francisco Sketchbook", a nationally syndicated program based at KFRC. He was overweight as an adolescent and a young man, which disappointed some radio fans when they saw him in person. He wrote years later in his autobiography that there was a deliberate effort to keep the public from finding out how he looked. He resolved to change his appearance, and lost 80 pounds in four months.


title: Merv Griffin

text: Freddy Martin heard him on the radio show and asked him to tour with his orchestra, which he did for four years.


title: Merv Griffin

text: By 1945, Griffin had earned enough money to form his own record label, Panda Records, which produced "Songs by Merv Griffin", the first U.S. album ever recorded on magnetic tape. In 1947, he had a 15-minute Monday-to-Friday singing program on KFRC in San Francisco.


title: Merv Griffin

text: He became increasingly popular with nightclub audiences, and his fame soared among the general public with his 1950 hit "I've Got a Lovely Bunch of Coconuts". The song reached the #1 spot on the Hit Parade and sold three million copies.


title: Merv Griffin

text: At one of his nightclub performances, Griffin was discovered by Doris Day. Day arranged for a screen test at the Warner Bros. Studios for a role in "By the Light of the Silvery Moon" (1953). Griffin did not get the part, but the screen test led to supporting roles in other musical films such as "So This Is Love" (also 1953), which caused a minor controversy when Griffin shared an open-mouthed kiss with Kathryn Grayson. The kiss was a first in Hollywood film history since the introduction of the Production Code in 1934. He also had an uncredited role as a radio announcer in the horror/science fiction film "The Beast from 20,000 Fathoms" (1953).


title: Merv Griffin

text: Griffin also appeared in "The Boy from Oklahoma" and "Phantom of the Rue Morgue" (both 1954), but became disillusioned with movie-making. He bought his contract back from Warner Bros. and decided to devote his attention to a new medium: television.


title: Merv Griffin

text: In 1954, Griffin appeared in several Cinécraft Productions sponsored films including a musical, "Milestones of Motoring" with Joe E. Brown and Rita Farrell.


title: Merv Griffin

text: He decided to spend the summer of 1954 in New York City. He landed a job as the host of a new television show, CBS-TV's "Summer Holiday," a summer replacement for Jane Froman's "U.S.A. Canteen" and Jo Stafford's "The Jo Stafford Show", which he co-hosted with Betty Ann Grove. Griffin and Grove were brought together by Byron Paul, producer of "U.S.A. Canteen", and Irving Mansfield, "Summer Holiday"'s creator. The new show featured live music with two singers while simulating a trip to various places in the world. Mansfield had remembered Griffin from his singing in the Grace Moore picture "So This Is Love", and for his hit song "I've Got a Lovely Bunch of Coconuts." Paul had already signed Grove for the show and was looking for a male co-host. It ran for one summer.


title: Merv Griffin

text: That summer, Griffin became acquainted with music publisher Loring Buzzell. Griffin needed a place to stay and wound up moving in with Buzzell as his new roommate. They had much in common and became instant friends, and Buzzell introduced Griffin to all of New York City's popular musicians and music executives. Buzzell was engaged to popular singer Lu Ann Simms, with a wedding date set for July 24, 1954. Griffin later claimed in interviews that he was best man at their wedding, but was in fact one of the four ushers. After the wedding, and about two months after arriving in the city, Griffin moved into a different apartment, but in the same building, and remained lifelong friends with Buzzell and Simms. When they had their first child, Cynthia Leigh Buzzell, on September 11, 1955, Griffin was named her godfather. Buzzell died of a heart attack in 1959, but Griffin stayed close to Simms for the rest of her life and had her as a guest on his talk show many times.


title: Merv Griffin

text: From 1958 to 1962, Griffin hosted "Play Your Hunch," a game show produced by Mark Goodson and Bill Todman. It ran on all three networks, but primarily NBC. He also hosted a primetime ABC game show, "Keep Talking". He also filled in for a week for the vacationing Bill Cullen on "The Price Is Right", and for Bud Collyer on "To Tell the Truth". In 1963, NBC offered him the opportunity to host a new game show, "Word for Word", which Griffin produced. He also produced "Let's Play Post Office" for NBC in 1965, "Reach for the Stars" for NBC in 1967, and "One in a Million" for ABC in 1967.


title: Merv Griffin

text: Griffin scored a coup when "Tonight Show" host Jack Paar accidentally emerged onto the set of "Play Your Hunch" during a live broadcast, and Griffin got him to stay for a spontaneous interview. Both programs shared Studio 6B at NBC's Rockefeller Center complex at the time, with "Play Your Hunch" airing live in the morning while "Tonight" taped later in the day. After Paar left "The Tonight Show", but before Johnny Carson took over (Carson was still hosting "Who Do You Trust?" for ABC), Griffin was one of the many guest hosts who presided over "Tonight" in the interim. Griffin was considered the most successful of the guest hosts, and was rewarded with his own daytime talk show on NBC in 1962. The live 55-minute program was not successful, however, and was cancelled in 1963.


title: Merv Griffin

text: In 1965, Griffin launched a syndicated talk show for Group W (Westinghouse Broadcasting) titled "The Merv Griffin Show". It aired in a variety of time slots throughout North America; many stations ran it in the daytime, others aired it in primetime, and a few broadcast it opposite Johnny Carson's "The Tonight Show". Griffin's announcer/sidekick was veteran British character actor Arthur Treacher, who had been his mentor. When Treacher left the show in 1970, Griffin did the announcing himself, and walked on stage with the phrase "And now... here I come!" According to an obituary on August 24, 2007 in "Entertainment Weekly", "The Merv Griffin Show" ran for 21 years and won eleven Emmy Awards.


title: Merv Griffin

text: Griffin was not shy about tackling controversial subjects, especially the Vietnam War. The guests on the Westinghouse show were an eclectic mix of entertainers, authors, politicians, and "personality" performers like Zsa Zsa Gabor. Griffin also booked controversial guests like George Carlin, Dick Gregory, Richard Pryor, Norman Mailer and Bertrand Russell. He was commended for booking such guests, but also widely criticized for it. When philosopher and anti-war activist Bertrand Russell used the show to condemn the war in Vietnam, Griffin was criticized for letting Russell have his say. Arnold Schwarzenegger, later 38th governor of California, made his U.S. talk show debut on Griffin's show in 1974 after emigrating from Austria.


title: Merv Griffin

text: Griffin dedicated two shows, in 1975 and 1977, to Transcendental Meditation and its founder Maharishi Mahesh Yogi. The second show aired as a standalone special in some regions such as Canada. Griffin himself was an enthusiastic meditator.


title: Merv Griffin

text: Griffin frequently chatted with audience members. One regular attendee, Lillian Miller, became a fixture on the show throughout its run.


title: Merv Griffin

text: Robert (Bob) Murphy, Griffin's best friend since sixth grade, was the producer of "The Merv Griffin Show," and eventually became president of Merv Griffin Enterprises.


title: Merv Griffin

text: CBS gave Griffin a late-night show opposite Carson in 1969. Griffin's three-year run at CBS was contentious; the network was uncomfortable with the guests he wanted, who often spoke out against the Vietnam War and on other sensitive topics. When political activist Abbie Hoffman was his guest in April 1970, CBS blurred the video of Hoffman so viewers at home would not see his trademark American flag pattern shirt, even though other guests had worn the same shirt in the past, uncensored. Griffin disliked the censorship imposed by CBS and complained.


title: Merv Griffin

text: Sensing that his time at CBS was ending, and tired of the network's restrictions, Griffin secretly signed a contract with rival company Metromedia that gave him a syndicated daytime talk show deal as soon as CBS canceled their show. When he was fired a few months later, his new show began the following Monday, and ran until the mid-1980s. By 1986, Griffin was ready to retire. Profits from his highly successful game shows made him one of the world's wealthiest entertainers.


title: Merv Griffin

text: Griffin created and produced the successful television game show "Jeopardy!" in 1964. In an Associated Press profile released before it premiered, he discussed the show's origins:


title: Merv Griffin

text: The show, originally titled "What's the Question?", premiered on NBC on March 30, 1964, hosted by Art Fleming, and ran for 11 years. Griffin wrote the 30-second piece of music heard during the show's Final Jeopardy! Round, which became the iconic melody of the theme for the syndicated version of the show hosted by Alex Trebek in 1984.


title: Merv Griffin

text: In 1975, NBC canceled "Jeopardy!" after moving it twice on its daytime schedule, despite having an additional year on its network contract. Griffin produced the show's successor, "Wheel of Fortune", which premiered January 6, 1975 with host Chuck Woolery and hostess Susan Stafford, and had high ratings throughout its network run. From December 1975 to January 1976, it was expanded to an hour, in response to the successful 60-minute version of "The Price Is Right" on CBS.


title: Merv Griffin

text: "Wheel" barely escaped cancellation in 1980, when NBC replaced three of its other game shows with a daytime talk show starring David Letterman. NBC finally cancelled it in 1989, when CBS picked it up for a year (only to return to NBC, when the daytime version was finally cancelled for good in 1991). The show became a phenomenon when, on September 19, 1983, a nighttime version hit the syndication market with Pat Sajak and Vanna White as host and hostess. Around that time, Griffin composed the show's best-known theme song, "Changing Keys", which was used in several variants of the show until 2000. The theme returned to the show in 2021 at the start of season 39.


title: Merv Griffin

text: Two revivals of "Jeopardy!" were produced: one on NBC that ran for five months in late 1978/early 1979, with Art Fleming returning as host; and the other airing in first-run syndication beginning September 10, 1984, starring Alex Trebek. The syndicated versions of both "Jeopardy!" and "Wheel" remain on the air today.


title: Merv Griffin

text: In 1990, Griffin had an ambitious but unsuccessful attempt at adapting the venerable board game "Monopoly" into a game show of the same name. His last game show was a wild show called "Ruckus," which emanated from the Resorts International Hotel & Casino in Atlantic City, which he owned at the time. Involving slapstick stunts and a somewhat truncated version of his old "Reach for the Stars," it initially aired locally in New York, with the intent of national syndication early the following year. The Amazing Johnathan left the show after 65 episodes because of a contract dispute, and it was scrapped before it was nationally syndicated. National audiences eventually got a look at it via reruns that aired on GSN.


title: Merv Griffin

text: On his retirement, Griffin sold his production company, Merv Griffin Enterprises, to Columbia Pictures Television—then a unit of The Coca-Cola Company—for US$250 million on May 6, 1986. At the time, it was the largest sale of an entertainment company owned by a single individual, and "Forbes" pronounced Griffin history's richest Hollywood performer. He retained the title of creator of both his game shows.


title: Merv Griffin

text: The two powerhouses spun off numerous programs, for which Griffin often signed on as a creative consultant. The spin-offs included the children's shows "Wheel 2000" (CBS, 1997), and the short-lived "Jep!" (GSN, 1998, both for children); "Rock & Roll Jeopardy!" (VH1, 1998) for pop-music trivia fans; "Click!", a teen-oriented game that introduced Ryan Seacrest as its host; and, in association with Wink Martindale, "Headline Chasers" (1985).


title: Merv Griffin

text: On May 14, 2003, Griffin was honored with the Broadcast Music, Inc. (BMI) President's Award at its annual Film and Television Awards ceremony, for creating some of America's best-known game show melodies.


title: Merv Griffin

text: In 2007, Griffin's production company, Merv Griffin Entertainment, began production on a new syndicated game show, "Merv Griffin's Crosswords" (originally titled "Let's Play Crosswords" and "Let's Do Crosswords"). It taped in Los Angeles after initial reports that it would be produced at WMAQ-TV in Chicago. Produced in association with Program Partners and the William Morris Agency, it began airing September 10, 2007. NBC-owned and -operated stations in New York, Los Angeles, Chicago, San Francisco and Dallas carried it, with many stations airing two episodes per day. It lasted only one season, with its last episode on May 16, 2008, but has had reruns on various channels.


title: Merv Griffin

text: In 1988, he purchased Resorts International and two of their hotels, one in Atlantic City, New Jersey; and another on Paradise Island in the Bahamas, from Donald Trump and other investors. Part of the deal was that Trump would buy Resorts' interest in the yet-to-be-constructed Taj Mahal project for $273 million, and that Trump would own Resorts International Air, which included three Sikorsky S-61 helicopters. In early 1988, Trump wanted to take Resorts private; but Griffin, through Griffin Gaming & Entertainment, offered the minority shareholders significantly more than Trump in April 1988. After Trump paid $101 million for Resorts International Inc. in 1987, Griffin bought it back from him for $365 million and assumed the hotel-casino's debt of $925 million on November 15, 1988. After ten months of ownership, Griffin reported a loss of $46.6 million. He had used $325 million in junk bond financing at nearly 14% from Drexel Burnham Lambert's Michael Milken, but suspended interest payments in early 1989. Cashflow was about $70 million short of what was needed to service the Resorts' debt in 1989, and Griffin sought bankruptcy court protection for Resorts on December 23, 1989.


title: Merv Griffin

text: The background to this was on November 12, when Resorts reached a tentative agreement with certain bondholders, several bondholders petitioned the United States Bankruptcy Court in Camden, New Jersey, to put the company into involuntary bankruptcy to protect legal claims they might have against Trump, the real estate investor Griffin outbid for Resorts the prior year. As a result, this literally wiped out or greatly reduced the investments of the bondholders, so that Mr. Griffin could sue Trump and yet still retain a significant portion for himself.


title: Merv Griffin

text: Besides Resorts International, the holding company for casinos in Atlantic City and the Bahamas, three company affiliates also filed for Chapter 11 protection: Griffin Resorts Inc., Resorts International Financing Inc. and Griffin Resorts Holding Inc.


title: Merv Griffin

text: An active desert resident, Griffin was a supporter of the La Quinta Arts Festival and the owner of the Merv Griffin Givenchy Resort & Spa in Palm Springs, now The Parker. He owned a ranch near La Quinta, California where he raised thoroughbred racehorses, and St. Clerans Manor, a boutique hotel in an eighteenth-century estate once owned by director John Huston, near Craughwell, in County Galway, Ireland. In the 1980s, Griffin purchased the Paradise Island Resort and Casino in the Bahamas for $400 million from Trump, but later sold it for just $125 million. Griffin sold his empire to The Coca-Cola Company for $250 million in 1986, then went on a buying spree of hotels, so that his wealth in 2003 was said to be around $1.2 billion.


title: Merv Griffin

text: Griffin was married to the former Julann Wright from 1958 to 1976; they remained friends after their divorce. They had one son, Tony Griffin, born in 1959; who had two children of his own. In an interview with "The New York Times" published on May 26, 2005, Griffin recalled a quip he frequently used when asked about his private life: "I tell everybody that I'm a quarter-sexual. I will do anything with anybody for a quarter." He was otherwise secretive about his business and personal lives.


title: Merv Griffin

text: In 1991, Deney Terrio, host of the Griffin-created "Dance Fever", sued Griffin, alleging sexual harassment, but the suit was dismissed. That year, Brent Plott, a longtime employee who worked as a bodyguard, horse trainer and driver, filed a $200 million palimony lawsuit, which was also dismissed. Griffin characterized both lawsuits as extortion. His "Los Angeles Times" obituary repeated a 1991 statement he had made regarding Plott's lawsuit: "This is a shameless attempt to extort money from me. This former bodyguard and horse trainer was paid $250 a week, lived in one of two apartments underneath my former house as part of his security function, and left my payroll six or seven years ago. His charges are ridiculous and untrue."


title: Merv Griffin

text: Griffin was a constant companion of actress Eva Gabor from the mid-1980s until her death in 1995, though she told the press in 1990 that they had never been lovers.


title: Merv Griffin

text: After Griffin's death, "The Hollywood Reporter" published a report stating that he had been a closeted gay man. The article was later altered due to protests from his friends and business associates.


title: Merv Griffin

text: On being wealthy, Griffin said, "when you walk down the street and everybody knows you're rich, they don't talk to you." He kept his wealth an open secret, amassing media outlets, hotels and casinos with a net worth estimated at more than $1 billion. He said that he did not know his actual worth because it "would keep me from sleeping at night".


title: Merv Griffin

text: Griffin and First Lady Nancy Reagan exchanged birthday greetings each July 6 for their shared birthday. This continued after her two terms as First Lady. Griffin was also an honorary pallbearer at the funeral of President Ronald Reagan in 2004, having been the Reagans' friends for many years. He was a longtime member of the Republican Party.


title: Merv Griffin

text: In 1974, Griffin was inducted to the Hollywood Walk of Fame. In 1998, a Golden Palm Star on the Walk of Stars in Palm Springs was dedicated to him. In 2005 he accepted the degree of Doctor of Laws (honoris causa) from the National University of Ireland, Galway; and in 2008 was posthumously inducted into the Television Hall of Fame.


title: Merv Griffin

text: Griffin's prostate cancer, treated originally in 1996, returned and he was admitted to Cedars Sinai Medical Center in Los Angeles, where his condition deteriorated, leading to his death on August 12, 2007 at the age of 82.


title: Merv Griffin

text: Funeral services were held on August 17, 2007 at the Church of the Good Shepherd in Beverly Hills. The well-attended service included Nancy Reagan; Arnold Schwarzenegger, who gave the eulogy with Tony Griffin; Maria Shriver; and various actors, television stars, employees, and friends, including Pat Sajak, Vanna White, Alex Trebek, Dick Van Dyke, Jack Klugman, Dick Van Patten, Ellen DeGeneres, Portia de Rossi, Ryan Seacrest, Johnny Mathis, Catherine Oxenberg and Casper Van Dien. Pallbearers included Griffin Group vice-chairman Ron Ward, President Robert Pritchard, and Vice President Michael Eyre, as well as Tony Griffin. His 7-year-old grandson Donovan Mervyn was an honorary pallbearer, as was Nancy Reagan. His 12-year-old granddaughter Farah gave a reading. A post-burial reception was held at the Beverly Hilton, owned by Griffin from 1987 to 2003. He was buried in Westwood Village Memorial Park Cemetery, where his epitaph reads "I will not be right back after this message". (He revealed the epitaph on "The Late Late Show with Tom Snyder". In his book "Merv", written with David Bender in 2003, he stated that it would be "Stay Tuned".)


title: Merv Griffin

text: GSN honored Griffin by airing ten-episode marathons of "Wheel" and "Jeopardy!" during the weekend of August 18–19, 2007. The "Wheel" marathon included two episodes with cameo appearances by Griffin: Sajak's departure from the daytime version in 1989 and a 1992–93 episode that ended with Griffin, his band "The MervTones," and White singing at a dinner club in Orlando, Florida. The "Jeopardy!" marathon consisted of a rerun of the Jeopardy! Million Dollar Masters Tournament from 2002.


title: Respect (2021 American film)

text: Respect is a 2021 American biographical musical drama film directed by Liesl Tommy (in her feature directorial debut), written by Tracey Scott Wilson, Callie Khouri, and is based on the life of American singer Aretha Franklin. The film stars Jennifer Hudson as Franklin, with Forest Whitaker, Marlon Wayans, Audra McDonald, Marc Maron, Tituss Burgess, and Mary J. Blige in supporting roles. The film follows the first three decades of Franklin's life, from being born as a musical prodigy in an affluent African-American family, the repercussions of losing her mother at age 10 to her arduous rise to international musical stardom, while enduring an abusive marriage, ultimately concluding with the recording of her influential live album "Amazing Grace" (1972).


title: Respect (2021 American film)

text: A film on Franklin's life was in development for a long time with Franklin herself involved in the pre-production, however the film languished in development hell for years due to lack of finding a suitable candidate. Following release of the musical film "Dreamgirls" (2006), Franklin asked Hudson to play her but did not finalize her decision until seeing her in the Broadway musical "The Color Purple". The film began production in early 2019 and had concluded by February 2020. The film is dedicated to Franklin, who died in 2018.


title: Respect (2021 American film)

text: After much delay and postponement, due to the burgeoning COVID-19 pandemic, "Respect" premiered in Los Angeles on August 8, 2021, and was released theatrically in the United States on August 13, 2021, by United Artists Releasing, and in other territories by Universal Pictures. The film received generally positive reviews from critics, with praise for the performances, the film's production values, and costume design, but received criticism for its screenplay and runtime.


title: Respect (2021 American film)

text: In 1952, 10-year-old Aretha Franklin lives with her father C.L., pastor of Detroit’s largest Baptist church, and her siblings Cecil, Erma, and Carolyn. Aretha’s father often has her sing for parties at their home, while her mother Barbara, separated from C.L., encourages her independence. The predatory actions of a family friend, combined with the sudden death of Barbara, traumatizes Aretha, who ceases to speak for weeks until her father demands that she sing at church.


title: Respect (2021 American film)

text: Seven years later, Aretha is a teen mother of two boys, but refuses to name their father. Touring as a gospel singer with family friend Dr. Martin Luther King, Jr., she meets local producer Ted White, but C.L. warns him to stay away. C.L. surprises Aretha with a meeting with Columbia Records executive John Hammond. She accepts a contract to record jazz standards, including "Ac-Cent-Tchu-Ate the Positive."


title: Respect (2021 American film)

text: Four albums later, Aretha lacks a signature hit. At a club, she attempts to honor family friend Dinah Washington by performing one of Dinah’s songs; outraged, Dinah advises Aretha to find songs that move her. Struggling with the controlling influence of her father, Aretha begins a relationship with Ted. She brings him home to meet her family, leading C.L. to nearly shoot him, but announces Ted as her manager.


title: Respect (2021 American film)

text: Two years later, Ted and Aretha are married with a child. After nine albums with no real success, Aretha is dropped by Columbia. Ted secures a deal with veteran producer Jerry Wexler of Atlantic Records, who introduces her to a group of white musicians in Muscle Shoals in 1967. There, Aretha records "I Never Loved A Man (The Way I Love You)", but a jealous Ted becomes violent with her.


title: Respect (2021 American film)

text: Returning to Detroit with a black eye, Aretha reconnects with her family. Realizing her song has been released, becoming her first hit, Aretha takes a more hands-on role in her career. She makes her sisters her new backup singers and, despite their misgivings, reunites with Ted. Aretha and Carolyn are inspired to re-arrange Otis Redding's "Respect"; their version becomes a #1 single, launching Aretha to stardom by her 25th birthday.


title: Respect (2021 American film)

text: At a Detroit concert, Dr. King honors Aretha for her support of the Civil Rights Movement, proclaiming February 16 "Aretha Franklin Day". She has another signature hit, "(You Make Me Feel Like) A Natural Woman", but her career is complicated by Ted’s increasingly volatile behavior. Embarking on a European tour in 1968, Aretha is confronted with a "Time" magazine cover story about Ted’s abuse, and finally casts him out of her life.


title: Respect (2021 American film)

text: Dating her tour manager Ken Cunningham, Aretha eventually has her fourth child. In the wake of Dr. King's assassination, Aretha's father drunkenly argues with her over the direction of the Movement, telling her that she no longer walks in the spirit. Aretha continues to release hits but overworks herself, coping with the pressure through alcohol, and rejects her family’s attempts to help her.


title: Respect (2021 American film)

text: During another overseas performance, a drunken Aretha falls from the stage. On a downward spiral and estranged from Ken and her family, she is consoled by a vision of her late mother. Aretha finds the strength to quit drinking, leading Ken to reconcile with her, and returns to her gospel roots. She approaches Wexler with the idea to produce her own gospel album, and he agrees on the condition that the recording of the album be filmed for a documentary.


title: Respect (2021 American film)

text: Beginning rehearsals, Aretha confides in family friend James Cleveland, now a respected gospel artist. The day of the album’s recording, her father arrives to reconcile with her. The service begins and, with her family in attendance, Aretha sings her arrangement of the hymn, "Amazing Grace." An epilogue reveals Aretha Franklin’s legacy as a world-famous artist and the “Queen of Soul”.


title: Respect (2021 American film)

text: The project had been long in development, with Jennifer Hudson set to play Aretha Franklin. Franklin herself was involved with the development up until her death on August 16, 2018. She stated that Hudson would win an Oscar for the portrayal. In January 2019, Liesl Tommy was set to direct the film. The rest of the cast was added in October 2019, including Forest Whitaker, Marlon Wayans, Audra McDonald and Mary J. Blige.


title: Respect (2021 American film)

text: In a June 2019 slate deal, MGM added Bron Creative as a co-financing and producing company to this film. Filming began in Atlanta, Georgia, on September 2, 2019, and wrapped on February 15, 2020. Jonathan Glickman, MGM's President of the Motion Picture Group, exited the company on February 1, 2020, with a first-look deal starting with the film.


title: Respect (2021 American film)

text: The film's soundtrack features one original song, "Here I Am (Singing My Way Home)", performed by Hudson. Written by Hudson, Carole King, and Jamie Hartman and produced by will.i.am and Johnny Goldstein, the song was released on June 18, 2021. "Here I Am (Singing My Way Home)" peaked at number 21 on the "Billboard" Adult R&B Songs chart dated August 28, 2021. The soundtrack album was released on August 13 via Epic Records.


title: Respect (2021 American film)

text: "Respect" premiered in Los Angeles on August 8, 2021, and was theatrically released in the United States on August 13, 2021. It was originally scheduled for a limited release on December 25, 2020, followed by an expansion on January 8, 2021, before going wide the following week. Due to the COVID-19 pandemic, it was switched to a sole wide release on January 15, without a limited release, before it was delayed again to August 2021. Previous release dates also included August 14, 2020, and October 9.


title: Respect (2021 American film)

text: The film screened at the 74th Locarno Film Festival, in the Piazza Grande section to be held from August 4 to 14.


title: Respect (2021 American film)

text: The film was released digitally on August 27, 2021 and on Blu-ray and DVD by Universal Pictures Home Entertainment on November 9, 2021.


title: Respect (2021 American film)

text: "Respect" grossed $24.3 million in the United States and Canada, and $8.7 million in other territories, for a worldwide total of $33 million.


title: Respect (2021 American film)

text: In the United States and Canada, "Respect" was released alongside "Free Guy" and "Don't Breathe 2", and was projected to gross around $10 million from 3,207 theaters in its opening weekend. The film made $3.6 million on its first day, including $650,000 from Thursday night previews. It went on to debut to $8.8 million, finishing fourth at the box office. Despite the film's targeted demographics of older, female, and African-American audiences all being among the most-reluctant to attend a theater amid the pandemic, the film's opening weekend audience was 63% female and 47% African American, with 86% being over the age of 25. The film made $3.8 million in its second weekend (a drop of 57%), finishing fifth, then made $2.2 million in its third weekend.


title: Respect (2021 American film)

text: Outside the U.S., the film's largest opening was in Australia, grossing nearly $1 million in its first weekend. It finished third in the U.K. with $500,000, and debuted to $450,000 in France.


title: Respect (2021 American film)

text: On Rotten Tomatoes, the film holds an approval rating of based on reviews, with an average rating of . The website's critics consensus reads: "This standard-issue biopic falls shy of its subject's transcendent brilliance, but Jennifer Hudson's starring performance absolutely commands "Respect"." On Metacritic, the film has an aggregate score of 61 out of 100 based on 43 critics, indicating "generally favorable reviews". Audiences polled by CinemaScore gave the film an average grade of "A" on an A+ to F scale, while PostTrak reported filmgoers gave it an 89% positive score.


title: Respect (2021 American film)

text: In a positive review from "The New York Times", Manohla Dargis stated that the film "finds its own groove" and praised the performances of Mary J. Blige and Jennifer Hudson." Odie Henderson of "RogerEbert.com" gave the film a score of 3 out of 4 stars, writing that "Hudson performs with the same tireless intensity Re was known for throughout her career. It's a damn entertaining movie." Henderson also said "There's a fair amount of ugliness in Franklin's story—sexual assault, domestic abuse, alcoholism—and it's to the film's credit that it resists the temptation to treat these issues salaciously. But "Respect" never goes deeper than a surface-level exploration of how these traumas affected Franklin."


title: Respect (2021 American film)

text: Writing for "Variety", Peter Debruge called the film an "overly respectful biopic [that] steers clear of revealing the traumas that shaped the soul legend" and said: "Though "Respect" can feel a little soft in the drama department, it delivers the added pleasure of hearing Hudson re-create Franklin's key songs, from the early jazz standards she covered for Columbia to her reinvention of the Otis Redding single that lends the film its name." Also writing for "Variety", Cassie Da Costa praised Hudson's portrayal of Franklin, saying: "Bringing an incredible mix of gestural subtlety and musical power, it cannot be said enough what Hudson achieves here by transmitting a rich sense of interiority, staying true to who Franklin was in private with every look given, word spoken, and melisma sung."


title: Respect (2021 American film)

text: Pete Hammond of "Deadline" also praised Hudson's performance, saying; "This is Jennifer Hudson's triumph merged with the spirit and guidance from an even greater voice above. Hudson's performance is an electrifying sight to behold." Sasha Stone from "Awards Daily", praised the film and especially Hudson's performance, saying: "Hudson's performance is partly her incredible voice. She suspends time in reverie whenever she sings. But this performance also establishes her as an actress capable of navigating the ever-changing waters of Franklin's complicated life—from a young wife who doesn't quite understand exactly what kind of gift she actually has, through to finding a way to honor her own creative spirit." Writing for "Time", Stephanie Zacharek called "Respect" "both entertaining and emotionally revelatory" and praised the performances of the cast, especially Hudson's, saying: "It's Hudson's job to play the adult version of that girl, and she shoulders it with something like tenderness. The easy thing, when you're playing a strong, potent character, is to bite down; Hudson never does. This is a terrific performance, underplayed in all the right ways, an emotionally detailed portrait of a woman who knew what she wanted and knew she could deliver—but who also moved through life knowing that she'd been cruelly robbed of that thing we so sentimentally call childhood."


title: Jordan Knight

text: Jordan Nathaniel Marcel Knight (born May 17, 1970) is an American singer-songwriter and actor. He is a singer in the boy band New Kids on the Block (NKOTB), who rose to fame in the 1980s and 1990s, using a falsetto style of singing influenced by The Stylistics. After New Kids on the Block split in 1994, he launched a solo career. Knight's first solo album, released in 1999, and his latest solo album, released in 2011, reached the Top 50 on the U.S. "Billboard" 200. As of 2011, he released four Top 40 singles; the best known being "Give It to You" in 1999. Knight has released three solo albums, one remix album and one EP. On May 31, 2011, Knight released the studio album, "Unfinished". Knight has sold over 1.5 million records worldwide as a solo artist. In 2015, Boston City Council declared February 7 "Jordan Knight Day".


title: Jordan Knight

text: Jordan Nathaniel Marcel Knight was born in Worcester, Massachusetts, but holds American and Canadian citizenship. His parents are Canadian, his father is from Meaford, Ontario and his mother is from Dunnville, Ontario. He is the youngest of 6 children: Allison, Sharon, David, Christopher, and Jonathan. His father is an Episcopal priest.


title: Jordan Knight

text: Before fame, he played in a youth baseball league in Dorchester, Massachusetts. He was often called out by his teammates for his lack of athleticism, and was told he "throws like a girl". Knight dealt with bullying throughout his childhood and during his early teen years.


title: Jordan Knight

text: Jordan was almost 14 years old in 1984 when he joined New Kids on the Block, a band assembled in Boston by producer Maurice Starr. His fellow members included his brother Jonathan Knight, as well as Joey McIntyre, Donnie Wahlberg, and Danny Wood. Over the next few years, he began writing songs and teaching himself piano and keyboard instruments. Starr, who wrote much of the New Kids material, was reluctant to add his work to the band's repertoire.


title: Jordan Knight

text: New Kids on the Block have sold over 80 million records worldwide, generated hundreds of million of dollars in concert revenues and paved the way for later boy bands like Backstreet Boys and *NSYNC. New Kids on the Block disbanded in 1994, but reunited in 2008.


title: Jordan Knight

text: Knight made a comeback in 1999 by releasing his first solo single, "Give It To You". The single reached No. 10 on the "Billboard" Hot 100, went gold, and was nominated for the 1999 MTV Video Music Award for Best Dance Video, though it lost to Ricky Martin's "Livin' La Vida Loca". He was also nominated for "Favorite Male Singer" at the 2000 Kids' Choice Awards. The single also peaked at No. 35 on the Hot Dance Music/Club Play chart. The album "Jordan Knight" won an Aspire Music Award for Best Male Album (Pop). Knight's self-titled debut album was then certified gold for sales of over 500,000 copies in the US on July 7, 1999. The album peaked at No. 29 on the "Billboard" 200 and No. 9 on the Top Internet Albums chart. In 2008, the New Kids on the Block reunited and released 2 top 40 hits and went on a successful tour. In the fall of 2010, they teamed with the Backstreet Boys (BSB), creating the boy band NKOTBSB, and toured in summer 2011.


title: Jordan Knight

text: In 2005, Knight released an EP titled "The Fix" supported by the lead single "Where Is Your Heart Tonight", which reached its peak at No. 12 on the "Billboard" Adult Contemporary chart. He continued to tour extensively in 2005–2006 promoting the EP.


title: Jordan Knight

text: In September 2006, Knight's next album, "Love Songs", was released by Transcontinental Records. The first single was "Say Goodbye", a duet with Deborah Gibson, that peaked at No. 24 on the "Billboard" Adult Contemporary chart.


title: Jordan Knight

text: On May 31, 2011, Knight released his third solo album, "Unfinished". The album reached No. 8 on the US "Billboard" Independent Albums chart, No. 48 on the US "Billboard" 200 and No. 55 in Canada. He announced began his Live and Unfinished Tour on December 11, 2011. Knight performed the announced dates with Boston-based band Elevation Theory.


title: Jordan Knight

text: In 2014, Knight teamed up with Nick Carter for the release of the album "Nick & Knight". The duo toured throughout the fall of that year in support of the album.


title: Jordan Knight

text: Knight was a judge on the "American Idol" spin-off, "American Juniors". He was a third-season cast member on the VH1 reality television series "The Surreal Life" with other celebrities in 2004. He later appeared in the 2007 spin-off "", but left during the filming of the premiere episode because of the death of his maternal grandmother.


title: Jordan Knight

text: In 2005, Knight appeared on the British show "Hit Me Baby One More Time", where he performed "Give It To You", as well as a cover of "Let Me Love You" by Mario.


title: Jordan Knight

text: In September 2005, Knight also starred in a British documentary on Five in the UK called "Trust Me – I'm a Holiday Rep". Six celebrities spent 10 days in the role of an Olympic Holidays holiday rep in Ayia Napa, Cyprus. He initially lacked enthusiasm for the role, which he blamed to some extent on his shyness, but came to enjoy it. In his final debriefing he earned praise from the head reps, who said they would (hypothetically) offer him a job as a children's and transfer rep.


title: Jordan Knight

text: Knight also appeared on the game show "Identity", hosted by Penn Jillette. In September 2011, he featured as a judge on the CBC show "Cover Me Canada".


title: Jordan Knight

text: Knight has been married to Evelyn Melendez since 2004. They have two sons. Knight lives in Milton, Massachusetts.


title: Ice

text: Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color.


title: Ice

text: In the Solar System, ice is abundant and occurs naturally from as close to the Sun as Mercury to as far away as the Oort cloud objects. Beyond the Solar System, it occurs as interstellar ice. It is abundant on Earth's surfaceparticularly in the polar regions and above the snow lineand, as a common form of precipitation and deposition, plays a key role in Earth's water cycle and climate. It falls as snowflakes and hail or occurs as frost, icicles or ice spikes and aggregates from snow as glaciers and ice sheets.


title: Ice

text: Ice exhibits at least eighteen phases (packing geometries), depending on temperature and pressure. When water is cooled rapidly (quenching), up to three types of amorphous ice can form depending on its history of pressure and temperature. When cooled slowly, correlated proton tunneling occurs below (, ) giving rise to macroscopic quantum phenomena. Virtually all ice on Earth's surface and in its atmosphere is of a hexagonal crystalline structure denoted as ice I (spoken as "ice one h") with minute traces of cubic ice, denoted as ice I and, more recently found, Ice VII inclusions in diamonds. The most common phase transition to ice I occurs when liquid water is cooled below (, ) at standard atmospheric pressure. It may also be deposited directly by water vapor, as happens in the formation of frost. The transition from ice to water is melting and from ice directly to water vapor is sublimation.


title: Ice

text: As a naturally occurring crystalline inorganic solid with an ordered structure, ice is considered to be a mineral. It possesses a regular crystalline structure based on the molecule of water, which consists of a single oxygen atom covalently bonded to two hydrogen atoms, or H–O–H. However, many of the physical properties of water and ice are controlled by the formation of hydrogen bonds between adjacent oxygen and hydrogen atoms; while it is a weak bond, it is nonetheless critical in controlling the structure of both water and ice.


title: Ice

text: An unusual property of water is that its solid form—ice frozen at atmospheric pressure—is approximately 8.3% less dense than its liquid form; this is equivalent to a volumetric expansion of 9%. The density of ice is 0.9167–0.9168 g/cm at 0 °C and standard atmospheric pressure (101,325 Pa), whereas water has a density of 0.9998–0.999863 g/cm at the same temperature and pressure. Liquid water is densest, essentially 1.00 g/cm, at 4 °C and begins to lose its density as the water molecules begin to form the hexagonal crystals of ice as the freezing point is reached. This is due to hydrogen bonding dominating the intermolecular forces, which results in a packing of molecules less compact in the solid. Density of ice increases slightly with decreasing temperature and has a value of 0.9340 g/cm at −180 °C (93 K).


title: Ice

text: When water freezes, it increases in volume (about 9% for fresh water). The effect of expansion during freezing can be dramatic, and ice expansion is a basic cause of freeze-thaw weathering of rock in nature and damage to building foundations and roadways from frost heaving. It is also a common cause of the flooding of houses when water pipes burst due to the pressure of expanding water when it freezes.


title: Ice

text: The result of this process is that ice (in its most common form) floats on liquid water, which is an important feature in Earth's biosphere. It has been argued that without this property, natural bodies of water would freeze, in some cases permanently, from the bottom up, resulting in a loss of bottom-dependent animal and plant life in fresh and sea water. Sufficiently thin ice sheets allow light to pass through while protecting the underside from short-term weather extremes such as wind chill. This creates a sheltered environment for bacterial and algal colonies. When sea water freezes, the ice is riddled with brine-filled channels which sustain sympagic organisms such as bacteria, algae, copepods and annelids, which in turn provide food for animals such as krill and specialised fish like the bald notothen, fed upon in turn by larger animals such as emperor penguins and minke whales.


title: Ice

text: When ice melts, it absorbs as much energy as it would take to heat an equivalent mass of water by 80 °C. During the melting process, the temperature remains constant at 0 °C. While melting, any energy added breaks the hydrogen bonds between ice (water) molecules. Energy becomes available to increase the thermal energy (temperature) only after enough hydrogen bonds are broken that the ice can be considered liquid water. The amount of energy consumed in breaking hydrogen bonds in the transition from ice to water is known as the "heat of fusion".


title: Ice

text: As with water, ice absorbs light at the red end of the spectrum preferentially as the result of an overtone of an oxygen–hydrogen (O–H) bond stretch. Compared with water, this absorption is shifted toward slightly lower energies. Thus, ice appears blue, with a slightly greener tint than liquid water. Since absorption is cumulative, the color effect intensifies with increasing thickness or if internal reflections cause the light to take a longer path through the ice.


title: Ice

text: Other colors can appear in the presence of light absorbing impurities, where the impurity is dictating the color rather than the ice itself. For instance, icebergs containing impurities (e.g., sediments, algae, air bubbles) can appear brown, grey or green.


title: Ice

text: Because ice in natural environments is usually close to its melting temperature, its hardness shows pronounced temperature variations. At its melting point, ice has a Mohs hardness of 2 or less, but the hardness increases to about 4 at a temperature of and to 6 at a temperature of , the vaporization point of solid carbon dioxide (dry ice).


title: Ice

text: Ice may be any one of the 19 known solid crystalline phases of water, or in an amorphous solid state at various densities.


title: Ice

text: Most liquids under increased pressure freeze at "higher" temperatures because the pressure helps to hold the molecules together. However, the strong hydrogen bonds in water make it different: for some pressures higher than , water freezes at a temperature "below" 0 °C, as shown in the phase diagram below. The melting of ice under high pressures is thought to contribute to the movement of glaciers.


title: Ice

text: Ice, water, and water vapour can coexist at the triple point, which is exactly at a pressure of 611.657 Pa. The kelvin was in fact defined as of the difference between this triple point and absolute zero, though this definition changed in May 2019. Unlike most other solids, ice is difficult to superheat. In an experiment, ice at −3 °C was superheated to about 17 °C for about 250 picoseconds.


title: Ice

text: Subjected to higher pressures and varying temperatures, ice can form in 19 separate known crystalline phases. With care, at least 15 of these phases (one of the known exceptions being ice X) can be recovered at ambient pressure and low temperature in metastable form. The types are differentiated by their crystalline structure, proton ordering, and density. There are also two metastable phases of ice under pressure, both fully hydrogen-disordered; these are IV and XII. Ice XII was discovered in 1996. In 2006, XIII and XIV were discovered. Ices XI, XIII, and XIV are hydrogen-ordered forms of ices I, V, and XII respectively. In 2009, ice XV was found at extremely high pressures and −143 °C. At even higher pressures, ice is predicted to become a metal; this has been variously estimated to occur at 1.55 TPa or 5.62 TPa.


title: Ice

text: As well as crystalline forms, solid water can exist in amorphous states as amorphous ice (ASW) of varying densities. Water in the interstellar medium is dominated by amorphous ice, making it likely the most common form of water in the universe. Low-density ASW (LDA), also known as hyperquenched glassy water, may be responsible for noctilucent clouds on Earth and is usually formed by deposition of water vapor in cold or vacuum conditions. High-density ASW (HDA) is formed by compression of ordinary ice I or LDA at GPa pressures. Very-high-density ASW (VHDA) is HDA slightly warmed to 160 K under 1–2 GPa pressures.


title: Ice

text: In outer space, hexagonal crystalline ice (the predominant form found on Earth) is extremely rare. Amorphous ice is more common; however, hexagonal crystalline ice can be formed by volcanic action.


title: Ice

text: Ice from a theorized superionic water may possess two crystalline structures. At pressures in excess of such "superionic ice" would take on a body-centered cubic structure. However, at pressures in excess of the structure may shift to a more stable face-centered cubic lattice. It is speculated that superionic ice could compose the interior of ice giants such as Uranus and Neptune.


title: Ice

text: The low coefficient of friction ("slipperiness") of ice has been attributed to the pressure of an object coming into contact with the ice, melting a thin layer of the ice and allowing the object to glide across the surface. For example, the blade of an ice skate, upon exerting pressure on the ice, would melt a thin layer, providing lubrication between the ice and the blade. This explanation, called "pressure melting", originated in the 19th century. However, it does not account for skating on ice temperatures lower than , which is often skated upon. Also, the effect of pressure melting is too small to account for the reduced friction as commonly experienced.


title: Ice

text: A second theory describing the coefficient of friction of ice suggested that ice molecules at the interface cannot properly bond with the molecules of the mass of ice beneath (and thus are free to move like molecules of liquid water). These molecules remain in a semi-liquid state, providing lubrication regardless of pressure against the ice exerted by any object. However, the significance of this hypothesis is disputed by experiments showing a high coefficient of friction for ice using atomic force microscopy.


title: Ice

text: A third theory is "friction heating", which suggests that friction of the material is the cause of the ice layer melting. However, this theory does not sufficiently explain why ice is slippery when standing still even at below-zero temperatures.


title: Ice

text: A comprehensive theory of ice friction takes into account all the above-mentioned friction mechanisms. This model allows quantitative estimation of the friction coefficient of ice against various materials as a function of temperature and sliding speed. In typical conditions related to winter sports and tires of a vehicle on ice, melting of a thin ice layer due to the frictional heating is the primary reason for the slipperiness. The mechanism controlling the frictional properties of ice is still an active area of scientific study.


title: Ice

text: The term that collectively describes all of the parts of the Earth's surface where water is in frozen form is the "cryosphere." Ice is an important component of the global climate, particularly in regard to the water cycle. Glaciers and snowpacks are an important storage mechanism for fresh water; over time, they may sublimate or melt. Snowmelt is an important source of seasonal fresh water. The World Meteorological Organization defines several kinds of ice depending on origin, size, shape, influence and so on. Clathrate hydrates are forms of ice that contain gas molecules trapped within its crystal lattice.


title: Ice

text: Ice that is found at sea may be in the form of drift ice floating in the water, fast ice fixed to a shoreline or anchor ice if attached to the sea bottom. Ice which calves (breaks off) from an ice shelf or glacier may become an iceberg. Sea ice can be forced together by currents and winds to form pressure ridges up to tall. Navigation through areas of sea ice occurs in openings called "polynyas" or "leads" or requires the use of a special ship called an "icebreaker".


title: Ice

text: Ice on land ranges from the largest type called an "ice sheet" to smaller ice caps and ice fields to glaciers and ice streams to the snow line and snow fields.


title: Ice

text: Aufeis is layered ice that forms in Arctic and subarctic stream valleys. Ice, frozen in the stream bed, blocks normal groundwater discharge, and causes the local water table to rise, resulting in water discharge on top of the frozen layer. This water then freezes, causing the water table to rise further and repeat the cycle. The result is a stratified ice deposit, often several meters thick.


title: Ice

text: Freezing rain is a type of winter storm called an ice storm where rain falls and then freezes producing a glaze of ice. Ice can also form icicles, similar to stalactites in appearance, or stalagmite-like forms as water drips and re-freezes.


title: Ice

text: The term "ice dam" has three meanings (others discussed below). On structures, an ice dam is the buildup of ice on a sloped roof which stops melt water from draining properly and can cause damage from water leaks in buildings.


title: Ice

text: Ice which forms on moving water tends to be less uniform and stable than ice which forms on calm water. Ice jams (sometimes called "ice dams"), when broken chunks of ice pile up, are the greatest ice hazard on rivers. Ice jams can cause flooding, damage structures in or near the river, and damage vessels on the river. Ice jams can cause some hydropower industrial facilities to completely shut down. An ice dam is a blockage from the movement of a glacier which may produce a proglacial lake. Heavy ice flows in rivers can also damage vessels and require the use of an icebreaker to keep navigation possible.


title: Ice

text: Ice forms on calm water from the shores, a thin layer spreading across the surface, and then downward. Ice on lakes is generally four types: primary, secondary, superimposed and agglomerate. Primary ice forms first. Secondary ice forms below the primary ice in a direction parallel to the direction of the heat flow. Superimposed ice forms on top of the ice surface from rain or water which seeps up through cracks in the ice which often settles when loaded with snow.


title: Ice

text: An ice shove occurs when ice movement, caused by ice expansion and/or wind action, occurs to the extent that ice pushes onto the shores of lakes, often displacing sediment that makes up the shoreline.


title: Ice

text: Rime is a type of ice formed on cold objects when drops of water crystallize on them. This can be observed in foggy weather, when the temperature drops during the night. Soft rime contains a high proportion of trapped air, making it appear white rather than transparent, and giving it a density about one quarter of that of pure ice. Hard rime is comparatively dense.


title: Ice

text: Ice pellets are a form of precipitation consisting of small, translucent balls of ice. This form of precipitation is also referred to as "sleet" by the United States National Weather Service. (In British English "sleet" refers to a mixture of rain and snow.) Ice pellets are usually smaller than hailstones. They often bounce when they hit the ground, and generally do not freeze into a solid mass unless mixed with freezing rain. The METAR code for ice pellets is "PL".


title: Ice

text: Ice pellets form when a layer of above-freezing air is located between above the ground, with sub-freezing air both above and below it. This causes the partial or complete melting of any snowflakes falling through the warm layer. As they fall back into the sub-freezing layer closer to the surface, they re-freeze into ice pellets. However, if the sub-freezing layer beneath the warm layer is too small, the precipitation will not have time to re-freeze, and freezing rain will be the result at the surface. A temperature profile showing a warm layer above the ground is most likely to be found in advance of a warm front during the cold season, but can occasionally be found behind a passing cold front.


title: Ice

text: Like other precipitation, hail forms in storm clouds when supercooled water droplets freeze on contact with condensation nuclei, such as dust or dirt. The storm's updraft blows the hailstones to the upper part of the cloud. The updraft dissipates and the hailstones fall down, back into the updraft, and are lifted up again. Hail has a diameter of or more. Within METAR code, GR is used to indicate larger hail, of a diameter of at least and GS for smaller. Stones just larger than golf ball-sized are one of the most frequently reported hail sizes. Hailstones can grow to and weigh more than . In large hailstones, latent heat released by further freezing may melt the outer shell of the hailstone. The hailstone then may undergo 'wet growth', where the liquid outer shell collects other smaller hailstones. The hailstone gains an ice layer and grows increasingly larger with each ascent. Once a hailstone becomes too heavy to be supported by the storm's updraft, it falls from the cloud.


title: Ice

text: Hail forms in strong thunderstorm clouds, particularly those with intense updrafts, high liquid water content, great vertical extent, large water droplets, and where a good portion of the cloud layer is below freezing . Hail-producing clouds are often identifiable by their green coloration. The growth rate is maximized at about , and becomes vanishingly small much below as supercooled water droplets become rare. For this reason, hail is most common within continental interiors of the mid-latitudes, as hail formation is considerably more likely when the freezing level is below the altitude of . Entrainment of dry air into strong thunderstorms over continents can increase the frequency of hail by promoting evaporational cooling which lowers the freezing level of thunderstorm clouds giving hail a larger volume to grow in. Accordingly, hail is actually less common in the tropics despite a much higher frequency of thunderstorms than in the mid-latitudes because the atmosphere over the tropics tends to be warmer over a much greater depth. Hail in the tropics occurs mainly at higher elevations.


title: Ice

text: Snow crystals form when tiny supercooled cloud droplets (about 10 μm in diameter) freeze. These droplets are able to remain liquid at temperatures lower than , because to freeze, a few molecules in the droplet need to get together by chance to form an arrangement similar to that in an ice lattice; then the droplet freezes around this "nucleus". Experiments show that this "homogeneous" nucleation of cloud droplets only occurs at temperatures lower than . In warmer clouds an aerosol particle or "ice nucleus" must be present in (or in contact with) the droplet to act as a nucleus. Our understanding of what particles make efficient ice nuclei is poor – what we do know is they are very rare compared to that cloud condensation nuclei on which liquid droplets form. Clays, desert dust and biological particles may be effective, although to what extent is unclear. Artificial nuclei are used in cloud seeding. The droplet then grows by condensation of water vapor onto the ice surfaces.


title: Ice

text: So-called "diamond dust", also known as ice needles or ice crystals, forms at temperatures approaching due to air with slightly higher moisture from aloft mixing with colder, surface-based air. The METAR identifier for diamond dust within international hourly weather reports is "IC".


title: Ice

text: The melting of ice means entails the breaking of hydrogen bonds between the water molecules. The ordering of the molecules in the solid breaks down to a less ordered state and the solid melts to become a liquid. This is achieved by increasing the internal energy of the ice beyond the melting point. When ice melts it absorbs as much energy as would be required to heat an equivalent amount of water by 80 °C. While melting, the temperature of the ice surface remains constant at 0 °C. The rate of the melting process depends on the efficiency of the energy exchange process. An ice surface in fresh water melts solely by free convection with a rate that depends linearly on the water temperature, "T", when "T" is less than 3.98 °C, and superlinearly when "T" is equal to or greater than 3.98 °C, with the rate being proportional to (T − 3.98 °C), with "α" =  for "T" much greater than 8 °C, and α =  for in between temperatures "T".


title: Ice

text: In salty ambient conditions, dissolution rather than melting often causes the ablation of ice. For example, the temperature of the Arctic Ocean is generally below the melting point of ablating sea ice. The phase transition from solid to liquid is achieved by mixing salt and water molecules, similar to the dissolution of sugar in water, even though the water temperature is far below the melting point of the sugar. Thus the dissolution rate is limited by salt transport whereas melting can occur at much higher rates that are characteristic for heat transport.


title: Ice

text: Humans have used ice for cooling and food preservation for centuries, relying on harvesting natural ice in various forms and then transitioning to the mechanical production of the material. Ice also presents a challenge to transportation in various forms and a setting for winter sports.