title: Syrian civil war

text: The conflict holds the record for the largest sum ever requested by UN agencies for a single humanitarian emergency, $6.5 billion worth of requests of December 2013. The international humanitarian response to the conflict in Syria is coordinated by the United Nations Office for the Coordination of Humanitarian Affairs (UNOCHA) in accordance with General Assembly Resolution 46/182. The primary framework for this coordination is the Syria Humanitarian Assistance Response Plan (SHARP) which appealed for US$1.41 billion to meet the humanitarian needs of Syrians affected by the conflict. Official United Nations data on the humanitarian situation and response is available at an official website managed by UNOCHA Syria (Amman). UNICEF is also working alongside these organizations to provide vaccinations and care packages to those in need. Financial information on the response to the SHARP and assistance to refugees and for cross-border operations can be found on UNOCHA's Financial Tracking Service. As of 19 September 2015, the top ten donors to Syria were United States, European Commission, United Kingdom, Kuwait, Germany, Saudi Arabia, Canada, Japan, UAE, and Norway.


title: Syrian civil war

text: The difficulty of delivering humanitarian aid to people is indicated by the statistics for January 2015: of the estimated 212,000 people during that month who were besieged by government or opposition forces, 304 were reached with food. USAID and other government agencies in US delivered nearly $385 million of aid items to Syria in 2012 and 2013. The United States has provided food aid, medical supplies, emergency and basic health care, shelter materials, clean water, hygiene education and supplies, and other relief supplies. Islamic Relief has stocked 30 hospitals and sent hundreds of thousands of medical and food parcels.


title: Syrian civil war

text: Other countries in the region have also contributed various levels of aid. Iran has been exporting between 500 and 800 tonnes of flour daily to Syria. Israel supplied aid through Operation Good Neighbor, providing medical treatment to 750 Syrians in a field hospital located in Golan Heights where rebels say that 250 of their fighters were treated. Israel established two medical centers inside Syria. Israel also delivered heating fuel, diesel fuel, seven electric generators, water pipes, educational materials, flour for bakeries, baby food, diapers, shoes and clothing. Syrian refugees in Lebanon make up one quarter of Lebanon's population, mostly consisting of women and children. In addition, Russia has said it created six humanitarian aid centers within Syria to support 3000 refugees in 2016.


title: Syrian civil war

text: On 9 April 2020, the UN dispatched 51 truckloads of humanitarian aid to Idlib. The organization said that the aid would be distributed among civilians stranded in the north-western part of the country.


title: Syrian civil war

text: On 30 April 2020, Human Rights Watch condemned the Syrian authorities for their longstanding restriction on the entry of aid supplies. It also demanded the World Health Organization to keep pushing the UN to allow medical aid and other essentials to reach Syria via the Iraq border crossing, to prevent the spread of COVID-19 in the war-torn nation. The aid supplies, if allowed, will allow the Syrian population to protect themselves from contracting the COVID-19 virus.


title: Syrian civil war

text: As of December 2019, a diplomatic dispute is occurring at the UN over re-authorization of cross-border aid for refugees. China and Russia oppose the draft resolution that seeks to re-authorize crossing points in Turkey, Iraq, and Jordan; China and Russia, as allies of Assad, seek to close the two crossing points in Iraq and Jordan, and to leave only the two crossing points in Turkey active. The current authorization expired on 10 January 2020.


title: Syrian civil war

text: All of the ten individuals representing the non-permanent members of the Security Council stood in the corridor outside of the chamber speaking to the press to state that all four crossing points are crucial and must be renewed.


title: Syrian civil war

text: United Nations official Mark Lowcock is asking the UN to re-authorize cross-border aid to enable aid to continue to reach refugees in Syria. He says there is no other way to deliver the aid that is needed. He noted that four million refugees out of the over eleven million refugees who need assistance are being reached through four specific international crossing points. Lowcock serves as the United Nations Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator and the Head of the United Nations Office for the Coordination of Humanitarian Affairs.<ref name="UN VOA 12/2019"></ref>


title: Syrian civil war

text: Russia, aided by China's support, has vetoed the resolution to retain all four border crossings. An alternate resolution also did not pass. The US strongly criticized the vetoes and opposition by Russia and China. China explained the reason for veto is the concern of "unilateral coercive measures" by certain states causing humanitarian suffering on the Syrian people. It views lifting all unilateral sanctions respecting Syrian sovereignty and for humanitarian reasons is a must.


title: Syrian civil war

text: , the war has affected 290 heritage sites, severely damaged 104, and completely destroyed 24. Five of the six UNESCO World Heritage Sites in Syria have been damaged. Destruction of antiquities has been caused by shelling, army entrenchment, and looting at various tells, museums, and monuments. A group called Syrian Archaeological Heritage Under Threat is monitoring and recording the destruction in an attempt to create a list of heritage sites damaged during the war and to gain global support for the protection and preservation of Syrian archaeology and architecture.


title: Syrian civil war

text: UNESCO listed all six Syria's World Heritage Sites as endangered but direct assessment of damage is not possible. It is known that the Old City of Aleppo was heavily damaged during battles being fought within the district, while Palmyra and Krak des Chevaliers suffered minor damage. Illegal digging is said to be a grave danger, and hundreds of Syrian antiquities, including some from Palmyra, appeared in Lebanon. Three archeological museums are known to have been looted; in Raqqa some artifacts seem to have been destroyed by foreign Islamists due to religious objections.


title: Syrian civil war

text: In 2014 and 2015, following the rise of the Islamic State of Iraq and the Levant, several sites in Syria were destroyed by the group as part of a deliberate destruction of cultural heritage sites. In Palmyra, the group destroyed many ancient statues, the Temples of Baalshamin and Bel, many tombs including the Tower of Elahbel, and part of the Monumental Arch. The 13th-century Palmyra Castle was extensively damaged by retreating militants during the Palmyra offensive in March 2016. ISIL also destroyed ancient statues in Raqqa, and a number of churches, including the Armenian Genocide Memorial Church in Deir ez-Zor.


title: Syrian civil war

text: In January 2018 Turkish airstrikes have seriously damaged an ancient Neo-Hittite temple in Syria's Kurdish-held Afrin region. It was built by the Arameans in the first millennium BC.


title: Syrian civil war

text: According to a September 2019 Syrian Network for Human Rights reports more than 120 Christian churches have been destroyed or damaged in Syria since 2011.


title: Syrian civil war

text: The war has inspired its own particular artwork, done by Syrians. A late summer 2013 exhibition in London at the P21 Gallery showed some of this work, which had to be smuggled out of Syria.


title: Syrian civil war

text: The Syrian civil war is one of the most heavily documented wars in history, despite the extreme dangers that journalists face while in Syria.


title: Syrian civil war

text: On 19 August 2014, American journalist James Foley was executed by ISIL, who said it was in retaliation for the United States operations in Iraq. Foley was kidnapped in Syria in November 2012 by Shabiha militia. ISIL also threatened to execute Steven Sotloff, who was kidnapped at the Syrian-Turkish border in August 2013. There were reports ISIS captured a Japanese national, two Italian nationals, and a Danish national as well. Sotloff was later executed in September 2014. At least 70 journalists have been killed covering the Syrian war, and more than 80 kidnapped, according to the Committee to Protect Journalists. On 22 August 2014, the al-Nusra Front released a video of captured Lebanese soldiers and demanded Hezbollah withdraw from Syria under threat of their execution.


title: Syrian civil war

text: During the early period of the civil war, The Arab League, European Union, the United Nations, and many Western governments quickly condemned the Syrian government's violent response to the protests, and expressed support for the protesters' right to exercise free speech. Initially, many Middle Eastern governments expressed support for Assad, but as the death toll mounted, they switched to a more balanced approach by criticizing violence from both government and protesters. Both the Arab League and the Organisation of Islamic Cooperation suspended Syria's membership. Russia and China vetoed Western-drafted United Nations Security Council resolutions in 2011 and 2012, which would have threatened the Syrian government with targeted sanctions if it continued military actions against protestors.


title: Syrian civil war

text: The US Congress has enacted punitive sanctions on the Syrian government for its actions during the Civil War. These sanctions would penalize any entities lending support to the Syrian government, and any companies operating in Syria. US President Donald Trump tried to protect the Turkish President Erdogan from the effects of such sanctions.


title: Syrian civil war

text: Some activists welcomed this legislation. Some critics contend that these punitive sanctions are likely to backfire or have unintended consequences; they argue that ordinary Syrian people will have fewer economic resources due to these sanctions (and will thus need to rely more the Syrian government and its economic allies and projects), while the sanctions' impact on ruling political elites will be limited.


title: Syrian civil war

text: Mohammad al-Abdallah, executive director of Syria Justice and Accountability Center (SJAC), said that the sanctions will likely hurt ordinary Syrian people, saying, "it is an almost unsolvable unfeasible equation. If they are imposed, they will indirectly harm the Syrian people, and if they are lifted, they will indirectly revive the Syrian regime;" he attributed the sanctions to "political considerations, as the United States does not have weapons and tools in the Syrian file, and sanctions are its only means."


title: Syrian civil war

text: Peter Ford, the former UK Ambassador to Syria, said "...going forward, we're seeing more economic warfare. It seems that the US, having failed to change the regime in Syria by military force or by proxies, is tightening the economic screws and the main reason why the US is keeping hold of the production facilities in eastern Syria. So, the economic situation is becoming more and more serious and dire in Syria and it's a major reason why refugees are not going back."


title: Syrian civil war

text: In June, US Secretary of State Mike Pompeo announced new economic sanctions on Syria targeting foreign business relations with the Syrian government. Under the Caesar Act, the latest sanctions were to be imposed on 39 individuals and entities, including Asma al-Assad, wife of Syrian President Bashar al-Assad.


title: Syrian civil war

text: On 17 June 2020, James F. Jeffrey, Special Representative for Syria Engagement, signalled that the UAE could be hit with sanctions under the Caesar Act if it pushed ahead with normalisation efforts with the Syrian regime.


title: Syrian civil war

text: During the course of the war, there have been several international peace initiatives, undertaken by the Arab League, the United Nations, and other actors. The Syrian government has refused efforts to negotiate with what it describes as armed terrorist groups. On 1 February 2016, the UN announced the formal start of the UN-mediated Geneva Syria peace talks that had been agreed on by the International Syria Support Group (ISSG) in Vienna. On 3 February 2016, the UN Syria peace mediator suspended the talks. On 14 March 2016, Geneva peace talks resumed. The Syrian government stated that discussion of Bashar-al-Assad's presidency "is a red line", however Syria's President Bashar al-Assad said he hoped peace talks in Geneva would lead to concrete results, and stressed the need for a political process in Syria.


title: Syrian civil war

text: A new round of talks between the Syrian government and some groups of Syrian rebels concluded on 24 24 January 2017 in Astana, Kazakhstan, with Russia, Iran and Turkey supporting the ceasefire agreement brokered in late December 2016. The Astana Process talks was billed by a Russian official as a complement to, rather than replacement, of the United Nations-led Geneva Process talks. On 4 May 2017, at the fourth round of the Astana talks, representatives of Russia, Iran, and Turkey signed a memorandum whereby four "de-escalation zones" in Syria would be established, effective of 6 May 2017.


title: Syrian civil war

text: On 18 September 2019, Russia stated the United States and Syrian rebels were obstructing the evacuation process of a refugee camp in southern Syria.


title: Syrian civil war

text: On 28 September 2019, Syria's top diplomat demanded the foreign forces, including that of US and Turkey, to immediately leave the country, saying that the Syrian government holds the right to protect its territory in all possible ways if they remain.


title: Syrian civil war

text: President RT Erdogan said Turkey was left with no choice other than going its own way on the Syria 'safe zone' after a deadline to co-jointly establish a "safe zone" with the US in northern Syria expired in September. The U.S. indicated it would withdraw its forces from northern Syria after Turkey warned of incursion in the region that could instigate fighting with American-backed Kurds.


title: Syrian civil war

text: In October 2019, in response to the Turkish offensive, Russia arranged for negotiations between the Syrian government in Damascus and the Kurdish-led forces. Russia also negotiated a renewal of a cease-fire between Kurds and Turkey that was about to expire.


title: Syrian civil war

text: Russia and Turkey agreed via the Sochi Agreement of 2019 to set up a Second Northern Syria Buffer Zone. Syrian President Assad expressed full support for the deal, as various terms of the agreement also applied to the Syrian government. The SDF stated that they considered themselves as "Syrian and a part of Syria", adding that they would agree to work with the Syrian Government. The SDF officially announced their support for the deal on 27 October.


title: Syrian civil war

text: In late 2019, a new Syrian Constitutional Committee began operating in order to discuss a new settlement and to draft a new constitution for Syria. This committee comprises about 150 members. It includes representatives of the Syrian government, opposition groups, and countries serving as guarantors of the process, such as Russia. However, this committee has faced strong opposition from the Assad government. 50 of the committee members represent the government, and 50 members represent the opposition. Until the Assad government agrees to participate, is unclear whether the third round of talks will proceed on a firm schedule.


title: Syrian civil war

text: In December 2019, the EU held an international conference which condemned any suppression of the Kurds, and called for the self-declared Autonomous Administration in Rojava to be preserved and to be reflected in any new Syrian Constitution. The Kurds are concerned that the independence of their declared Autonomous Administration of North and East Syria (NES) in Rojava might be severely curtailed.


title: Syrian civil war

text: Rojava officials condemned the fact that they were excluded from the peace talks and stated that "having a couple of Kurds" in the committee did not mean that the Syrian Kurds were properly represented in it. The co-chair of the Syrian Democratic Council accused Turkey of vetoing the representation of Syrian Kurds within the committee. The Kurdish administration also organized demonstrations in front of the UN office in Qamishli to protest their exclusion from the committee.


title: Syrian civil war

text: United Nations authorities have estimated that the war in Syria has caused destruction reaching to about $400 billion. According to a Syrian war monitor, over 120 churches have been damaged or demolished by opposition forces in the Syrian war since 2011.


title: Syrian civil war

text: While the war still ongoing, Syrian President Bashar Al-Assad said that Syria would be able to rebuild the war-torn country on its own. , the reconstruction is estimated to cost a minimum of US$400 billion. Assad said he would be able to loan this money from friendly countries, Syrian diaspora and the state treasury. Iran has expressed interest in helping rebuild Syria. One year later this seems to be materializing, Iran and the Syrian government signed a deal where Iran would help rebuild the Syrian energy grid, which has taken damage to 50% of the grid. International donors have been suggested as one financier of the reconstruction. , reports emerged that rebuilding efforts had already started. It was reported that the biggest issue facing the rebuilding process is the lack of building material and a need to make sure the resources that do exist are managed efficiently. The rebuilding effort have so far remained at a limited capacity and has often been focused on certain areas of a city, thus ignoring other areas inhabited by disadvantaged people.


title: Syrian civil war

text: Various efforts are proceeding to rebuild infrastructure in Syria. Russia says it will spend $500 million to modernize Syria's port of Tartus. Russia also said it will build a railway to link Syria with the Persian Gulf. Russia will also contribute to recovery efforts by the UN. Syria awarded oil exploration contracts to two Russian firms.


title: Syrian civil war

text: Syria announced it is in serious dialogue with China to join China's "Belt and Road Initiative" designed to foster investment in infrastructure in over one-hundred developing nations worldwide. On Wednesday 12 January 2022, China and Syria signed a memorandum of understanding in Damascus. The memorandum was signed by Fadi al-Khalil, the Head of Planning and International Cooperation Commission for the Syrian Side and Feng Biao, the Chinese ambassador in Damascus for the Chinese side. The memorandum sees Syria join the initiative whose aim is to help expand cooperation with China and other partner countries in areas such as trade, technology, capital, human movement and cultural exchange. Among other things, it aims to define the future of this cooperation with partner states.


title: Syrian civil war

text: In 2022, a German court sentenced Anwar Raslan, 58, a high-ranking official of President Bashar Al-Assad's regime to life imprisonment after he sought asylum in Germany and was arrested in 2019. He was charged with being complicit to the murder of at least 27 people coupled with the sexual assault and torture of at least another 4,000 people between 29 April 2011, and 7 September 2012. Raslan was a mid-level officer in Branch 251 and oversaw the torture of detainees. His trial was one of an unprecedented nature because Germany took on a trial of crimes committed in the Syrian war and the human rights lawyers took this on under the principle of "universal jurisdiction". Universal Jurisdiction is a concept in German law that allows for serious crimes to be tried in Germany even if they did not happen in the country. His co-defendant Eyad al-Gharib, 44, a low-level officer in Branch 251 was also sentenced to 4 years and 6 months in prison on 24 February 2021. Eyad's duties included the transport of detainees to location where they would be tortured for days on end. It was his knowledge of the fact that torture was happening there that landed him the sentence.


title: Sun

text: The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radiation, and is the most important source of energy for life on Earth.


title: Sun

text: The Sun's radius is about , or 109 times that of Earth. Its mass is about 330,000 times that of Earth, comprising about 99.86% of the total mass of the Solar System. Roughly three-quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.


title: Sun

text: The Sun is a G-type main-sequence star (G2V). As such, it is informally, and not completely accurately, referred to as a yellow dwarf (its light is actually white). It formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most of this matter gathered in the center, whereas the rest flattened into an orbiting disk that became the Solar System. The central mass became so hot and dense that it eventually initiated nuclear fusion in its core. It is thought that almost all stars form by this process.


title: Sun

text: Every second, the Sun's core fuses about 600 million tons of hydrogen into helium, and in the process converts 4 million tons of matter into energy. This energy, which can take between 10,000 and 170,000 years to escape the core, is the source of the Sun's light and heat. When hydrogen fusion in its core has diminished to the point at which the Sun is no longer in hydrostatic equilibrium, its core will undergo a marked increase in density and temperature while its outer layers expand, eventually transforming the Sun into a red giant. It is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury and Venus, and render Earth uninhabitable – but not for about five billion years. After this, it will shed its outer layers and become a dense type of cooling star known as a white dwarf, and no longer produce energy by fusion, but still glow and give off heat from its previous fusion.


title: Sun

text: The enormous effect of the Sun on Earth has been recognized since prehistoric times. The Sun was thought of by some cultures as a deity. The synodic rotation of Earth and its orbit around the Sun are the basis of some solar calendars. The predominant calendar in use today is the Gregorian calendar which is based upon the standard 16th-century interpretation of the Sun's observed movement as actual movement.


title: Sun

text: The English word "sun" developed from Old English . Cognates appear in other Germanic languages, including West Frisian , Dutch , Low German , Standard German , Bavarian , Old Norse , and Gothic . All these words stem from Proto-Germanic . This is ultimately related to the word for "sun" in other branches of the Indo-European language family, though in most cases a nominative stem with an "l" is found, rather than the genitive stem in "n", as for example in Latin , ancient Greek (), Welsh and Russian (; pronounced "sontse"), as well as (with *l > "r") Sanskrit () and Persian (). Indeed, the "l"-stem survived in Proto-Germanic as well, as , which gave rise to Gothic (alongside ) and Old Norse prosaic (alongside poetic ), and through it the words for "sun" in the modern Scandinavian languages: Swedish and Danish , Icelandic , etc.


title: Sun

text: The principal adjectives for the Sun in English are "sunny" for sunlight and, in technical contexts, "solar" (), from Latin – the latter found in terms such as "solar day", "solar eclipse" and "Solar System" (occasionally "Sol system"). From the Greek comes the rare adjective "heliac" (). In English, the Greek and Latin words occur in poetry as personifications of the Sun, Helios () and Sol (), while in science fiction "Sol" may be used as a name for the Sun to distinguish it from other stars. The term "sol" with a lower-case "s" is used by planetary astronomers for the duration of a solar day on another planet such as Mars.


title: Sun

text: The English weekday name "Sunday" stems from Old English "sun's day", a Germanic interpretation of the Latin phrase , itself a translation of the ancient Greek () 'day of the sun'. The astronomical symbol for the Sun is a circle with a center dot, . It is used for such units as "M" (Solar mass), "R" (Solar radius) and "L" (Solar luminosity).


title: Sun

text: The Sun is a G-type main-sequence star that constitutes about 99.86% of the mass of the Solar System. The Sun has an absolute magnitude of +4.83, estimated to be brighter than about 85% of the stars in the Milky Way, most of which are red dwarfs. The Sun is a Population I, or heavy-element-rich, star. The formation of the Sun may have been triggered by shockwaves from one or more nearby supernovae. This is suggested by a high abundance of heavy elements in the Solar System, such as gold and uranium, relative to the abundances of these elements in so-called Population II, heavy-element-poor, stars. The heavy elements could most plausibly have been produced by endothermic nuclear reactions during a supernova, or by transmutation through neutron absorption within a massive second-generation star.


title: Sun

text: The Sun is by far the brightest object in the Earth's sky, with an apparent magnitude of −26.74. This is about 13 billion times brighter than the next brightest star, Sirius, which has an apparent magnitude of −1.46.


title: Sun

text: The Sun does not have a definite boundary, but its density decreases exponentially with increasing height above the photosphere. For the purpose of measurement, the Sun's radius is considered to be the distance from its center to the edge of the photosphere, the apparent visible surface of the Sun. By this measure, the Sun is a near-perfect sphere with an oblateness estimated at 9 millionths, which means that its polar diameter differs from its equatorial diameter by only . The tidal effect of the planets is weak and does not significantly affect the shape of the Sun. The Sun rotates faster at its equator than at its poles. This differential rotation is caused by convective motion due to heat transport and the Coriolis force due to the Sun's rotation. In a frame of reference defined by the stars, the rotational period is approximately 25.6 days at the equator and 33.5 days at the poles. Viewed from Earth as it orbits the Sun, the "apparent rotational period" of the Sun at its equator is about 28 days. Viewed from a vantage point above its north pole, the Sun rotates counterclockwise around its axis of spin.


title: Sun

text: The Sun is composed primarily of the chemical elements hydrogen and helium. At this time in the Sun's life, they account for 74.9% and 23.8%, respectively, of the mass of the Sun in the photosphere. All heavier elements, called "metals" in astronomy, account for less than 2% of the mass, with oxygen (roughly 1% of the Sun's mass), carbon (0.3%), neon (0.2%), and iron (0.2%) being the most abundant.


title: Sun

text: The Sun's original chemical composition was inherited from the interstellar medium out of which it formed. Originally it would have contained about 71.1% hydrogen, 27.4% helium, and 1.5% heavier elements. The hydrogen and most of the helium in the Sun would have been produced by Big Bang nucleosynthesis in the first 20 minutes of the universe, and the heavier elements were produced by previous generations of stars before the Sun was formed, and spread into the interstellar medium during the final stages of stellar life and by events such as supernovae.


title: Sun

text: Since the Sun formed, the main fusion process has involved fusing hydrogen into helium. Over the past 4.6 billion years, the amount of helium and its location within the Sun has gradually changed. Within the core, the proportion of helium has increased from about 24% to about 60% due to fusion, and some of the helium and heavy elements have settled from the photosphere towards the center of the Sun because of gravity. The proportions of heavier elements is unchanged. Heat is transferred outward from the Sun's core by radiation rather than by convection (see Radiative zone below), so the fusion products are not lifted outward by heat; they remain in the core and gradually an inner core of helium has begun to form that cannot be fused because presently the Sun's core is not hot or dense enough to fuse helium. In the current photosphere, the helium fraction is reduced, and the metallicity is only 84% of what it was in the protostellar phase (before nuclear fusion in the core started). In the future, helium will continue to accumulate in the core, and in about 5 billion years this gradual build-up will eventually cause the Sun to exit the main sequence and become a red giant.


title: Sun

text: The chemical composition of the photosphere is normally considered representative of the composition of the primordial Solar System. The solar heavy-element abundances described above are typically measured both using spectroscopy of the Sun's photosphere and by measuring abundances in meteorites that have never been heated to melting temperatures. These meteorites are thought to retain the composition of the protostellar Sun and are thus not affected by the settling of heavy elements. The two methods generally agree well.


title: Sun

text: The core of the Sun extends from the center to about 20–25% of the solar radius. It has a density of up to (about 150 times the density of water) and a temperature of close to 15.7 million Kelvin (K). By contrast, the Sun's surface temperature is approximately . Recent analysis of SOHO mission data favors a faster rotation rate in the core than in the radiative zone above. Through most of the Sun's life, energy has been produced by nuclear fusion in the core region through the proton–proton chain; this process converts hydrogen into helium. Currently, only 0.8% of the energy generated in the Sun comes from another sequence of fusion reactions called the CNO cycle, though this proportion is expected to increase as the Sun becomes older and more luminous.


title: Sun

text: The core is the only region in the Sun that produces an appreciable amount of thermal energy through fusion; 99% of the power is generated within 24% of the Sun's radius, and by 30% of the radius, fusion has stopped nearly entirely. The remainder of the Sun is heated by this energy as it is transferred outwards through many successive layers, finally to the solar photosphere where it escapes into space through radiation (photons) or advection (massive particles).


title: Sun

text: The proton–proton chain occurs around times each second in the core, converting about 3.7 protons into alpha particles (helium nuclei) every second (out of a total of ~8.9 free protons in the Sun), or about . However, each proton (on average) takes around 9 billion years to fuse with one another using the PP chain. Fusing four free protons (hydrogen nuclei) into a single alpha particle (helium nucleus) releases around 0.7% of the fused mass as energy, so the Sun releases energy at the mass–energy conversion rate of 4.26 million metric tons per second (which requires 600 metric megatons of hydrogen), for 384.6 yottawatts (), or 9.192 megatons of TNT per second. The large power output of the Sun is mainly due to the huge size and density of its core (compared to Earth and objects on Earth), with only a fairly small amount of power being generated per cubic metre. Theoretical models of the Sun's interior indicate a maximum power density, or energy production, of approximately 276.5 watts per cubic metre at the center of the core, which is about the same power density inside a compost pile.


title: Sun

text: The fusion rate in the core is in a self-correcting equilibrium: a slightly higher rate of fusion would cause the core to heat up more and expand slightly against the weight of the outer layers, reducing the density and hence the fusion rate and correcting the perturbation; and a slightly lower rate would cause the core to cool and shrink slightly, increasing the density and increasing the fusion rate and again reverting it to its present rate.


title: Sun

text: The radiative zone is the thickest layer of the sun, at 0.45 solar radii. From the core out to about 0.7 solar radii, thermal radiation is the primary means of energy transfer. The temperature drops from approximately 7 million to 2 million Kelvin with increasing distance from the core. This temperature gradient is less than the value of the adiabatic lapse rate and hence cannot drive convection, which explains why the transfer of energy through this zone is by radiation instead of thermal convection. Ions of hydrogen and helium emit photons, which travel only a brief distance before being reabsorbed by other ions. The density drops a hundredfold (from 20 g/cm to 0.2 g/cm) between 0.25 solar radii and 0.7 radii, the top of the radiative zone.


title: Sun

text: The radiative zone and the convective zone are separated by a transition layer, the tachocline. This is a region where the sharp regime change between the uniform rotation of the radiative zone and the differential rotation of the convection zone results in a large shear between the two—a condition where successive horizontal layers slide past one another. Presently, it is hypothesized (see Solar dynamo) that a magnetic dynamo within this layer generates the Sun's magnetic field.


title: Sun

text: The Sun's convection zone extends from 0.7 solar radii (500,000 km) to near the surface. In this layer, the solar plasma is not dense enough or hot enough to transfer the heat energy of the interior outward via radiation. Instead, the density of the plasma is low enough to allow convective currents to develop and move the Sun's energy outward towards its surface. Material heated at the tachocline picks up heat and expands, thereby reducing its density and allowing it to rise. As a result, an orderly motion of the mass develops into thermal cells that carry the majority of the heat outward to the Sun's photosphere above. Once the material diffusively and radiatively cools just beneath the photospheric surface, its density increases, and it sinks to the base of the convection zone, where it again picks up heat from the top of the radiative zone and the convective cycle continues. At the photosphere, the temperature has dropped to 5,700 K (350-fold) and the density to only 0.2 g/m (about 1/10,000 the density of air at sea level, and 1 millionth that of the inner layer of the convective zone).


title: Sun

text: The thermal columns of the convection zone form an imprint on the surface of the Sun giving it a granular appearance called the solar granulation at the smallest scale and supergranulation at larger scales. Turbulent convection in this outer part of the solar interior sustains "small-scale" dynamo action over the near-surface volume of the Sun. The Sun's thermal columns are Bénard cells and take the shape of roughly hexagonal prisms.


title: Sun

text: The visible surface of the Sun, the photosphere, is the layer below which the Sun becomes opaque to visible light. Photons produced in this layer escape the Sun through the transparent solar atmosphere above it and become solar radiation, sunlight. The change in opacity is due to the decreasing amount of H ions, which absorb visible light easily. Conversely, the visible light we see is produced as electrons react with hydrogen atoms to produce H ions.


title: Sun

text: The photosphere is tens to hundreds of kilometers thick, and is slightly less opaque than air on Earth. Because the upper part of the photosphere is cooler than the lower part, an image of the Sun appears brighter in the center than on the edge or "limb" of the solar disk, in a phenomenon known as limb darkening. The spectrum of sunlight has approximately the spectrum of a black-body radiating at , interspersed with atomic absorption lines from the tenuous layers above the photosphere. The photosphere has a particle density of ~10 m (about 0.37% of the particle number per volume of Earth's atmosphere at sea level). The photosphere is not fully ionized—the extent of ionization is about 3%, leaving almost all of the hydrogen in atomic form.


title: Sun

text: During early studies of the optical spectrum of the photosphere, some absorption lines were found that did not correspond to any chemical elements then known on Earth. In 1868, Norman Lockyer hypothesized that these absorption lines were caused by a new element that he dubbed "helium", after the Greek Sun god Helios. Twenty-five years later, helium was isolated on Earth.


title: Sun

text: The coolest layer of the Sun is a temperature minimum region extending to about above the photosphere, and has a temperature of about . This part of the Sun is cool enough to allow the existence of simple molecules such as carbon monoxide and water, which can be detected via their absorption spectra.


title: Sun

text: The chromosphere, transition region, and corona are much hotter than the surface of the Sun. The reason is not well understood, but evidence suggests that Alfvén waves may have enough energy to heat the corona.


title: Sun

text: Above the temperature minimum layer is a layer about thick, dominated by a spectrum of emission and absorption lines. It is called the "chromosphere" from the Greek root "chroma", meaning color, because the chromosphere is visible as a colored flash at the beginning and end of total solar eclipses. The temperature of the chromosphere increases gradually with altitude, ranging up to around near the top. In the upper part of the chromosphere helium becomes partially ionized.


title: Sun

text: Above the chromosphere, in a thin (about ) transition region, the temperature rises rapidly from around in the upper chromosphere to coronal temperatures closer to . The temperature increase is facilitated by the full ionization of helium in the transition region, which significantly reduces radiative cooling of the plasma. The transition region does not occur at a well-defined altitude. Rather, it forms a kind of nimbus around chromospheric features such as spicules and filaments, and is in constant, chaotic motion. The transition region is not easily visible from Earth's surface, but is readily observable from space by instruments sensitive to the extreme ultraviolet portion of the spectrum.


title: Sun

text: The corona is the next layer of the Sun. The low corona, near the surface of the Sun, has a particle density around 10 m to 10 m. The average temperature of the corona and solar wind is about 1,000,000–2,000,000 K; however, in the hottest regions it is 8,000,000–20,000,000 K. Although no complete theory yet exists to account for the temperature of the corona, at least some of its heat is known to be from magnetic reconnection.


title: Sun

text: The corona is the extended atmosphere of the Sun, which has a volume much larger than the volume enclosed by the Sun's photosphere. A flow of plasma outward from the Sun into interplanetary space is the solar wind.


title: Sun

text: The heliosphere, the tenuous outermost atmosphere of the Sun, is filled with the solar wind plasma. This outermost layer of the Sun is defined to begin at the distance where the flow of the solar wind becomes "superalfvénic"—that is, where the flow becomes faster than the speed of Alfvén waves, at approximately 20 solar radii (0.1 AU). Turbulence and dynamic forces in the heliosphere cannot affect the shape of the solar corona within, because the information can only travel at the speed of Alfvén waves. The solar wind travels outward continuously through the heliosphere, forming the solar magnetic field into a spiral shape, until it impacts the heliopause more than from the Sun. In December 2004, the "Voyager 1" probe passed through a shock front that is thought to be part of the heliopause. In late 2012 "Voyager 1" recorded a marked increase in cosmic ray collisions and a sharp drop in lower energy particles from the solar wind, which suggested that the probe had passed through the heliopause and entered the interstellar medium, and indeed did so August 25, 2012 at approximately 122 astronomical units from the Sun. The heliosphere has a heliotail which stretches out behind it due to the Sun's movement.


title: Sun

text: On April 28, 2021, during its eighth flyby of the Sun, NASA's Parker Solar Probe encountered the specific magnetic and particle conditions at 18.8 solar radii that indicated that it penetrated the Alfvén surface, the boundary separating the corona from the solar wind defined as where the coronal plasma's Alfvén speed and the large-scale solar wind speed are equal. The probe measured the solar wind plasma environment with its FIELDS and SWEAP instruments. This event was described by NASA as "touching the Sun". During the flyby, Parker Solar Probe passed into and out of the corona several times. This proved the predictions that the Alfvén critical surface isn't shaped like a smooth ball, but has spikes and valleys that wrinkle its surface.


title: Sun

text: The Sun emits light across the visible spectrum, so its color is white, with a CIE color-space index near (0.3, 0.3), when viewed from space or when the Sun is high in the sky. The Solar radiance per wavelength peaks in the green portion of the spectrum when viewed from space. When the Sun is very low in the sky, atmospheric scattering renders the Sun yellow, red, orange, or magenta, and in rare occasions even green or blue. Despite its typical whiteness (white sunrays, white ambient light, white illumination of the Moon, etc.), some cultures mentally picture the Sun as yellow and some even red; the reasons for this are cultural and exact ones are the subject of debate.


title: Sun

text: The Sun is a G2V star, with "G2" indicating its surface temperature of approximately , and "V" that it, like most stars, is a main-sequence star.


title: Sun

text: The solar constant is the amount of power that the Sun deposits per unit area that is directly exposed to sunlight. The solar constant is equal to approximately (watts per square meter) at a distance of one astronomical unit (AU) from the Sun (that is, on or near Earth). Sunlight on the surface of Earth is attenuated by Earth's atmosphere, so that less power arrives at the surface (closer to ) in clear conditions when the Sun is near the zenith. Sunlight at the top of Earth's atmosphere is composed (by total energy) of about 50% infrared light, 40% visible light, and 10% ultraviolet light. The atmosphere in particular filters out over 70% of solar ultraviolet, especially at the shorter wavelengths. Solar ultraviolet radiation ionizes Earth's dayside upper atmosphere, creating the electrically conducting ionosphere.


title: Sun

text: Ultraviolet light from the Sun has antiseptic properties and can be used to sanitize tools and water. It also causes sunburn, and has other biological effects such as the production of vitamin D and sun tanning. It is also the main cause of skin cancer. Ultraviolet light is strongly attenuated by Earth's ozone layer, so that the amount of UV varies greatly with latitude and has been partially responsible for many biological adaptations, including variations in human skin color in different regions of the Earth.High-energy gamma ray photons initially released with fusion reactions in the core are almost immediately absorbed by the solar plasma of the radiative zone, usually after traveling only a few millimeters. Re-emission happens in a random direction and usually at slightly lower energy. With this sequence of emissions and absorptions, it takes a long time for radiation to reach the Sun's surface. Estimates of the photon travel time range between 10,000 and 170,000 years. In contrast, it takes only 2.3 seconds for the neutrinos, which account for about 2% of the total energy production of the Sun, to reach the surface. Because energy transport in the Sun is a process that involves photons in thermodynamic equilibrium with matter, the time scale of energy transport in the Sun is longer, on the order of 30,000,000 years. This is the time it would take the Sun to return to a stable state if the rate of energy generation in its core were suddenly changed.


title: Sun

text: Neutrinos are also released by the fusion reactions in the core, but, unlike photons, they rarely interact with matter, so almost all are able to escape the Sun immediately. For many years measurements of the number of neutrinos produced in the Sun were lower than theories predicted by a factor of 3. This discrepancy was resolved in 2001 through the discovery of the effects of neutrino oscillation: the Sun emits the number of neutrinos predicted by the theory, but neutrino detectors were missing of them because the neutrinos had changed flavor by the time they were detected.


title: Sun

text: The Sun has a stellar magnetic field that varies across its surface. Its polar field is , whereas the field is typically in features on the Sun called sunspots and in solar prominences. The magnetic field varies in time and location. The quasi-periodic 11-year solar cycle is the most prominent variation in which the number and size of sunspots waxes and wanes.<ref name="doi10.1146/annurev-astro-081913-040012"></ref>


title: Sun

text: The solar magnetic field extends well beyond the Sun itself. The electrically conducting solar wind plasma carries the Sun's magnetic field into space, forming what is called the interplanetary magnetic field. In an approximation known as ideal magnetohydrodynamics, plasma particles only move along the magnetic field lines. As a result, the outward-flowing solar wind stretches the interplanetary magnetic field outward, forcing it into a roughly radial structure. For a simple dipolar solar magnetic field, with opposite hemispherical polarities on either side of the solar magnetic equator, a thin current sheet is formed in the solar wind.


title: Sun

text: At great distances, the rotation of the Sun twists the dipolar magnetic field and corresponding current sheet into an Archimedean spiral structure called the Parker spiral. The interplanetary magnetic field is much stronger than the dipole component of the solar magnetic field. The Sun's dipole magnetic field of 50–400 μT (at the photosphere) reduces with the inverse-cube of the distance, leading to a predicted magnetic field of 0.1 nT at the distance of Earth. However, according to spacecraft observations the interplanetary field at Earth's location is around 5 nT, about a hundred times greater. The difference is due to magnetic fields generated by electrical currents in the plasma surrounding the Sun.


title: Sun

text: Sunspots are visible as dark patches on the Sun's photosphere and correspond to concentrations of magnetic field where the convective transport of heat is inhibited from the solar interior to the surface. As a result, sunspots are slightly cooler than the surrounding photosphere, so they appear dark. At a typical solar minimum, few sunspots are visible, and occasionally none can be seen at all. Those that do appear are at high solar latitudes. As the solar cycle progresses towards its maximum, sunspots tend to form closer to the solar equator, a phenomenon known as Spörer's law. The largest sunspots can be tens of thousands of kilometers across.


title: Sun

text: An 11-year sunspot cycle is half of a 22-year Babcock–Leighton dynamo cycle, which corresponds to an oscillatory exchange of energy between toroidal and poloidal solar magnetic fields. At solar-cycle maximum, the external poloidal dipolar magnetic field is near its dynamo-cycle minimum strength, but an internal toroidal quadrupolar field, generated through differential rotation within the tachocline, is near its maximum strength. At this point in the dynamo cycle, buoyant upwelling within the convective zone forces emergence of the toroidal magnetic field through the photosphere, giving rise to pairs of sunspots, roughly aligned east–west and having footprints with opposite magnetic polarities. The magnetic polarity of sunspot pairs alternates every solar cycle, a phenomenon described by Hale's law.


title: Sun

text: During the solar cycle's declining phase, energy shifts from the internal toroidal magnetic field to the external poloidal field, and sunspots diminish in number and size. At solar-cycle minimum, the toroidal field is, correspondingly, at minimum strength, sunspots are relatively rare, and the poloidal field is at its maximum strength. With the rise of the next 11-year sunspot cycle, differential rotation shifts magnetic energy back from the poloidal to the toroidal field, but with a polarity that is opposite to the previous cycle. The process carries on continuously, and in an idealized, simplified scenario, each 11-year sunspot cycle corresponds to a change, then, in the overall polarity of the Sun's large-scale magnetic field.


title: Sun

text: The Sun's magnetic field leads to many effects that are collectively called solar activity. Solar flares and coronal-mass ejections tend to occur at sunspot groups. Slowly changing high-speed streams of solar wind are emitted from coronal holes at the photospheric surface. Both coronal-mass ejections and high-speed streams of solar wind carry plasma and interplanetary magnetic field outward into the Solar System. The effects of solar activity on Earth include auroras at moderate to high latitudes and the disruption of radio communications and electric power. Solar activity is thought to have played a large role in the formation and evolution of the Solar System.


title: Sun

text: Long-term secular change in sunspot number is thought, by some scientists, to be correlated with long-term change in solar irradiance, which, in turn, might influence Earth's long-term climate. The solar cycle influences space weather conditions, including those surrounding Earth. For example, in the 17th century, the solar cycle appeared to have stopped entirely for several decades; few sunspots were observed during a period known as the Maunder minimum. This coincided in time with the era of the Little Ice Age, when Europe experienced unusually cold temperatures. Earlier extended minima have been discovered through analysis of tree rings and appear to have coincided with lower-than-average global temperatures.


title: Sun

text: In December 2019, a new type of solar magnetic explosion was observed, known as forced magnetic reconnection. Previously, in a process called spontaneous magnetic reconnection, it was observed that the solar magnetic field lines diverge explosively and then converge again instantaneously. Forced Magnetic Reconnection was similar, but it was triggered by an explosion in the corona.


title: Sun

text: The Sun today is roughly halfway through the most stable part of its life. It has not changed dramatically for over four billion years and will remain fairly stable for more than five billion more. However, after hydrogen fusion in its core has stopped, the Sun will undergo dramatic changes, both internally and externally. It is more massive than 71 of 75 other stars within 5 pc, or in the top ~5 percent.


title: Sun

text: The Sun formed about 4.6 billion years ago from the collapse of part of a giant molecular cloud that consisted mostly of hydrogen and helium and that probably gave birth to many other stars. This age is estimated using computer models of stellar evolution and through nucleocosmochronology. The result is consistent with the radiometric date of the oldest Solar System material, at 4.567 billion years ago. Studies of ancient meteorites reveal traces of stable daughter nuclei of short-lived isotopes, such as iron-60, that form only in exploding, short-lived stars. This indicates that one or more supernovae must have occurred near the location where the Sun formed. A shock wave from a nearby supernova would have triggered the formation of the Sun by compressing the matter within the molecular cloud and causing certain regions to collapse under their own gravity. As one fragment of the cloud collapsed it also began to rotate due to conservation of angular momentum and heat up with the increasing pressure. Much of the mass became concentrated in the center, whereas the rest flattened out into a disk that would become the planets and other Solar System bodies. Gravity and pressure within the core of the cloud generated a lot of heat as it accumulated more matter from the surrounding disk, eventually triggering nuclear fusion.


title: Sun

text: The Sun is about halfway through its main-sequence stage, during which nuclear fusion reactions in its core fuse hydrogen into helium. Each second, more than four million tonnes of matter are converted into energy within the Sun's core, producing neutrinos and solar radiation. At this rate, the Sun has so far converted around 100 times the mass of Earth into energy, about 0.03% of the total mass of the Sun. The Sun will spend a total of approximately 10 to 11  billion years as a main-sequence star before the red giant phase of the sun. At the 8 billion year mark, the sun will be at its hottest point according to the ESA's Gaia space observatory mission in 2022.


title: Sun

text: The Sun is gradually becoming hotter in its core, hotter at the surface, larger in radius, and more luminous during its time on the main sequence: since the beginning of its main sequence life, it has expanded in radius by 15% and the surface has increased in temperature from to , resulting in a 48% increase in luminosity from 0.677 solar luminosities to its present-day 1.0 solar luminosity. This occurs because the helium atoms in the core have a higher mean molecular weight than the hydrogen atoms that were fused, resulting in less thermal pressure. The core is therefore shrinking, allowing the outer layers of the Sun to move closer to the center, releasing gravitational potential energy. According to the virial theorem, half this released gravitational energy goes into heating, which leads to a gradual increase in the rate at which fusion occurs and thus an increase in the luminosity. This process speeds up as the core gradually becomes denser. At present, it is increasing in brightness by about 1% every 100 million years. It will take at least 1 billion years from now to deplete liquid water from the Earth from such increase. After that, the Earth will cease to be able to support complex, multicellular life and the last remaining multicellular organisms on the planet will suffer a final, complete mass extinction.


title: Sun

text: The Sun does not have enough mass to explode as a supernova. Instead, when it runs out of hydrogen in the core in approximately 5 billion years, core hydrogen fusion will stop, and there will be nothing to prevent the core from contracting. The release of gravitational potential energy will cause the luminosity of the Sun to increase, ending the main sequence phase and leading the Sun to expand over the next billion years: first into a subgiant, and then into a red giant. The heating due to gravitational contraction will also lead to hydrogen fusion in a shell just outside the core, where unfused hydrogen remains, contributing to the increased luminosity, which will eventually reach more than 1,000 times its present luminosity. When the Sun enters its red-giant branch (RGB) phase, it will engulf Mercury and (likely) Venus, reaching about . The Sun will spend around a billion years in the RGB and lose around a third of its mass.


title: Sun

text: After the red-giant branch, the Sun has approximately 120 million years of active life left, but much happens. First, the core (full of degenerate helium) ignites violently in the helium flash; it is estimated that 6% of the core—itself 40% of the Sun's mass—will be converted into carbon within a matter of minutes through the triple-alpha process. The Sun then shrinks to around 10 times its current size and 50 times the luminosity, with a temperature a little lower than today. It will then have reached the red clump or horizontal branch, but a star of the Sun's metallicity does not evolve blueward along the horizontal branch. Instead, it just becomes moderately larger and more luminous over about 100 million years as it continues to react helium in the core.


title: Sun

text: When the helium is exhausted, the Sun will repeat the expansion it followed when the hydrogen in the core was exhausted. This time, however, it all happens faster, and the Sun becomes larger and more luminous, engulfing Venus if it has not already. This is the asymptotic-giant-branch phase, and the Sun is alternately reacting hydrogen in a shell or helium in a deeper shell. After about 20 million years on the early asymptotic giant branch, the Sun becomes increasingly unstable, with rapid mass loss and thermal pulses that increase the size and luminosity for a few hundred years every 100,000 years or so. The thermal pulses become larger each time, with the later pulses pushing the luminosity to as much as 5,000 times the current level and the radius to over .


title: Sun

text: According to a 2008 model, Earth's orbit will have initially expanded to at most due to the Sun's loss of mass as a red giant. However, Earth's orbit will later start shrinking due to tidal forces (and, eventually, drag from the lower chromosphere) so that it is engulfed by the Sun during the tip of the red-giant branch phase, 3.8 and 1 million years after Mercury and Venus have respectively suffered the same fate. Models vary depending on the rate and timing of mass loss. Models that have higher mass loss on the red-giant branch produce smaller, less luminous stars at the tip of the asymptotic giant branch, perhaps only 2,000 times the luminosity and less than 200 times the radius. For the Sun, four thermal pulses are predicted before it completely loses its outer envelope and starts to make a planetary nebula. By the end of that phase—lasting approximately 500,000 years—the Sun will only have about half of its current mass.


title: Sun

text: The post-asymptotic-giant-branch evolution is even faster. The luminosity stays approximately constant as the temperature increases, with the ejected half of the Sun's mass becoming ionized into a planetary nebula as the exposed core reaches , as if it is in a sort of blue loop. The final naked core, a white dwarf, will have a temperature of over , and contain an estimated 54.05% of the Sun's present-day mass. The planetary nebula will disperse in about 10,000 years, but the white dwarf will survive for trillions of years before fading to a hypothetical black dwarf.


title: Sun

text: The Sun has eight known planets orbiting around it. This includes four terrestrial planets (Mercury, Venus, Earth, and Mars), two gas giants (Jupiter and Saturn), and two ice giants (Uranus and Neptune). The Solar System also has nine bodies generally considered as dwarf planets and some more candidates, an asteroid belt, numerous comets, and a large number of icy bodies which lie beyond the orbit of Neptune. Six of the planets and many smaller bodies also have their own natural satellites: in particular, the satellite systems of Jupiter, Saturn, and Uranus are in some ways like miniature versions of the Sun's system.


title: Sun

text: The Sun is moved by the gravitational pull of the planets. The center of the Sun is always within 2.2 solar radii of the barycenter. This motion of the Sun is mainly due to Jupiter, Saturn, Uranus, and Neptune. For some periods of several decades, the motion is rather regular, forming a trefoil pattern, whereas between these periods it appears more chaotic. After 179 years (nine times the synodic period of Jupiter and Saturn), the pattern more or less repeats, but rotated by about 24°. The orbits of the inner planets, including of the Earth, are similarly displaced by the same gravitational forces, so the movement of the Sun has little effect on the relative positions of the Earth and the Sun or on solar irradiance on the Earth as a function of time.


title: Sun

text: The Sun has been an object of veneration in many cultures throughout human history. Humanity's most fundamental understanding of the Sun is as the luminous disk in the sky, whose presence above the horizon causes day and whose absence causes night. In many prehistoric and ancient cultures, the Sun was thought to be a solar deity or other supernatural entity. The Sun has played an important part in many world religions, as described in a later section.


title: Sun

text: In the early first millennium BC, Babylonian astronomers observed that the Sun's motion along the ecliptic is not uniform, though they did not know why; it is today known that this is due to the movement of Earth in an elliptic orbit around the Sun, with Earth moving faster when it is nearer to the Sun at perihelion and moving slower when it is farther away at aphelion.


title: Sun

text: One of the first people to offer a scientific or philosophical explanation for the Sun was the Greek philosopher Anaxagoras. He reasoned that it was not the chariot of Helios, but instead a giant flaming ball of metal even larger than the land of the Peloponnesus and that the Moon reflected the light of the Sun. For teaching this heresy, he was imprisoned by the authorities and sentenced to death, though he was later released through the intervention of Pericles. Eratosthenes estimated the distance between Earth and the Sun in the third century BC as "of stadia myriads 400 and 80000", the translation of which is ambiguous, implying either 4,080,000 stadia (755,000 km) or 804,000,000 stadia (148 to 153 million kilometers or 0.99 to 1.02 AU); the latter value is correct to within a few percent. In the first century AD, Ptolemy estimated the distance as 1,210 times the radius of Earth, approximately .


title: Sun

text: The theory that the Sun is the center around which the planets orbit was first proposed by the ancient Greek Aristarchus of Samos in the third century BC, and later adopted by Seleucus of Seleucia (see Heliocentrism). This view was developed in a more detailed mathematical model of a heliocentric system in the 16th century by Nicolaus Copernicus.


title: Sun

text: Observations of sunspots were recorded during the Han Dynasty (206 BC–AD 220) by Chinese astronomers, who maintained records of these observations for centuries. Averroes also provided a description of sunspots in the 12th century. The invention of the telescope in the early 17th century permitted detailed observations of sunspots by Thomas Harriot, Galileo Galilei and other astronomers. Galileo posited that sunspots were on the surface of the Sun rather than small objects passing between Earth and the Sun.


title: Sun

text: Arabic astronomical contributions include Al-Battani's discovery that the direction of the Sun's apogee (the place in the Sun's orbit against the fixed stars where it seems to be moving slowest) is changing. (In modern heliocentric terms, this is caused by a gradual motion of the aphelion of the "Earth's" orbit). Ibn Yunus observed more than 10,000 entries for the Sun's position for many years using a large astrolabe.


title: Sun

text: From an observation of a transit of Venus in 1032, the Persian astronomer and polymath Ibn Sina concluded that Venus is closer to Earth than the Sun. In 1672 Giovanni Cassini and Jean Richer determined the distance to Mars and were thereby able to calculate the distance to the Sun.


title: Sun

text: In 1666, Isaac Newton observed the Sun's light using a prism, and showed that it is made up of light of many colors. In 1800, William Herschel discovered infrared radiation beyond the red part of the solar spectrum. The 19th century saw advancement in spectroscopic studies of the Sun; Joseph von Fraunhofer recorded more than 600 absorption lines in the spectrum, the strongest of which are still often referred to as Fraunhofer lines. The 20th century brought about several specialized systems for observing the sun, especially at different narrowband wavelengths, such as those using Calcium H (396.9 nm), K (393.37 nm) and Hydrogen-alpha (656.46 nm) filtering.


title: Sun

text: In the early years of the modern scientific era, the source of the Sun's energy was a significant puzzle. Lord Kelvin suggested that the Sun is a gradually cooling liquid body that is radiating an internal store of heat. Kelvin and Hermann von Helmholtz then proposed a gravitational contraction mechanism to explain the energy output, but the resulting age estimate was only 20 million years, well short of the time span of at least 300 million years suggested by some geological discoveries of that time. In 1890 Joseph Lockyer, who discovered helium in the solar spectrum, proposed a meteoritic hypothesis for the formation and evolution of the Sun.


title: Sun

text: Not until 1904 was a documented solution offered. Ernest Rutherford suggested that the Sun's output could be maintained by an internal source of heat, and suggested radioactive decay as the source. However, it would be Albert Einstein who would provide the essential clue to the source of the Sun's energy output with his mass–energy equivalence relation . In 1920, Sir Arthur Eddington proposed that the pressures and temperatures at the core of the Sun could produce a nuclear fusion reaction that merged hydrogen (protons) into helium nuclei, resulting in a production of energy from the net change in mass. The preponderance of hydrogen in the Sun was confirmed in 1925 by Cecilia Payne using the ionization theory developed by Meghnad Saha. The theoretical concept of fusion was developed in the 1930s by the astrophysicists Subrahmanyan Chandrasekhar and Hans Bethe. Hans Bethe calculated the details of the two main energy-producing nuclear reactions that power the Sun. In 1957, Margaret Burbidge, Geoffrey Burbidge, William Fowler and Fred Hoyle showed that most of the elements in the universe have been synthesized by nuclear reactions inside stars, some like the Sun.


title: Sun

text: The first satellites designed for long term observation of the Sun from interplanetary space were NASA's Pioneers 6, 7, 8 and 9, which were launched between 1959 and 1968. These probes orbited the Sun at a distance similar to that of Earth, and made the first detailed measurements of the solar wind and the solar magnetic field. Pioneer 9 operated for a particularly long time, transmitting data until May 1983.


title: Sun

text: In the 1970s, two Helios spacecraft and the Skylab Apollo Telescope Mount provided scientists with significant new data on solar wind and the solar corona. The Helios 1 and 2 probes were U.S.–German collaborations that studied the solar wind from an orbit carrying the spacecraft inside Mercury's orbit at perihelion. The Skylab space station, launched by NASA in 1973, included a solar observatory module called the Apollo Telescope Mount that was operated by astronauts resident on the station. Skylab made the first time-resolved observations of the solar transition region and of ultraviolet emissions from the solar corona. Discoveries included the first observations of coronal mass ejections, then called "coronal transients", and of coronal holes, now known to be intimately associated with the solar wind.


title: Sun

text: In the 1970s, much research focused on the abundances of iron-group elements in the Sun. Although significant research was done, until 1978 it was difficult to determine the abundances of some iron-group elements (e.g. cobalt and manganese) via spectrography because of their hyperfine structures. The first largely complete set of oscillator strengths of singly ionized iron-group elements were made available in the 1960s, and these were subsequently improved. In 1978, the abundances of singly ionized elements of the iron group were derived.


title: Sun

text: Various authors have considered the existence of a gradient in the isotopic compositions of solar and planetary noble gases, e.g. correlations between isotopic compositions of neon and xenon in the Sun and on the planets. Prior to 1983, it was thought that the whole Sun has the same composition as the solar atmosphere. In 1983, it was claimed that it was fractionation in the Sun itself that caused the isotopic-composition relationship between the planetary and solar-wind-implanted noble gases.


title: Sun

text: In 1980, the Solar Maximum Mission probes was launched by NASA. This spacecraft was designed to observe gamma rays, X-rays and UV radiation from solar flares during a time of high solar activity and solar luminosity. Just a few months after launch, however, an electronics failure caused the probe to go into standby mode, and it spent the next three years in this inactive state. In 1984 Space Shuttle "Challenger" mission STS-41C retrieved the satellite and repaired its electronics before re-releasing it into orbit. The Solar Maximum Mission subsequently acquired thousands of images of the solar corona before re-entering Earth's atmosphere in June 1989.


title: Sun

text: Launched in 1991, Japan's Yohkoh ("Sunbeam") satellite observed solar flares at X-ray wavelengths. Mission data allowed scientists to identify several different types of flares and demonstrated that the corona away from regions of peak activity was much more dynamic and active than had previously been supposed. Yohkoh observed an entire solar cycle but went into standby mode when an annular eclipse in 2001 caused it to lose its lock on the Sun. It was destroyed by atmospheric re-entry in 2005.


title: Sun

text: One of the most important solar missions to date has been the Solar and Heliospheric Observatory, jointly built by the European Space Agency and NASA and launched on 2 December 1995. Originally intended to serve a two-year mission, a mission extension through 2012 was approved in October 2009. It has proven so useful that a follow-on mission, the Solar Dynamics Observatory, was launched in February 2010. Situated at the Lagrangian point between Earth and the Sun (at which the gravitational pull from both is equal), SOHO has provided a constant view of the Sun at many wavelengths since its launch. Besides its direct solar observation, SOHO has enabled the discovery of a large number of comets, mostly tiny sungrazing comets that incinerate as they pass the Sun.


title: Sun

text: All these satellites have observed the Sun from the plane of the ecliptic, and so have only observed its equatorial regions in detail. The "Ulysses" probe was launched in 1990 to study the Sun's polar regions. It first traveled to Jupiter, to "slingshot" into an orbit that would take it far above the plane of the ecliptic. Once "Ulysses" was in its scheduled orbit, it began observing the solar wind and magnetic field strength at high solar latitudes, finding that the solar wind from high latitudes was moving at about 750 km/s, which was slower than expected, and that there were large magnetic waves emerging from high latitudes that scattered galactic cosmic rays.


title: Sun

text: Elemental abundances in the photosphere are well known from spectroscopic studies, but the composition of the interior of the Sun is more poorly understood. A solar wind sample return mission, "Genesis", was designed to allow astronomers to directly measure the composition of solar material.


title: Sun

text: The temperature of the photosphere is approximately 6,000 K, whereas the temperature of the corona reaches . The high temperature of the corona shows that it is heated by something other than direct heat conduction from the photosphere.


title: Sun

text: It is thought that the energy necessary to heat the corona is provided by turbulent motion in the convection zone below the photosphere, and two main mechanisms have been proposed to explain coronal heating. The first is wave heating, in which sound, gravitational or magnetohydrodynamic waves are produced by turbulence in the convection zone. These waves travel upward and dissipate in the corona, depositing their energy in the ambient matter in the form of heat. The other is magnetic heating, in which magnetic energy is continuously built up by photospheric motion and released through magnetic reconnection in the form of large solar flares and myriad similar but smaller events—nanoflares.


title: Sun

text: Currently, it is unclear whether waves are an efficient heating mechanism. All waves except Alfvén waves have been found to dissipate or refract before reaching the corona. In addition, Alfvén waves do not easily dissipate in the corona. Current research focus has therefore shifted towards flare heating mechanisms.


title: Sun

text: Theoretical models of the Sun's development suggest that 3.8 to 2.5 billion years ago, during the Archean eon, the Sun was only about 75% as bright as it is today. Such a weak star would not have been able to sustain liquid water on Earth's surface, and thus life should not have been able to develop. However, the geological record demonstrates that Earth has remained at a fairly constant temperature throughout its history and that the young Earth was somewhat warmer than it is today. One theory among scientists is that the atmosphere of the young Earth contained much larger quantities of greenhouse gases (such as carbon dioxide, methane) than are present today, which trapped enough heat to compensate for the smaller amount of solar energy reaching it.


title: Sun

text: However, examination of Archaean sediments appears inconsistent with the hypothesis of high greenhouse concentrations. Instead, the moderate temperature range may be explained by a lower surface albedo brought about by less continental area and the lack of biologically induced cloud condensation nuclei. This would have led to increased absorption of solar energy, thereby compensating for the lower solar output.


title: Sun

text: The brightness of the Sun can cause pain from looking at it with the naked eye; however, doing so for brief periods is not hazardous for normal non-dilated eyes. Looking directly at the Sun (sungazing) causes phosphene visual artifacts and temporary partial blindness. It also delivers about 4 milliwatts of sunlight to the retina, slightly heating it and potentially causing damage in eyes that cannot respond properly to the brightness. Long-duration viewing of the direct Sun with the naked eye can begin to cause UV-induced, sunburn-like lesions on the retina after about 100 seconds, particularly under conditions where the UV light from the Sun is intense and well focused.


title: Sun

text: Viewing the Sun through light-concentrating optics such as binoculars may result in permanent damage to the retina without an appropriate filter that blocks UV and substantially dims the sunlight. When using an attenuating filter to view the Sun, the viewer is cautioned to use a filter specifically designed for that use. Some improvised filters that pass UV or IR rays, can actually harm the eye at high brightness levels. Brief glances at the midday Sun through an unfiltered telescope can cause permanent damage.


title: Sun

text: During sunrise and sunset, sunlight is attenuated because of Rayleigh scattering and Mie scattering from a particularly long passage through Earth's atmosphere, and the Sun is sometimes faint enough to be viewed comfortably with the naked eye or safely with optics (provided there is no risk of bright sunlight suddenly appearing through a break between clouds). Hazy conditions, atmospheric dust, and high humidity contribute to this atmospheric attenuation.


title: Sun

text: An optical phenomenon, known as a green flash, can sometimes be seen shortly after sunset or before sunrise. The flash is caused by light from the Sun just below the horizon being bent (usually through a temperature inversion) towards the observer. Light of shorter wavelengths (violet, blue, green) is bent more than that of longer wavelengths (yellow, orange, red) but the violet and blue light is scattered more, leaving light that is perceived as green.


title: Sun

text: Solar deities play a major role in many world religions and mythologies. Worship of the Sun was central to civilizations such as the ancient Egyptians, the Inca of South America and the Aztecs of what is now Mexico. In religions such as Hinduism, the Sun is still considered a god, he is known as Surya Dev. Many ancient monuments were constructed with solar phenomena in mind; for example, stone megaliths accurately mark the summer or winter solstice (some of the most prominent megaliths are located in Nabta Playa, Egypt; Mnajdra, Malta and at Stonehenge, England); Newgrange, a prehistoric human-built mount in Ireland, was designed to detect the winter solstice; the pyramid of El Castillo at Chichén Itzá in Mexico is designed to cast shadows in the shape of serpents climbing the pyramid at the vernal and autumnal equinoxes.


title: Sun

text: The ancient Sumerians believed that the Sun was Utu, the god of justice and twin brother of Inanna, the Queen of Heaven, who was identified as the planet Venus. Later, Utu was identified with the East Semitic god Shamash. Utu was regarded as a helper-deity, who aided those in distress, and, in iconography, he is usually portrayed with a long beard and clutching a saw, which represented his role as the dispenser of justice.


title: Sun

text: From at least the Fourth Dynasty of Ancient Egypt, the Sun was worshipped as the god Ra, portrayed as a falcon-headed divinity surmounted by the solar disk, and surrounded by a serpent. In the New Empire period, the Sun became identified with the dung beetle, whose spherical ball of dung was identified with the Sun. In the form of the sun disc Aten, the Sun had a brief resurgence during the Amarna Period when it again became the preeminent, if not only, divinity for the Pharaoh Akhenaton.


title: Sun

text: The Egyptians portrayed the god Ra as being carried across the sky in a solar barque, accompanied by lesser gods, and to the Greeks, he was Helios, carried by a chariot drawn by fiery horses. From the reign of Elagabalus in the late Roman Empire the Sun's birthday was a holiday celebrated as Sol Invictus (literally "Unconquered Sun") soon after the winter solstice, which may have been an antecedent to Christmas. Regarding the fixed stars, the Sun appears from Earth to revolve once a year along the ecliptic through the zodiac, and so Greek astronomers categorized it as one of the seven planets (Greek "planetes", "wanderer"); the naming of the days of the weeks after the seven planets dates to the Roman era.


title: Sun

text: In Proto-Indo-European religion, the Sun was personified as the goddess "*Sehul". Derivatives of this goddess in Indo-European languages include the Old Norse "Sól", Sanskrit "Surya", Gaulish "Sulis", Lithuanian "Saulė", and Slavic "Solntse". In ancient Greek religion, the sun deity was the male god Helios, who in later times was syncretized with Apollo.


title: Sun

text: In the Bible, mentions the "Sun of Righteousness" (sometimes translated as the "Sun of Justice"), which some Christians have interpreted as a reference to the Messiah (Christ). In ancient Roman culture, Sunday was the day of the sun god. It was adopted as the Sabbath day by Christians who did not have a Jewish background. The symbol of light was a pagan device adopted by Christians, and perhaps the most important one that did not come from Jewish traditions. In paganism, the Sun was a source of life, giving warmth and illumination to mankind. It was the center of a popular cult among Romans, who would stand at dawn to catch the first rays of sunshine as they prayed. The celebration of the winter solstice (which influenced Christmas) was part of the Roman cult of the unconquered Sun (Sol Invictus). Christian churches were built with an orientation so that the congregation faced toward the sunrise in the East.


title: Sun

text: Tonatiuh, the Aztec god of the sun, was usually depicted holding arrows and a shield and was closely associated with the practice of human sacrifice. The sun goddess Amaterasu is the most important deity in the Shinto religion, and she is believed to be the direct ancestor of all Japanese emperors.


title: Ron Howard

text: Ronald William Howard (born March 1, 1954) is an American director, producer, screenwriter, and actor. He first came to prominence as a child actor, guest-starring in several television series, including an episode of "The Twilight Zone". He gained national attention for playing young Opie Taylor, the son of Sheriff Andy Taylor (played by Andy Griffith) in the sitcom "The Andy Griffith Show" from 1960 through 1968. During this time, he also appeared in the musical film "The Music Man" (1962), a critical and commercial success. He was credited as Ronny Howard in his film and television appearances from 1959 to 1973. Howard was cast in one of the lead roles in the coming-of-age film "American Graffiti" (1973), and became a household name for playing Richie Cunningham in the sitcom "Happy Days", a role he would play from 1974 to 1980.


title: Ron Howard

text: In 1980, Howard left "Happy Days" to focus on directing, producing and sometimes writing a variety of films and television series. His films included the comedies "Night Shift" (1982), "Splash" (1984), and "Cocoon" (1985) as well as the fantasy "Willow" (1988), the thriller "Backdraft" (1991), and the newspaper comedy-drama film "The Paper" (1994). In 1995, Howard gained widespread praise and recognition in the historical docudrama "Apollo 13" (1995). He continued directing such films as the biographical drama "A Beautiful Mind" (2001), the biographical sports drama "Cinderella Man" (2005), the historical drama "Frost/Nixon" (2008), the biographical sports drama "Rush" (2013), and the historical adventure film "In the Heart of the Sea" (2015). Howard is also known for directing the children's fantasy film "How the Grinch Stole Christmas" (2000) as well as the Robert Langdon film series, "The Da Vinci Code" (2006), "Angels & Demons" (2009), "Inferno" (2016), and "" (2018). He has also directed the documentary films "" (2016) and "Pavarotti" (2019).


title: Ron Howard

text: Howard received the Academy Award for Best Director and Academy Award for Best Picture for "A Beautiful Mind" and was nominated again for the same awards for "Frost/Nixon". In 2003, he was awarded the National Medal of Arts. He was inducted into the Television Hall of Fame in 2013. Howard has two stars on the Hollywood Walk of Fame for his contributions in the television and motion pictures industries.


title: Ron Howard

text: Ron Howard was born on March 1, 1954, in Duncan, Oklahoma, the elder son of Jean Speegle, an actress, and Rance Howard, a director, writer, and actor. He has German, English, Scottish, Irish, and Dutch ancestry. His father was born with the surname "Beckenholdt" and took the stage name "Howard" in 1948 for his acting career. Rance Howard was serving three years in the United States Air Force at the time of Ron's birth. The family moved to Hollywood in 1958, the year before the birth of his younger brother Clint Howard. They rented a house on the block south of the Desilu Studios, where "The Andy Griffith Show" was later filmed. They lived in Hollywood for at least three years, before moving to Burbank.


title: Ron Howard

text: Howard was tutored at Desilu Studios in his younger years but continued his schooling at Robert Louis Stevenson Elementary and David Star Jordan Junior High when not working in television, eventually graduating from John Burroughs High School. He later attended the University of Southern California's School of Cinematic Arts but did not graduate.


title: Ron Howard

text: Howard has said he knew from a young age he might want to go into directing, thanks to his early experience as an actor.


title: Ron Howard

text: In 1959, Howard had his first credited film role in "The Journey". He appeared in June Allyson's CBS anthology series "The DuPont Show with June Allyson" in the episode "Child Lost"; in "The Twilight Zone" episode "Walking Distance"; a few episodes of the first season of the sitcom "Dennis the Menace", as Stewart, one of Dennis's friends; and several first- and second-season episodes of "The Many Loves of Dobie Gillis". Howard played "Timmy" (uncredited) in "Counterfeit Gun", Season 4, Episode 2 (1960) of the TV series, "The Cheyenne Show".


title: Ron Howard

text: In 1960, Howard was cast as Opie Taylor in "The Andy Griffith Show". Credited as "Ronny Howard," he portrayed the son of the title character (played by Andy Griffith) for all eight seasons of the show. Recalling his experiences as a child actor on set, he commented


title: Ron Howard

text: In the 1962 film version of "The Music Man", Howard played Winthrop Paroo, the child with the lisp; the film starred Robert Preston and Shirley Jones. He also starred in the 1963 film "The Courtship of Eddie's Father" with Glenn Ford and Jones.


title: Ron Howard

text: He appeared as Barry Stewart on "The Eleventh Hour" in 1965; on "I Spy" in the 1966 episode "Little Boy Lost"; as Henry Fonda's son in an ABC series, "The Smith Family", in 1968; as Jodah in "Land of the Giants" in 1969; as a boy whose father was shot on "Daniel Boone" in 1971–72; and as an underage Marine on "M*A*S*H" in the episode "Sometimes You Hear the Bullet" in 1973. In the 1970s, he appeared in at least one episode of "The Bold Ones", as a teenage tennis player with an illness.


title: Ron Howard

text: Howard appeared on the 1969 Disneyland Records album "The Story and Song from the Haunted Mansion". It featured the story of two teenagers, Mike (Howard) and Karen (Robie Lester), who get trapped inside the Haunted Mansion. Thurl Ravenscroft plays the Narrator, Pete Reneday plays the Ghost Host, and Eleanor Audley plays Madame Leota. Some of the effects and ideas that were planned but never permanently made it to the attraction are mentioned here: the Raven speaks in the Stretching Room, and the Hatbox Ghost is mentioned during the Attic scene. It was reissued in 1998 as a cassette tape titled "A Spooky Night in Disney's Haunted Mansion" and on CD in 2009.


title: Ron Howard

text: Howard played Steve Bolander in George Lucas' coming-of-age film "American Graffiti" in 1973, which was the inspiration for the television series "Happy Days" starring Howard.


title: Ron Howard

text: In 1974, Howard guest-starred as Seth Turner, the best friend of Jason Walton (Jon Walmsley), in "The Waltons" episode, "The Gift". Featured in the cast as Dr. McIvers is Ron Howard's father Rance Howard.


title: Ron Howard

text: In 1976, Howard starred alongside John Wayne and Lauren Bacall in Don Siegel's "The Shootist", the story of a Western gunfighter dying of cancer. The movie was Wayne's last although it's not true that he had cancer during the shooting of the picture; Wayne died three years later.


title: Ron Howard

text: A role in an installment of series "Love, American Style", titled "Love and the Television Set", led to his being cast as Richie Cunningham in the TV series "Happy Days" (for syndication, the segment was re-titled "Love and the Happy Days"). Beginning in 1974, he played the likeable "buttoned-down" boy, in contrast to Henry Winkler's "greaser" Arthur "Fonzie"/"The Fonz" Fonzarelli. On the "Happy Days" set, he developed an on- and off-screen chemistry with Winkler. Howard left "Happy Days" to become a film director just before the start of its eighth season in 1980, but returned for guest appearances in later seasons.


title: Ron Howard

text: Before leaving "Happy Days" in 1980, Howard made his directing debut with the 1977 low-budget comedy/action film "Grand Theft Auto", based on a script he co-wrote with his father, Rance. This came after cutting a deal with Roger Corman, wherein Corman let Howard direct a film in exchange for Howard starring in "Eat My Dust!", with Christopher Norris. Howard went on to direct several TV movies for NBC between 1978 and 1982, including the 1980 TV movie, "Skyward", starring Bette Davis. His big directorial break came in 1982, with "Night Shift", featuring Michael Keaton, Shelley Long, and Howard's "Happy Days" co-star Henry Winkler.


title: Ron Howard

text: Following "Night Shift", Howard directed a number of major films, including the fantasy romantic comedy "Splash" (1984) starring Tom Hanks, Daryl Hannah, Eugene Levy, and John Candy. The film was a box office and critical success. He also directed the science fiction comedy drama "Cocoon" (1985) starring Don Ameche, Hume Cronyn, Wilford Brimley, and Brian Dennehy. This film was also a critical and financial hit. In 1988, he directed the dark fantasy drama film "Willow" starring Val Kilmer and Warwick Davis. Howard's final work as a director for the 1980s was the family comedy film "Parenthood" (1989) starring an ensemble cast that includes Steve Martin, Tom Hulce, Rick Moranis, Martha Plimpton, Joaquin Phoenix, Keanu Reeves, Jason Robards, Mary Steenburgen, and Dianne Wiest. The film opened at in its opening weekend, earning $10million. It eventually grossed over $100million domestically and $126million worldwide. The film was a critical hit and received two Academy Award nominations.


title: Ron Howard

text: Howard continued directing through the 1990s, including the American drama "Backdraft" revolving around firefighters. The film starred Kurt Russell, Donald Sutherland, and Robert De Niro. Film critics Gene Siskel of the "Chicago Tribune" and Roger Ebert of the "Chicago Sun-Times" gave the film a positive review.


title: Ron Howard

text: In 1992, he directed the western film epic "Far and Away" starring Tom Cruise and Nicole Kidman. Despite receiving mixed reviews from critics the film was a financial success earning 137 million against its budget of 60 million. In 1994, Howard directed the newspaper comedy drama "The Paper" with an ensemble starring Michael Keaton, Glenn Close, Marisa Tomei, Jason Alexander, Jason Robards, and Robert Duvall. The film received rave reviews with many praising Keaton's leading performance.


title: Ron Howard

text: Howard's direction for the 1995 docudrama film "Apollo 13" received praise from critics. The film stars Tom Hanks, Kevin Bacon, and Bill Paxton as the three astronauts members of the Apollo 13 flight crew, with supporting performances from Gary Sinise, Ed Harris, and Kathleen Quinlan. The film was a massive financial success earning $335 million off a budget of $52 million. The film received widespread critical acclaim with Roger Ebert of the "Chicago Sun-Times" praised the film in his review saying: "A powerful story, one of the year's best films, told with great clarity and remarkable technical detail, and acted without pumped-up histrionics." The film went on to receive nine Academy Award nominations including Best Picture.


title: Ron Howard

text: In 2000, he directed the live action children's fantasy film, "How the Grinch Stole Christmas" based on the Dr. Seuss children's book. The film starred Jim Carrey as the titular character and featured performances from Jeffrey Tambor, Christine Baranski, and Molly Shannon, with Anthony Hopkins serving as the film's narrator. Despite the film receiving mixed reviews from critics, it was a financial success and earned $345 million at the box office.


title: Ron Howard

text: Howard's followup film was the biographical drama film "A Beautiful Mind" starring Russell Crowe as the American mathematician John Nash who struggled with paranoid schizophrenia. The film featured performances from Jennifer Connelly, Ed Harris, Josh Lucas, and Christopher Plummer. The film received positive reviews from critics who praised Crowe's and Connelly's performances. The film went on to receive eight Academy Award nominations including a win for Best Picture and a nomination and win for Howard as Best Director.


title: Ron Howard

text: In 2005, Howard directed the biographical sports drama "Cinderella Man" based on the true story of heavyweight boxing champion James J. Braddock played by Russell Crowe. The film also starred Renée Zellweger as his wife Mae Braddock, and Paul Giamatti as his trainer Joe Gould. Rotten Tomatoes gave it an approval rating of 80% based on reviews from 214 critics with an average score of 7.4/10. Its consensus states, "With grittiness and an evocative sense of time and place, "Cinderella Man" is a powerful underdog story. And Ron Howard and Russell Crowe prove to be a solid combination."


title: Ron Howard

text: Howard is also known for directing the Robert Langdon films. The series began with "The Da Vinci Code" (2006) with Tom Hanks as Langdon, featuring performances by Audrey Tautou, Ian McKellen, and Alfred Molina. The sequel was "Angels & Demons" (2009) with Hanks reprising his role and performances by Ewan McGregor and Stellan Skarsgård. In 2016, "Inferno" was released with Hanks continuing the role with performances by Felicity Jones, Irrfan Khan, and Omar Sy. All three films received mixed reviews but were popular among audiences.


title: Ron Howard

text: Howard showcased the world premiere of his historical drama film "Frost/Nixon" at the London Film Festival in October 2008. The film is based on the taped conversations known as the Frost/Nixon interviews between former United States President Richard Nixon and British talk show host David Frost. Frank Langella portrayed Nixon opposite Michael Sheen as Frost. The film was based on the play of the same name by Peter Morgan. The film also featured performances from Mathew Macfadyen, Sam Rockwell, Rebecca Hall, Oliver Platt, Toby Jones, and Kevin Bacon. Despite losing money at the box office, the film was a critical success with website Rotten Tomatoes giving the film an approval rating of 93% with the critical consensus reading, ""Frost/Nixon" is weighty and eloquent; a cross between a boxing match and a ballet with Oscar worthy performances." Metacritic gives the film an average score of 80 out of 100, based on 38 critics, indicating "generally favorable reviews". The film received 5 Academy Award nominations with Howard receiving a nomination for Best Director.


title: Ron Howard

text: Howard was the recipient of the Austin Film Festival's 2009 Extraordinary Contribution to Filmmaking Award. Michael Keaton presented him with the Award.


title: Ron Howard

text: In 2013, Howard directed sports drama "Rush", based on the Hunt–Lauda rivalry between two Formula One drivers, the British James Hunt and the Austrian Niki Lauda during the 1976 Formula 1 motor-racing season. It was written by Peter Morgan and starred Chris Hemsworth as Hunt, Daniel Brühl as Lauda, and Olivia Wilde as Suzy Miller. The film premiered at the 2013 Toronto International Film Festival and received positive reviews from critics.


title: Ron Howard

text: In 2015, Howard directed the film "In the Heart of the Sea" about the sinking of the American whaling ship Essex in 1820, an event that inspired Herman Melville's 1851 novel "Moby-Dick". The film featured performances by Chris Hemsworth, Cillian Murphy, Tom Holland, Ben Whishaw, and Brendan Gleeson. The film was a financial failure and received mixed reviews.


title: Ron Howard

text: Howard took over directing duties on "", a film featuring "Star Wars" character Han Solo in his younger years. The film was released on May 23, 2018. Howard officially replaced directors Phil Lord and Christopher Miller on June 22, 2017; they were let go from their position two days earlier, reportedly due to their refusal to compromise with Lucasfilm over the direction of the film; reportedly the directors encouraged significant improvisations by the actors, which was believed by some at Lucasfilm to be "shifting the story off-course". At the time, the film was nearly completed, with three and a half weeks left to film and another five weeks of reshoots scheduled. Howard posted on Twitter, "I'm beyond grateful to add my voice to the "Star Wars" Universe after being a fan since 5/25/77. I hope to honor the great work already done & help deliver on the promise of a Han Solo film."


title: Ron Howard

text: On November 24, 2020, Howard's drama film "Hillbilly Elegy" was released on Netflix. The film is based on the memoir of the same name by J. D. Vance and was adapted for the screen by Vanessa Taylor. The film stars Academy Award nominees Glenn Close and Amy Adams. The film has received widespread negative reception from critics but was received well by general audiences, with an 83% user approval on Rotten Tomatoes.


title: Ron Howard

text: In March 2021, Howard began filming the survival drama "Thirteen Lives", a film based on the Tham Luang cave rescue in 2018. It was released in select theaters on July 29, 2022, by United Artists Releasing, and began streaming on Prime Video on August 5, 2022. The film received generally positive reviews from critics.


title: Ron Howard

text: Howard is the co-chairman, with Brian Grazer, of Imagine Entertainment, a film and television production company. Imagine has produced several films including "Friday Night Lights", "8 Mile", and "Inside Deep Throat", as well as the television series "24", "Felicity", "The PJs" and "Arrested Development" which Howard also narrated and later appeared in as himself.


title: Ron Howard

text: In July 2012, it was announced that Imagine had put into development "Conquest" for Showtime, a period drama based on the 16th century conquest of the Aztecs by Spanish Conquistadors. To be directed by Howard, the series was originally planned as a feature film before it was decided that the project was more suited to television.


title: Ron Howard

text: As part of Imagine Entertainment, he appeared in a 1997 print ad for Milk – Where's "your" mustache?, in which he wore a cap for Imagine Entertainment and sported a milk mustache. Earlier versions show a younger Ronny Howard on the other side.


title: Ron Howard

text: Howard married his high school sweetheart, Cheryl Alley (born December 23, 1953), a writer, on June 7, 1975. They have four children: daughters Bryce Dallas (born March 2, 1981), twins Jocelyn Carlyle and Paige Carlyle (born February 5, 1985), and son Reed Cross (born April 13, 1987).


title: Philip Seymour Hoffman

text: Philip Seymour Hoffman (July 23, 1967 – February 2, 2014) was an American actor. Known for his distinctive supporting and character roles—typically lowlifes, eccentrics, underdogs, and misfits—he acted in many films and theatrical productions, including leading roles, from the early 1990s until his death in 2014.