Image caption Esa's Herschel Space Observatory captured Apophis in its field of view in the far-infrared light in January 2013 
 
 A 300 metre-wide asteroid is making a close pass to the Earth. 
 
 Apophis - named after the Egyptian demon of destruction and darkness - has been put on a watch list by scientists. 
 
 They have calculated that in 2036 there is a very small chance it could collide with our planet. 
 
 However, its current fly-by is at a safe distance of about 14 million km - but this is close enough for astronomers to study the space rock and assess its future risk. 
 
 Apophis will not be visible with the naked eye, but space enthusiasts can watch it online via the Slooh space camera's website. 
 
 Collision course? 
 
 The large rocky mass was first discovered in 2004. At the time, it raised alarm when scientists calculated that it had a one-in-45 chance of smashing into the Earth in 2029. 
 
 At some point, we are going to find an asteroid big enough that it could cause damage at ground level if we let it hit Prof Alan Fitzsimmons, Queen's University Belfast 
 
 Later revisions, lifted this threat; instead on the Friday 13 April 2029, it will make a close pass at a distance of about 30,000km. 
 
 However, astronomers say there is still a one-in-200,000 chance that it could strike Earth in 2036. 
 
 Professor Alan Fitzsimmons, an astronomer at Queen's University Belfast, UK, said: "In 2029, it will pass so close to us that Earth's gravity will change its orbit. 
 
 "Most of the potential orbits it will end up on will mean we are safe for the next 100 years. But there is a small region of space - something we call a keyhole - and if it passes through that keyhole in 2029, it will come back and hit us on 13 April in 2036." 
 
 If this happened, it would strike the Earth with 100 times the energy in our largest nuclear bombs, said Prof Fitzsimmons. 
 
 Future hazards 
 
 Astronomers are using the current close encounter as an opportunity to study the asteroid, so they can improve their calculations to predict its future path. 
 
 Prof Fitzsimmons said: "While [the asteroid] is relatively close to the Earth, astronomers can ping it with radar. Radar measurements are incredibly accurate: we get the distance to the asteroid very, very precisely, and we can also get its velocity relative to us. And these two things let us pin its orbit down very precisely. " 
 
 Researchers are becoming increasingly interested in potentially hazardous asteroids. 
 
 So far they have counted more than 9,000 near-Earth asteroids, and they spot another 800 new space rocks on average each year. 
 
 Prof Fitzsimmons said learning more about them was vital. 
 
 "At some point, we are going to find an asteroid big enough that it could cause damage at ground level if we let it hit," he explained. 
 
 "So we should find these objects, we should track them, work out where they are going - and if they stand a chance of hitting us, do something about it." ||||| ESA’s Herschel Space Observatory captured asteroid Apophis in its field of view during the approach to Earth on January, 5-6, 2013. This image shows the asteroid in Herschel’s three PACS wavelengths: 70, 100 and 160 microns. 
 
 Credit: ESA/Herschel/PACS/MACH-11/MPE/B.Altieri (ESAC) and C. Kiss (Konkoly Observatory) View full size image 
 
 A European space telescope has captured new images of the huge asteroid Apophis, revealing that the potentially hazardous object is actually bigger than previously thought — and you have a chance to see the space rock yourself in two free webcasts tonight (Jan. 9). 
 
 Asteroid Apophis has long been billed as a "doomsday asteroid" because of a 2004 study that predicted a 2.7 percent chance of the space rock hitting Earth when it passes within 22,364 miles (36,000 kilometers) of the planet in April 2029, European Space Agency officials said. Later studies proved, however, that the asteroid poses no threat to Earth during that flyby, but astronomers continue to track the object since it will make another pass near Earth in 2036. 
 
 At about 36 hours from the minimum distance (9.3 million miles or 15 million kilometers from Earth), potentially hazardous asteroid Apophis was imaged again with the Virtual Telescope, on Jan. 8, 2013. 
 
 Credit: G. Masi & F. Nocentini View full size image At about 36 hours from the minimum distance (9.3 million miles or 15 million kilometers from Earth), potentially hazardous asteroid Apophis was imaged again with the Virtual Telescope, on Jan. 8, 2013. 
 
 Today, ESA officials announced that its infrared Herschel Space Observatory has discovered that Apophis is about 1,066 feet (325 meters) wide, nearly 20 percent larger than a previous estimate of 885 feet (270 m). 
 
 "The 20 percent increase in diameter … translates into a 75 percent increase in our estimates of the asteroid's volume or mass," study leader Thomas Müller of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, said in a statement. [Photos of Near-Earth Asteroid Apophis] 
 
 Tonight's two free webcasts will stream live views of Apophis from telescopes in Italy and the Canary Islands tonight (Jan. 10). The webcasts, offered by the stargazing websites Slooh Space Telescope and Virtual Telescope Project, will show Apophis as a bright light moving across the night sky. The asteroid is too small to be seen through small backyard telescopes. 
 
 The Slooh Space Camera webcast will begin at 7 p.m. EST (0000 Jan. 10 GMT). The Virtual Telescope webcast will begin an hour later at 8 p.m. EST (0100 GMT). You can watch both live webcasts of asteroid Apophis here on SPACE.com tonight. 
 
 Apophis will be just under 9.3 million miles (15 million kilometers) from Earth at the time of tonight’s webcasts, amateur astronomer Gianluca Masi of the Virtual Telescope Project told SPACE.com. 
 
 "Alone among all these near-Earth asteroids that have passed our way in recent years, Apophis has generated the most concern worldwide because of its extremely close approach in 2029 and [chances of a] potential impact, albeit small, in 2036," Slooh president Patrick Paolucci said in a statement. 
 
 An artist's rendering of the asteroid Apophis. 
 
 Credit: European Space Agency View full size image An artist's rendering of the asteroid Apophis. 
 
 In addition to asteroid Apophis, astronomers regularly scan the night sky for asteroids that may pose a potential impact threat to Earth. NASA's Near-Earth Object Office and Asteroid Watch program is based at the agency's Jet Propulsion Laboratory in Pasadena, Calif. 
 
 You can track Apophis directly via the Virtual Telescope Project here: http://www.virtualtelescope.eu/webtv/ 
 
 The webcast from the Slooh Space Camera can also be seen here: http://events.slooh.com/ 
 
 This story was provided by SPACE.com, a sister site to LiveScience. You can follow SPACE.com Managing Editor Tariq Malik on Twitter @tariqjmalik. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook. ||||| Here’s a tip for the planners among us: If you have dinner reservations or theater tickets for Sept. 22, 2135 (it’s a Thursday), now might be a good time to scuttle them. 
 
 Sometime the day before, scientists say, there is a small chance that an asteroid the size of the Empire State Building will smack into Earth, destroying a lot of living things on the planet. 
 
 But don’t worry. NASA has got you covered. 
 
 Forward-thinking astrophysicists and people who specialize in blowing things up with nuclear weapons have come up with a plan, which they swear was not drawn up by Bruce Willis. 
 
 If the asteroid — it is named Bennu — decides to go rogue, they could send a nearly nine-ton “bulk impactor” to push it out of Earth’s orbit. Or, more likely, they would gently nudge it out of its apocalyptic path using a nuclear device. 
 
 The scheme is called the Hypervelocity Asteroid Mitigation Mission for Emergency Response. Or, for people who love acronyms and despise subtlety: HAMMER. 
 
 Brent W. Barbee, the NASA aerospace engineer who helped author the study, insists that it is all theoretical. (His exact words: “Please don’t print that an asteroid is going to crash into Earth in The Washington Post.”) 
 
 But using granular detail and eye-glazing amounts of math, the researchers believe they have a viable solution to a world-rattling what-if question. 
 
 There is, of course, no massive mission to build a craft capable of playing a celestial game of space pool. The odds of Bennu actually hitting us are about 1 in 2,700. And the asteroid is not big enough to send us the way of the dinosaurs. 
 
 But that doesn’t mean there is no practical application, Barbee told The Post. 
 
 “We’re doing these design studies to prepare ourselves, so if we do find a threatening object, we’re better prepared to deal with it,” he said. 
 
 Things from space smack into Earth all the time. Most of them are not existential threats, but some are large enough to cause injury or property damage. Generating a working framework to avoid an Earth impact could save lives. 
 
 Until recently, the framework has basically been luck. 
 
 In 1908, what many believe to be an asteroid crashed into an area near the Podkamennaya Tunguska River in Siberia, according to the BBC. It struck with a force 185 times as powerful as the Hiroshima atomic bomb, flattened 80 million trees and reduced hundreds of reindeer to charred carcasses. 
 
 A century later in 2013, a 10-ton, 49-foot-wide meteor streaked over Russia’s Ural Mountains at hypersonic speeds, shattering windows and injuring 1,100 people, Fox News reported. (Most were injured by shattered glass as they watched the meteor cross the daytime sky). The meteor broke up before it hit the ground but still left scars in nearby ice that were the length of a bus. 
 
 The only reason more people weren’t killed or injured, Barbee told The Post, is because the objects struck places where there weren’t many people. 
 
 [With a spacecraft in trouble and the White House watching, SpaceX had to deliver] 
 
 NASA has a Planetary Defense Coordination Office that tries to detect dangerous asteroids and comets close to Earth’s orbit. 
 
 There are more of these things than many people think, Barbee said. Researchers detect about 1,000 new objects each year; 10,000 extraterrestrial objects beelining for Earth could still be unaccounted for. 
 
 The defense coordination office also comes up with plans for deflecting or destroying discovered objects. 
 
 What Asteroid Bennu provides, besides pretty good fodder for a doomsday cult, is an opportunity for scientists to test those theories. 
 
 Bennu is, the report says, a “well-studied roughly spherical body” that gives researchers a good target for their calculations — data points to punch into the algorithm. They can see Bennu with telescopes and track the impact its gravity has on other celestial objects. 
 
 Soon we will know more. NASA’s OSIRIS-REx spacecraft has been en route to Bennu for two years, according to the agency. It contains instruments that “will map Bennu and establish the composition of the asteroid, including the distribution of the elements, minerals and organic materials.” 
 
 It will also scrape off a 2.1-ounce sample and bring it back to Earth, NASA says. 
 
 If the odds are not in Earth’s favor, and Bennu becomes a bigger threat, OSIRIS-REx could be followed by a beefier craft that would break off a lot more. 
 
 Read more: 
 
 This millionaire has a promising idea for space exploration. But he says aliens are already here. 
 
 Dentists keep dying of this lung disease. The CDC can’t figure out why. 
 
 This ancient shark with a snake head and 300 teeth is why we should just say nope to the ocean 
 
 Scientists have identified the 50-foot creature that washed up on an Indonesian beach 
 
 Baby bison dies after Yellowstone tourists put it in their car because it looked cold
– The asteroid Apophis, whose reported threat to our planet has attracted widespread attention, is even larger than scientists believed, according to new images. Europe's Herschel Space Observatory says the asteroid is some 1,066 feet feet wide, some 20% wider than previously thought. That "translates into a 75% increase in our estimates of the asteroid's volume or mass," says the study's leader. Fortunately, we survived yesterday's passage, and reports that there was a 2.7% chance it would hit Earth in 2029 have been debunked. But scientists are still investigating the asteroid, which will pass near us again in 2036, LiveScience notes. At that point, there remains a one-in-200,000 chance of a collision, the BBC reports. "There is a small region of space—something we call a keyhole—and if it passes through that keyhole in 2029, it will come back and hit us on 13 April in 2036," says a scientist. It would carry 100 times the energy of our biggest nuclear weapons, he adds. "While there is no cause for alarm, similarly there is no room for complacency," writes Stuart Clark at the Guardian, which has video.