Earth prepares for a double flyby of asteroids in the next day

December 12, 2012 - SPACE - As Earth prepares for a double flyby of asteroids in the next day, astronomers have created this unique view of the earth - from an asteroid as it passes close by.  This animation shows the Sun and the Earth as observed from the asteroid 2012 XE54, which alongside a long-studied giant space rock named Toutatis will pass close to Earth later today.  Luckily, there is no danger of either hitting Earth - but scientists say the unique occurrence could help them learn a lot about asteroids. 
Asteroid 2012 XE54 was only recently discovered, and will safely pass between the Earth and the Moon’s orbit at a distance of about 226,000 km (141,000 miles) or about .6 lunar distances. However, it will have a unique path. 'A close analysis of the trajectory of this asteroid reveals that it will likely cross the Earth's shadow, causing a partial eclipse of the asteroid a few hours before reaching its minimum distance with the Earth,' said Pasquale Tricarico of the Planetary Science Institute, who created the animation above.  Asteroids eclipsing during an Earth flyby are relatively rare, with the first known case of asteroid 2008 TC3 which was totally eclipsed just one hour before entering Earth's atmosphere over Sudan in 2008, and asteroid 2012 KT42 experiencing both an eclipse and a transit during the same Earth flyby in 2012. 
 The asteroid is one of two set to pass by Earth.  4179 Toutatis, with a shape that has been described as a 'malformed potato' will pass 6.9 million kilometers (4.3 million miles) away from Earth, or more than 18 times the distance from the Earth to the Moon.  At 4.46 kilometers (2.7 miles) long and 2.4 kilometers (1.5 miles) wide, astronomers say it is considered a potentially hazardous asteroid because it makes repeated passes by the Earth, about every four years.  In comparison, the asteroid that is thought to have destroyed the dinosaurs was approximately 10 km (6 miles) wide.  It's passing will be streamed online by the Slooh Space Camera  At its maximum brightness, experts say Toutatis might be barely visible through binoculars. - Daily Mail.