Newly discovered asteroid buzzes Earth inside moon's orbit
A recently discovered asteroid gave Earth a close shave on Dec. 11, zipping between our planet and the moon just two days after astronomers first spotted it.
According to researchers, the near-Earth asteroid 2012 XE54, which was discovered Sunday (Dec. 9), came within 140,000 miles (230,000 kilometers) of our planet at about 5 a.m. EST (1000 GMT) Tuesday.
For comparison, the moon orbits Earth at an average distance of 240,000 miles or so (386,000 km).
Astronomers estimate that 2012 XE54 is about 120 feet (36 meters) wide -- big enough to cause substantial damage if it slams into Earth someday. An object of similar size flattened 800 square miles (2,000 square km) of forest when it exploded above Siberia's Podkamennaya Tunguska River in 1908.
Asteroid 2012 XE54 also passed through Earth's shadow a few hours before its closest approach, generating an eclipse on the space rock's surface, researchers said.
"Asteroids eclipsing during an Earth flyby are relatively rare," Discovery News quoted astronomer Pasquale Tricarico, of the Planetary Science Institute in Tucson, Ariz., as writing in a blog post Monday (Dec. 10).
The first known case, Tricarico added, was "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."
2012 XE54 will be coming back to Earth's neighborhood before too much longer. The asteroid completes one lap around the sun every 2.72 years.