On Wednesday (Jan. 13), an object called 2010 AL30 will fly by Earth at a distance of just 130,000 km (80,000 miles). That's only one-third of the way from here to the moon, ie: very close.
Earlier reports had suggested the object might be manmade, but according to NASA's Jet Propulsion Laboratory's Small Body Database, 2010 AL30 has now been classified as an "Apollo" class near-Earth asteroid (NEA).
It will miss us, and if it did hit us, it wouldn't do any damage anyway, but chatter between planetary scientists suggest that the asteroid gives us a new standard: a 10-meter-wide asteroid can be detected two days before it potentially hits Earth. A pretty useful warning if you ask me.
Apollo class asteroids cross the path of the Earth and are confined to an orbit around the sun similar to that of our planet. This classification is named after an asteroid called 1862 Apollo that was discovered in 1932. [Thanks to Charles Bell for notifying me about this development.]
Expert astronomers will be able to observe it shining with a brightness of a 14th magnitude star (the approximate brightness of Pluto's weak glow as seen from Earth) as it dashes through the constellations of Orion, Taurus, and Pisces (further details about the orbit of 2010 AL30 can be found on NASA's Solar System Dynamics website).
What makes this near-Earth object (NEO) special is that it has an orbital period of almost exactly one year. This fact led some scientists to speculate that 2010 AL30 could be a manmade object and not an asteroid. After all, there's a lot of space junk up there, there's every possibility that it could be a spent rocket booster or some other chunk from a spacecraft.
But it appears to be just be coincidence that the NEO has the same orbital period as Earth.
Andrea Boattini of the Catalina Sky Survey made the interesting point that 2010 AL30 is a great example of how much of a warning we'd have for an object of this size that's headed for Earth. After all, the discovery was only announced on Jan. 11, two days before its Earth encounter.
It is worth noting that even if 2010 AL30 did hit Earth, it would most likely explode high in the atmosphere (with the energy of a small nuclear bomb), posing little danger to anyone on the ground. Impacts of this size happen every year.
The discovery of this 10-meter-wide object is testament to the increasing capabilities of the international community of asteroid hunters. When 2010 AL30 does make its closest approach on Jan. 13, they can take a more detailed look at the small visitor, verifying whether it is indeed an asteroid or a manmade object. However, it would appear that the consensus is that it's a natural inhabitant of our solar system, passing safely through our neighborhood, providing asteroid hunters with an interesting target to study.
Sources: Spaceweather.com, Remanzacco Observatory