The cosmos threw a curve ball at us, but a near-Earth object (NEO) called 2010 AL30 missed by over 80,000 miles. Although the object was too small to cause any damage, if it did hit, it would generated an impressive firework display before being vaporized by the upper atmosphere.
But astronomers didn't expect a collision and the 10 meter wide NEO flew past peacefully a few hours ago.
Although NASA officially declared the near-Earth object (NEO) an ‘Apollo class' asteroid yesterday, there still seems to be some ambiguity as to what 2010 AL30 really is. The strange one year orbit of the NEO has led some scientists to speculate that it originated from Earth. Perhaps it's an old and used rocket booster?
Through careful analysis of the object's motion past Earth, a lot of information has been gathered about the orbital characteristics of 2010 AL30. Now, a European Space Agency (ESA) mission analyst has come forward with his own investigation into the strange orbit of the ‘asteroid' 2010 AL30.
Michael Khan did the math and back-tracked 2010 AL30′s path through the solar system and believes that the object's life began with the launch of the ESA Venus Express mission in 2005.
"Probably 2010 AL30 is of natural origin. However, the possibility that it is man-made cannot be completely excluded," Khan said in an article on his blog. "If so, it might be the upper stage of a rocket used in an earlier planetary mission, possibly to Venus. The current orbit would have been acquired through a Venus swingby and other orbital perturbations."
This idea led him to speculate that there might be an outside chance that the NEO could be the Fregat upper stage of the Soyuz launch vehicle that blasted Venus Express into space on Nov. 9, 2005. The spacecraft arrived at Venus on April 11, 2006.
After an in-depth analysis of where the used rocket could be located at this time in space, Khan sees "coincidences galore" in his calculations and the observed orbital characteristics of the object.
This is certainly a very interesting (and pretty cool) factor to consider as there are other examples of spent rockets floating around in space that have been observed from Earth.
Take the chaotic story of an object named J002E3 for example: In 2002, this object became trapped in Earth's gravitational field and orbited our planet until 2003. It was kicked back out into space by interactions with the moon's gravitational pull. In fact, for a short time, the Earth technically had two ‘moons' in orbit; one natural and the other a Space Age antique.
After a thorough investigation it transpired that J002E3 was a huge piece of space junk from the Apollo era; it was the upper stage of the Saturn V rocket that launched Apollo 12 in 1969.
So is the NEO an old piece of ESA property or is it just a small rock causing a whole lot of excitement?
The answer probably won't come until the results from NASA's Goldstone Solar System Radar carries out an analysis of 2010 AL30. The California-based radar dish is part of the Deep Space Network and it provides some of the most detailed observations of NEOs.
Goldstone does this by ‘bouncing' radio waves off asteroids that cross the Earth's orbit around the sun. These reflected radio waves are then received and turned into usable data. I'm hoping Goldstone will be able to construct a radar image of 2010 AL30 so we can see the shape of it; that would be the compelling proof as to whether the NEO is natural or man-made.
As detailed by expert blogger Emily Lakdawalla over at the Planetary Society, the Goldstone scientists have detected a strong signal from 2010 AL30, and they've deduced that it's spinning with a period of only 9 minutes, which is fast for an asteroid. (As a comparison, that's not nearly as fast as the fastest spinning object discovered in the solar system to date - that record goes to the near-Earth asteroid 2008 HJ with a rotation period of only 42.7 seconds.)
So, let's wait and see what results the radar campaign returns...
Sources: Go For Launch, Planetary Society blog, Remanzacco Observatory.