Echoing the re-discovery of America by the Spanish long after an earlier Viking reconnaissance, astronomers have learned that a recently observed asteroid - one that could potentially hit the Earth - was actually first observed nearly a half-century ago. Researchers at the Minor Planet Centre of the Smithsonian Astrophysical Observatory in Cambridge, MA have confirmed work by SETI Institute astronomer Peter Jenniskens that the recently discovered asteroid 2007 RR9 is in fact the long-lost object 6344 P-L. 6344 P-L was last seen in 1960, and ever since has had the peculiar distinction of being the only Potentially Hazardous Asteroid without a formal designation.
Astronomers have found that the recently discovered Earth threatening asteroid 2007 RR9 is in fact the long lost object 6344 P-L observed nearly half a century ago. Astronomers at the Minor Planet Centre of the Smithsonian Astrophysical Observatory in Cambridge, MA have confirmed work by SETI Institute astronomer Peter Jenniskens that the recently discovered asteroid 2007 RR9 is in fact the long lost 6344 P-L. The object was last seen in 1960, and ever since has had the peculiar distinction of being the only Potentially Hazardous Asteroid (PHA) without a formal designation.
"2007 RR9 moves in a 4.70-year orbit, nearly all the way out to the distance of Jupiter, and because of this elongated orbit, it has a Tisserand parameter of T = 2.94, which defines it dynamically as a Jupiter Family Comet (T = 2.0 - 3.0), not an asteroid (T > 3.0). So far, this object has not yet been seen to be even weakly active, but the now dormant comet is still moving closer to the Sun. It is sliding rapidly toward visibility in the southern hemisphere, and is expected to brighten to magnitude +18.5 in mid-October" - Peter Jenniskens, SETI Institute astronomer.
For more than 40 years, an asteroid believed to be potentially dangerous to Earth has been essentially lost to view. But no more. The so-called 6344 P-L was first spotted in 1960, and given the designation Potentially Hazardous Asteroid meaning that its orbit took it within .05 astronomical units (about 4,650,000 miles) of Earth's orbit. But astronomers lost track of it; left behind was only a number and a vague sense of threat. However, meteor researcher Peter Jenniskens of the SETI institute now argues, with confirmation from the Smithsonian Astrophysical Observatory' Minor Planet Center, that this wayward wanderer is in fact the same thing as the recently discovered 2007 RR9, making a reappearance this year as part of a 4.7-year orbit.