Posted on 10/15/2007 2:32:17 PM PDT by blam
Source: SETI Institute
Date: October 15, 2007
Long-lost, Dangerous Asteroid Is Found Again
Science Daily — 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 Center 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.
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. (Credit: Image courtesy of SETI Institute)
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. "The object was long recognized to be dangerous, but we didn't know where it was," says Jenniskens. "Now it is no longer just out there."
A designation as Potentially Hazardous means that 2007 RR9 is one of 886 (not 887) known asteroids bigger than 150 m (500 ft) in diameter that come to within 0.05 astronomical units of Earth's orbit (roughly 7,480,000 km or 4,650,000 miles). The size is estimated on the basis of the object's observed brightness and an assumed reflectance of 13 percent.
Jenniskens believes that this object may not, in fact, be an asteroid. "This is a now-dormant comet nucleus, a fragment of a bigger object that, after breaking up in the not-so-distant past, may have caused the gamma Piscid shower of slow meteors (IAU #236) that is active in mid-October and early November," he says. 2007 RR9 moves in a 4.70-year orbit, nearly all the way out to the distance of Jupiter. 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. According to Gareth V. Williams of the Minor Planet Center, it will pass Earth around November 6 at 0.07 AU, when the minor planet is at high latitudes in southern skies.
The original designation of P-L stands for "Palomar-Leiden," the juxtaposition of two observatory names that reflect what was a very fruitful collaboration by the trio of pioneer asteroid searchers Tom Gehrels of the University of Arizona, and Ingrid van Houten-Groeneveld and her husband Cornelis Johannes van Houten. Gehrels made a sky survey using the 48-inch Schmidt Telescope at the famed Palomar Observatory, long before modern asteroid reconnaisances, and shipped the photographic plates to the van Houtens at Leiden Observatory in the Netherlands. There, Ingrid discovered 6344 P-L on four plates taken on September 24-28, 1960. The trio are jointly credited with several thousand asteroid discoveries, but only 6344 P-L is a potential danger to Earth.
Peter Jenniskens is a meteor astronomer with the SETI Institute and author of "Meteor Showers and their Parent Comets" published by Cambridge University Press (2006). He is also credited with the identification of the parent body of the Quadrantid meteor shower. As it happens, he graduated from Leiden Observatory in 1992, before joining the SETI Institute.
Note: This story has been adapted from material provided by SETI Institute.
We must treat NEAs in the same manner as the French treat snails. We should consume them.
No, I don’t mean we EAT THEM! I recommend asteroid mining, and soon. Those suckers are PeGgyMaEs - Platinum Group Metal “motherlodes”. One peggymae NEA is equal in value to the annual gross Global income (one hell of a lot ‘a moola).
At present we have the technology, and lord knows, we have to get rid of those hazards. Right?
Yeah, that was my first hysterical response, too!
The NEA (National Education Association) is applying to the NEA (National Endowment for the Arts) for money to do a documentary on NEAs (Near Earth Asteroids). The only conclusion is that anything with the initials NEA is extremely dangerous.
I’d better move my car.
Search for Earth-Trashing Interlopers.
Hot Fudge Sunday *ping*...
Should be coming up any moment now.
Okay.
Hold on.
Here it comes...
I'm getting a cassegrain headache just thinking about it.
-PJ
Just Keck back and relax..............
Not just the Maya.......The Kabala-ists and Bible Code people agree........
...and a telescope?......
Yes, but Bolsheviks can’t use NEA to pass environmental regulation and treaties for controlling private property and industry.
I'll Lick the chocolate off my Palomar cookies.
-PJ
>> We must treat NEAs in the same manner as the French treat snails. We should consume them. No, I don’t mean we EAT THEM! I recommend asteroid mining, and soon.
~~~~~~~~~~~~~~~~~~~~~
Long ago, the mice had a general council to consider what measures they could take to outwit their common enemy, the Cat.
Some said this, and some said that; but at last a young mouse got up and said he had a proposal to make, which he thought would meet the case.
“You will all agree,” said he, “that our chief danger consists in the sly and treacherous manner in which the enemy approaches us. Now, if we could receive some signal of her approach, we could easily escape from her.
I venture, therefore, to propose that a small bell be procured, and attached by a ribbon round the neck of the Cat. By this means we should always know when she was about, and could easily retire while she was in the neighborhood.”
This proposal met with general applause, until an old mouse got up and said: “That is all very well, but who is to bell the Cat?”
I am truly Hubbled.....
One of my favorite books.
-PJ
You need to get a Clube.
Its the New World without the pesky natives.
-PJ
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