Surprise! Unknown Asteroid Buzzed Earth
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A previously undiscovered asteroid came within 14,000 km (8,700 miles) of Earth last week, and astronomers noticed it only 15 hours before closest approach. On Nov. 6 at around 16:30 EST a 7 meter asteroid, now called 2009 VA, came only about 2 Earth radii from impacting our home planet. This is the third-closest known non-impacting Earth approach on record for a cataloged asteroid.
Early on Nov. 6 the asteroid was discovered by the Catalina Sky Survey and was quickly identified by the Minor Planet Center in Cambridge MA as an object that would soon pass very close to the Earth. JPL’s Near-Earth Object Program Office also computed an orbit solution for this object, and determined that it was not headed for an impact.
The two closer approaches include the 1-meter sized asteroid 2008 TS26, which passed within 6,150 km (3,800 miles) of the Earth’s surface on October 9, 2008, and the 7-meter sized asteroid 2004 FU162 that passed within 6,535 km (4,060 miles) on March 31, 2004. On average, objects the size of 2009 VA pass this close about twice per year and impact Earth about once every 5 years.
Only thirteen months ago, another asteroid, 2008 TC3 was discovered under similar circumstances, but that one was found to be on a trajectory headed for the Earth, with impact only about 11 hours away. It impacted in a remote area of Africa; no one was injured and fragments have since been recovered for study.
Source: JPL NEO office
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Did this close approach negate the possibility of this asteroid being a future threat or was its orbit sufficiently changed to make this body no longer a probabilistic threat?
No word, Jon, on that from NASA yet. I’m sure they’re still figuring out the trajectory of this thing since they’ve just discovered it. If the image they provided is accurate (top), it appears its pass by Earth had a definite effect on the object’s future trajectory.
Nothing but a bit of Planet X. Nothing to worry about. For a couple years…..ok sorry just had to say it . Someone will hear about this and use it as “proof” of our impending doom.
Looking at the trajectory, that one will never come back!
Thanks to Nancy and LC for their response to my query
What was the size of the thing?
7m
What sort of damage could we expect from a 1m – 10m piece of rock? I can’t remember the numbers off-hand.
What sort of damage to expect is hard to say. Sufficiently large ones seem to make craters between 7 and 10 times their width. Rocks of a few meters across often break up and do very little damage – like the one which recently came down in Africa. Asteroids of about 30 meters across are supposed to have the potential of being “City Wreckers” – thanks be to Goodness, no proof has been provided…
The impact simulator says a 7 m asteroid is unlikely to hit ground in one piece.
Here are the details:
http://www.lpl.arizona.edu/impacteffects/cgi-bin/crater.cgi?dist=2000&distanceUnits=1&diam=7&diameterUnits=1&pdens=&pdens_select=3000&vel=17&velocityUnits=1&theta=45&wdepth=&wdepthUnits=1&tdens=2500
The atmosphere does a pretty good job of protecting us. A 25-50m asteroid is about where you start getting nuclear attack energy levels deposited on an area of land.
LC
Aodhhan: Where did you get this information?
LC
@Aodhhan Have you got a Celestia data file for this object with it’s new orbit? If not, can you fill in the blanks?:
“2007 VA” “Sol”
{
Class “asteroid”
Mesh “asteroid.cms”
Texture “asteroid.jpg”
Radius ?
EllipticalOrbit
{
Period ?
SemiMajorAxis ?
Eccentricity ?
Inclination ?
AscendingNode ?
ArgOfPericenter ?
MeanAnomaly ?
}
Albedo ?
RotationPeriod ?
}
How many miles away was it?
You just can’t win, can you?
But I, for one, thank you for having switched to SI in your posts.
(Father Google sez: 14 000 kilometers = 8 699.19669 miles)
We don’t use SI mesurements here in America. So, if the article is meant to be read by a US audience, the article should use terms we are familiar with. After all, one wouldn’t write a paper in Japanese if it was meant for an English speaking audience. How hard is it to post US labels as well? Like,
xxx KM (xxx miles)