It seems a new Apophis like asteroid was discovered recently :
http://neo.jpl.nasa.gov/risk/
Asteroid 2009WM1 , estimated to have a diameter of about 280m was discovered about 7 days ago and ranks very high in the Torino Hazard scale .

Currently its Torino rating is 1 out of 10. Not very high, if you ask me.

Fred

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Apparently less than 1% probability of collision?


Risk of 2009WM1

I always wondered what would happen if we were to perturb the motions of a number of different asteroids by trying to "mine" them or "land" on them? However, to me, that is still up for debate(?).

They only have seven days' worth of observations. I'd guess that the error bars are pretty big at the moment. In another month, I'd say that most if not all of the potential 145 collisions will disappear.

Fred

__________________
"For shame, gentlemen, pack your evidence a little better against another time."
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Just to be clear, a rating of 1 on the Torino scale is defined as follows:

"A routine discovery in which a pass near the Earth is predicted that poses no unusual level of danger. Current calculations show the chance of collision is extremely unlikely with no cause for public attention or public concern. New telescopic observations very likely will lead to re-assignment to Level 0."

A rating of 8, 9 and especially 10 would be considered a very high rank of the Torino scale.

I'm afraid I have to agree with Fred and jaksichj, frankuitaalst.

Eric

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I agree with your statement . Hazards usually go down as more observations become available .
I hope Fred and jaksichj are right :-)

No worries, it's not even close to the size of Texas.

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Apophis was a 4 when it was first detected. This one should rise no worries.

In the past, Torino ratings have always reduced to 0 as adequate observations became available.

Has anyone seen any sort of research or simulation on how we should expect a Torino rating to evolve for a newly discovered asteroid that actually was on an impact trajectory?

Due to even minor inaccuracies in the observations, around any calculated nominal orbit there is an error region. If the earth is inside that region, then there is a possibility of impact. As more observations become available, the possible error region becomes smaller. That eventually leads to one of two possible outcomes - as more observations are made, probability of impact goes to 0 or 1.

But the probability of impact should follow some trajectory through time, to one or the other of those outcomes. I.e. starts very small and increases through time to 1 or starts very small and decreases through time to 0. It would be interesting to understand the shape of those curves.

In other words, at this stage in the observational history of a real impactor, something that had taken dead aim on a direct hit, what Torino rating should we expect?

After 9 days of observations, the number of potential impacts is down to 94...

Fred

__________________
"For shame, gentlemen, pack your evidence a little better against another time."
-- John Dryden, "The Vindication of The Duke of Guise" 1684

And after 12 days, the number of potential impacts is 1. With a probability of 7.6e-07, i.e. 0.000076% chance of Earth impact or 1 in 1,316,000 chance or 99.99992400% chance the asteroid will miss the Earth.

Move along folks. Nothin' to see here.

Fred

__________________
"For shame, gentlemen, pack your evidence a little better against another time."
-- John Dryden, "The Vindication of The Duke of Guise" 1684

Cool. Thanks for the posts showing how impact probability usually decreases with more observations. Might make some googling person sleep with less worries.

__________________
"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin | Meet the OOONG TOE.
"Your right to hold an opinion is not being contested. Your expectation that it be taken seriously is." -- Jason Thompson
'No, mad's when you froth at the mouf,' said Gaspode. 'He's insane. That's when you froth at the brain.'

Depends on what percentage of the "virtual asteroids" would impact Earth, which probably would vary quite a bit by the nature of the asteroid and the resulting uncertainty in measurement. Method is described in Near Earth Object Program: Impact Risk Assessment.

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0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 ...

Good source !
There's another program running called Neodys ( Spain and Italy ) which also monitors (Near Earth) Asteroids . Their software seems to be redundant to the software used by JPL but gives at first sight slightly other values than the values JPL provides , if we look at the close approach distances .
According to Neodys the asteroid will make a close pass to Earth in 2059 at about 5 lunar distances ( at the nominal path ) ie 0.012 AU .
See comparison in annex ( data after 12 days of observation )

Seems we're on the safe side ! No Apophis !

For those who are interested in how the path of the asteroid evolves using different data of obserrvations :
http://www.orbitsimulator.com/cgi-bi...113160/247#246
The white line represents the actual data ( after 12 days of observation).
The blue/white dot at 12 'o clock represents the Earth-Moon system .

Attached Images

Comp 2009WM1.JPG (50.7 KB, 1 views)

And just to close the book on this once and for all, 2009 WM1 was removed from the Impact Risk page on Dec 9, 2009.

[cue Dragnet theme]

Fred

__________________
"For shame, gentlemen, pack your evidence a little better against another time."
-- John Dryden, "The Vindication of The Duke of Guise" 1684

Reminds me of a funny:

The Children's Television Network production of SQUARE ONE/PBS/1987 featured a segment called "Mathnet." This parody of DRAGNET starred a droll female investigator who remarked "My name is Monday...I'm a Mathematician." A classic Stan Freberg parody entitled "St. George and the Dragonet" began "The legend you are about to hear is true--only the needle should be changed to protect the record."