A 60 metre rock (2006 QM111) discovered by Rob McNaught at Siding Spring, Australia, is just passing through the Earth moon system at a distance of about 165,000 km away.

Ephemeris:
e = 0.597729969006656 i = 11.7425138387124 deg
q = 0.999868167680594 AU w = 171.772016736111 deg
a = 2.48556464723851 AU node = 143.838851994058 deg
Q = 3.97126113 AU M = 4.57556616585141 deg
P = 3.9187 y n = 0.251516 deg/d
TP = 2006-08-11.8080874 (2453959.3080874) TDB

Date TT R. A. (2000) Decl. Delta r Elong. Phase V
2006 08 31.9 05 50.09 -66 04.8 0.00111 1.009 90.8 89.2 16.2
2006 09 01.0 08 54.26 -31 05.1 0.00161 1.008 46.9 133.0 19.9

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`Irony` actually does mean `metal like`...

Argh!!!!!!

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If this writing is blue you're going too fast!

Thanks for the heads-up on this asteroid. This thing came close! From an overhead view it appeares to be on an impact trajectory:

Moment of closest approach


Saved by the z-axis

Blob, the link and elements seem to pertain to 2006 QN111, not 2006 QM111.
Elements for 2006 QM111 are:

Epoch = 2006-09-22.0 (2454000.5) TDB
e = 0.729996700971176 i = 1.42332455430029 deg
q = 0.699844016661727 AU w = 256.584071810182 deg
a = 2.5919832060534 AU node = 155.801993529104 deg
Q = 4.48412240 AU M = 354.672944000909 deg
P = 4.1731 y n = 0.236187 deg/d
TP = 2006-10-14.5544096 (2454023.05440961) TDB

Link

Grant Hutchison

Referrining to the original link on 2006 QN111, I'm not sure if I'm reading the table right. It seems to me that is suggesting that on August 16, 2079 that 2006 QN111 will pass only 0.51 Earth Radii from Earth. This doesn't make sense unless they're referring to altitude as 0.51 Earth radii from Earth is below Earth's surface (impact!).

Furthermore, there's a big discrepancy between that distance and the one given by JPL Horizons Ephemeris System, which has 2006 QN111 ~3/4 of a billion kilometers from Earth on that date. Am I reading the data in Blob's link correctly? Probably not. Look at the link for Apophis: http://neo.jpl.nasa.gov/risk/a99942.html . It also lists a distance of 0.53 Earth Radii for the 2036 passage, but current estimates put it several lunar distances away on that date. What does "Distance r_Earth" mean?

I think this does relate to a possible impact orbit for 2006 QN111, passing 0.51 Earth radii from the geocentre. But it has (as the table shows) a probability of only 2.3x10^-6, given the object's orbital elements as presently determined.

Grant Hutchison

But that's what doesn't make sense to me. Earth's surface is 1 Earth radii from the geocenter, so 0.51 Earth radii from the geocenter is below the surface for a guaranteed impact.

It also doesn't make sense to me that if they're predicting a 0.51 Earth radii miss (~3000 km) that the probability would be as low as 2.3e-6 for an encounter 73 years away.

@grant hutchison
Doh,
tnx for correcting me,
With all the rocks out there its easy to mix them up.

Web link:

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`Irony` actually does mean `metal like`...

Yes, but they're exploring the probability space of the body's future trajectory with a limited number of "virtual asteroids", which have greater or lesser probability of representing the true trajectory, depending on how many standard deviations they lie from the mean elements as they are currently measured.
If this sort of swarm turns up a hit, it's vanishingly unlikely to be a neat grazing impact. There's more information, a little light on detail, one their introductory page.

Grant Hutchison

Also worth noting, is that this seems to be a rock about 60 meters in diameter, and so would be a relatively good target for trying some techniques for nudging asteroids. It's mass is substantial, but not TOO substantial.

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Forming opinions as we speak