Some news about this interesting target. As a reminder, it will make its close flyby on Wednesday January 13 at 12:46 pm UT (4:46 pm PST) so in a few hours, when it will pass at 122,000 km from Earth.

Yesterday, Tuesday Jan 12, Lance Benner reported successful observations with the radar Goldstone antenna using the recent orbit estimate. I am assuming that they are processing the data to derive the size, shape and the true nature of the target.

Interestingly using an update of the orbit, Bill Gray from the MPML list mentioned that the target has not been near us for a long time (0.014 +/- .004 AU on 12 January 1929). This result is true only assuming gravitational forces and neglecting solar wind interaction which should played a major role for such small object (see the famous Yarkosky effect that I mentioned in several of my previous posts). We need to know precisely the size, shape and the albedo to be able to predict this effect so that’s one of the reasons we need these radar observations.

Michael Kahn, mission analyst at ESA, posted on his blog a discussion on the nature of this object that I summarized below. “Probably 2010 AL30 is of natural origin. However, the possibility that it is man-made cannot be completely excluded. If so, it might be the upper stage of a rocket used in an earlier planetary mission, possible to Venus. “. He noticed that there was a close approach to Earth on January 12, 2009 at 0.01 AU and a close approach to Venus on the Spring 2006 suggesting that this target could be a “Fregat upper stage of the Soyouz launch vehicle that launched the ESA spacecraft Venus Express on November 9, 2005, with Venus arrival on April 11, 2006. ”
It is worthy to notice that there is a difference in the analysis of the M. Kahn and B. Gray, most likely due to the fact that they used different orbit since it is being refined on a regular basis by the MPEC.

If you want to see the asteroid but don’t have a telescope you can have a look on the movies made by Patrick Wiggins (posted below). He used his Celestron C-14 @ f/5.5 with an SBIG ST-10 binned 3×3 CCD camera, and a clear filter  to observe the target on January 13 from his observatory (code 718) located in Utah near the city of Tooele. The FOV of these movies is about 18′ x 26′.

a series of 30 15" exposures tracking on the target between 07:18:16 and 07:27:29 UTC (by P. Wiggins, obs code 718)
a series of 30 15sec exposures tracking on the target between 07:18:16 and 07:27:29 UTC by P. Wiggins (click on the image to start the movie)
a series of 73 x 1 sec exposures tracking at normal sidereal rate between 06:38:42 and 06:44:25 UTC:
a series of 73 x 1 sec exposures tracking at normal sidereal rate between 06:38:42 and 06:44:25 UTC:

I am hoping to post soon the result of the radar observations. The bets are still opened. 🙂

F.

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