For now, is just about the most informed comment I can make, too.

A thought: would anyone who is a more skilled image processor than I like to take a crack at a rigorous approach to determining whether we can tell if we're looking at multiple copies of the same image, or at different images? Are we even sure that the rumored 47km one (of which we only have a screen grab from a webcast, as far as I know) shows anything distinctly different from the ones in the multi-image montage?

I took the smallest image and blew it up to the size of the largest, pasted it over the largest and flipped between them (as layers in Photoshop). There seemed to be a real sense of a small amount of rotation - really a change in view direction, not rotation of the asteroid. I can't post it as an animated GIF (maybe someone else can) but it looked real to me.

Phil

Thank you. Since I have a history of "seeing" parallax in image pairs that don't have it, I didn't trust my own examination.

Somehow I am reminded of the time of the Huygens landing, when somebody posted an anaglyph of two identical DISR images on the web, and people claimed to see depth...

the translation of an interview on the Chinese-led international effort to refine the orbit of Toutatis, using telescopes in China, Hawaii and Chile
http://translate.googleusercontent.com/tra...fEayz1jbqoh7j2g

I was wondering whether optical navigation was ever carried out by CE-2 before the encounter. I don't think any of the cameras was suited for this. the webcams were probably not sensitive enough to spot Toutatis more than a few hours before the encounter, and the science camera had its well known limitations

I was able to get a copy of this paper, which I will not redistribute. it's in Chinese, but you also have a table with the camera characteristics that is quite understandable.
for pixel count, the "landing" and engine monitoring cameras are 1280 x 1024, while the two other cams are 1024 x 1024. they are all 8-bit, color cameras.
the solar panel monitoring camera is just 358 grams in mass and consumes 2.45 W.
what the paper lacks is a table giving the field of view of each camera. in the case of the engine monitoring one it is stated in the text to be 40 degree wide, while the antenna monitoring camera seems to be a 139 degree fisheye, if I understand correctly the google translation.
there is a picture of each camera, and the solar panel monitoring one looks slightly different from the others for its longish optics, probably some kind of narrow angle lens (which would make sense for its use in the Toutatis encounter)

I am surprised that an optical astronomy campaign would have been needed to refine the orbit of Toutatis. I would have thought that the radar data collected over the last two decades would have made it one of the best known orbits of any asteroid.

Phil

I don't think it was strictly needed either. after all, the ephemeris of Toutatis in JPL's Horizon have uncertainties of the order of several kilometers, which is notable for an asteroid. plus, it's not through optical astrometry that you are going to get a more precise orbital determination.
my feeling is that the Chinese wanted to demonstrate the full process that would normally be needed for an asteroid mission. I have seen lists of alternative flyby candidates for CE-2 and they are all smallish, unnumbered objects for which an optical astrometry campaign would have been necessary.

just found a paper (marked "for academic exchange only") that gives some technical overview of the asteroid flyby target selection
http://www.docin.com/p-413770925.html

I am a bit surprised and disappointed that neither Science nor Nature (nor Aviation Week) have said a single word on the flyby in their latest issues...

I agree. Three weeks have passed and not another peep about the success in the Chinese news media. This is very odd.

SBAG meeting:

http://www.lpi.usra.edu/sbag/meetings/jan2013/agenda.shtml


9:30–10:15 a.m. Chang'e 2 flyby of Toutatis (Han Li, Chinese Academy of Sciences)


This is where we can expect something useful.

Phil

I couldn't see the presentation on webex (I was at work at the time) and I have seen only a few details of it on twitter and facebook. anybody knows more?

http://www.lpi.usra.edu/sbag/meetings/jan2...CE_Toutatis.pdf

!

Phil

the repositioning of the solar panels reported in the timeline here makes even more sense: they had the solar panels covering part of the field of view and they ensured that they would be seeing the dark side of them.
it would be great to have the video embedded in that presentation...