Emily Lakdawalla • Jun 14, 2012
Chang'E 2 has departed Earth's neighborhood for...asteroid Toutatis!?
EDIT: I have posted an update with answers to some of the questions I asked below.
User "paolo" on unmannedspaceflight.com pointed yesterday to a Chinese spaceflight discussion forum in which a moderator posted the following terse statement yesterday (in Google translation):
The CE-2 in April, has left the L2 to probe asteroid is expected to close rendezvous with an asteroid in January next year.
Chang'E 2, you may remember, was China's second lunar orbiter; it departed the Moon on June 8, 2011 and arrived in the Sun-Earth L2 point on August 25, where it has been ever since. Until now, evidently!
Chang'E 2's asteroid target, according to a forum commenter, is asteroid 4179 Toutatis. Toutatis would be a reasonable target; according to a query I just ran on the JPL HORIZONS ephemeris service it will be approaching to within 0.0463 AU (just under 7 million kilometers) of Earth at 06:40 on December 12 of this year.
The source of the news is a presentation by Chinese cosmochemist and Chang'E program chief scientist Ouyang Ziyuan. The hour-long presentation can be viewed here, but of course it's in Chinese and not subtitled so I am unable to understand a word except "xie xie." If there is any reader who does understand Chinese and who might be able to find and quote a few key statements in this presentation I would say "xie xie" very much! I want to know: when exactly did Chang'E 2 depart? When will be is its closest approach to the asteroid? What does the Chang'E 2 science team hope to accomplish in terms of observations -- especially imaging? Help!
Here is the video: