As Comet Elenin passed to within just 7 million kilometers of the STEREO (Behind) spacecraft, NASA rolled the spacecraft to take a look at it (Aug. 1, 2011) with its wide angle HI-2 instrument. Though the observation lasted only a little over an hour, the fuzzy looking comet can be seen moving across a small portion of the sky. STEREO will be taking these one-hour observations every day through August 12.
The comet is seen by the HI-2 telescope between August 1-5, and by the higher resolution HI-1 telescope between August 6-12. From August 15 onward, the comet enters the HI-1 telescope's nominal field of view,
1. The closest the comet will come to Earth is 0.23 AU (Astronomical Units), or approximately 34-million kilometers, so it poses no threat to us. We will attempt to keep this page updated with the latest observations.http://stereo.gsfc.nasa.gov/gallery/item.php?id=selects&iid=154