Four comets in two days (December 26, 2008)

Hi-res TIF image (2.1M)


Quicktime Movie: Large ( 33M), Medium (3.8M) Small (570K)

SOHO's C2 coronagraph spotted 4 comets in just over two days, but the fourth one during that period (Dec. 21- 23, 2008) was the brightest and most noteworthy. It was Comet Christensen (P/2003 K2), the first comet "recovered" by a spacecraft. The other three comets can be spotted zipping out of the lower left corner of the image: first, a pair of comets in tandem appear near the beginning of the sequence, then around 17:00 UT on the 22rd, another small comet, also belonging to the Kreutz family of sungrazing comets, appears and also quickly disappears.

But at 23:00 UT Comet Chirstensen begins to cross left to right, traveling behind the occulting disk and reappearing on the other side. (Data gaps cause some of the motion to be jumpy.) It was first discovered in May 2003 by astronomer Eric Christensen and then, as sometimes happens to new comets with poorly-known orbits, it was lost again, its orbital path uncertain. Comet Christensen went missing for more than five years until STEREO found it again on Dec. 13-14, 2008. Australian comet-hunter Alan Watson, while scouring data from the STEREO H1 wide-angle instrument, found the faint comet in the data. The comet has been officially recovered and is known to be a periodic comet, meaning it will return on its known orbital path on a regular basis.

Go here for the whole story.

SOHO began its Weekly Pick some time after sending a weekly image or video clip to the American Museum of Natural History (Rose Center) in New York City. There, the SOHO Weekly Pick is displayed with some annotations on a large plasma display.

If your institution would also like to receive the same Weekly Pick from us for display (usually in Photoshop or QuickTime format), please send your inquiry to steele.hill@gsfc.nasa.gov.