Looks to me like a tadpole wriggling in that big, dark pond we call outer space. C/2012 V4, the likely return of Comet Pons-Gambart, last seen in 1827, has been spotted in pictures taken by one of the SECCHI (Sun Earth Connection Coronal and Heliospheric Investigation) cameras on board the STEREO-B solar probe. The instrument watches the space between Earth and the sun, monitoring the progress of solar storms before they impact our planet.
The twin STEREO probes orbit well ahead and behind Earth, so they can photograph both the front and back sides of the sun. C/2012 V4 and its tadpole tail show up so well because from STEREO-B’s location, it’s considerably closer than it is from here on Earth.
You may have heard that the comet, which appears to be headed in Earth’s direction, could actually strike our dear planet. Don’t worry, won’t happen. C/2012 V4 lies some 144 million miles away or more than 1.5 times the Earth-sun distance and moves farther away every day. On Dec. 18, it will swing wide around the sun at a distance of 75 million miles and then recede into the depths. Amateur astronomers with 8-inch or larger telescopes and a clear view down to the southwestern horizon can use the map to try and spot this long-lost visitor. It’s currently about magnitude 8.5, about as bright as it will get.
Be sure to click on the photo at top to watch a short video of the comet’s movement over several days time. Alan Watson of Australia did a great job combining SECCHI photos to show how the tail of the C/2012 V4 wriggles as high-speed particles from the sun called the solar wind sweep past. They make the comet come alive!