Comet C/2011 L4

In early March 2013, Comet PanSTARRS became visible to the naked eye in the night sky in the Northern Hemisphere -- appearing with a similar shape and brightness as a star, albeit with a trailing tail. Up in space, however, NASA's STEREO (Solar TErrestrial RElations Observatory) has an even better view. This movie, captured by the STEREO-B spacecraft on March 9-12, shows the comet and its fluttering tail as it moves through space. The stationary planet on the right is Earth, and the moving planet on the left is Mercury. The material moving in from the left is solar wind streaming off the sun, which is out of view on the left. Comet scientists say the tail looks quite complex and it will take computer models to help understand exactly what's happening in STEREO's observations. The comet should remain visible to the naked eye through the end of March. Comet PanSTARRS (discovered June 2011) is named for the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) in Hawaii.