Comet Lovejoy's tail offers scientists a few surprises
Scientists have snapped rare images of the comet Lovejoy's rapidly changing tail. Using the Subaru Telescope in Japan, researchers from the National Astronomical Observatory of Japan, Stony Brook University and Tsuru University in Japan found that extreme, short-term changes took place in the tail of the comet - visible shifts that occurred in just 20 minutes. Stony Brook's Jin Koda, the principal investigator the night the images were shot, wasn't even focused on Lovejoy initially. But since he knew the comet was in the in the sky that night, his team started snapping images with the telescope's wide-field prime-focus Suprime-Cam for "educational and outreach purposes." "The single image from the previous night revealed such delicate details along the tail it inspired us further to take a series of images on the following night," Koda said. "As we analyzed the images, we realized that the tail was displaying rapid motion in a matter of only a few minutes! It was just incredible!" The plasma tail of a comet forms when gas molecules and atoms coming out from the comet encounter the solar wind, which consists of charged particles constantly sweeping out from the sun. These interactions with solar wind can affect the behavior and appearance of a comet's tail, though the reason for such changes is poorly understood. Lovejoy has for the past few weeks been putting on a show in the sky. Its green colors were so bright in late January that sky watchers could see it with their naked eye.