Comet Elenin Has Been Lost to View Because of Its Faintness

In the beginning of its detection comet Elenin received quite a bit of attention from astronomers because its orbit would take it quite close to Earth, within 22 million miles (35 million kilometers), on October 16, 2011. Even as recently as August 19, the comet was brighter than predicted, as observed and photographed by amateur astronomers in Australia, notably Michael Mattiazzo. After that occured sun’s coronal mass ejection (CME). The next day the comet had dropped half a magnitude in brightness, and has continued to drop, despite the icy body getting closer to the sun. Apparently the comet is disintegrating, as sometimes happens when comets pass too close to the sun.

On September 10 the comet passed its perihelion, a phase marking its closest approach to the sun, at a distance of 44.8 million miles (72.1 million km). Since then, the comet has been lost to view because of its faintness and its proximity to the sun in the sky. If all had gone as planned, the comet would be moving into the field of view of one of the cameras on NASA’s Solar and Heliospheric Observatory (SOHO) satellite on September 23. Elenin will pass Zaniah on September 25 and Mercury on September 27, before moving out of SOHO’s field of view on September 29. At this point, no one can predict exactly what we will see through SOHO’s eyes in the coming week, but everyone will have the chance to watch using one of NASA’s brightest eyes on the solar system. If comet Elenin survives its close encounter with the sun, it will become visible in morning twilight towards the end of the first week of October.