New Mercury Papers

Comet Mercury…..this image taken at Boston University’s station at the McDonald Observatory in Ft. Davis, Texas, on May 30, 2007, reveals a remarkably long (~2° ) sodium tail of Mercury. At the time the image was taken, Mercury was only 5° above the western horizon (a smeared image of a tree can be seen in the foreground). The planet is hidden behind an occulting mask at the center of the picture (at this plate scale the planet would only be 0.1 pixels in diameter). The inset image was taken a year earlier with the 3.7m AEOS telescope on Maui when Mercury was at a similar orbital phase. At this greatly magnified scale, the source regions of the sodium atoms can be seen to be concentrated at high latitudes on the planet. Detailed study of this and other images will yield information on the time history of the production rate of sodium atoms at Mercury. Photo credit: Jody Wilson and Carl Schmidt, Center for Space Physics, Boston University.