The Earth in Gamma Rays

This is a false-color image of the Earth in three gamma-ray energy bands, analogous to the colors red (lower energy), green (mid energy) and blue (higher energy) in the visible spectrum. The lower right shows a composit image.(Image credit: NASA/CGRO/EGRET/ Dirk Petry)

But Petry created this gamma-ray Earth image to better understand the impact of "local" cosmic-ray and gamma-ray interactions on an upcoming NASA mission called GLAST, the Gamma-ray Large Area Space Telescope. GLAST is planned for launch in 2007. Its main instrument, the Large Area Telescope, is essentially EGRET's successor.