Today is

The Chandra X-Ray Observatory Gallery

<< 10/12 < > This remarkable Chandra image gave scientists their first look at X-rays from Mars. In the sparse upper atmosphere of Mars, about 120 (75 miles) kilometers above its surface, the observed X-rays are produced by fluorescent radiation from oxygen atoms. X-radiation from the Sun impacts oxygen atoms, knock electrons out of the inner parts of their electron clouds, and excite the atoms to a higher energy level in the process. The atoms almost immediately return to their lower energy state and may emit a fluorescent X-ray in this process with an energy characteristic of the atom involved - oxygen in this case. A similar process involving ultraviolet light produces the visible light from fluorescent lamps. Credit: NASA/CXC/MPE/K.Dennerl et al.

     To the Top