Q&A: Chandra Mission
If you pointed Chandra at Earth, what would it see?
On the daylight side, Chandra would see lots of X-rays reflected
from the atmosphere. These X-rays are produced by collisions of
high-energy particles from the Sun with the atmosphere. X-rays
from the radiation belts that surround the Earth would be
detected. In any event, the daylight Earth is too bright to
observe with Chandra. The X-rays would swamp the detectors and
possibly damage them. The nighttime X-ray flux would be would be
less intense, but the radiation belt X-rays would still pose a
problem.