Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. In this digital picture, pixel brightness corresponds to x-ray intensity. It's true that the dark lunar face is in shadow and so is not reflecting solar x-rays . Still, the few x-ray photons which seem to come from the moon's dark half are currently thought to be caused by energetic particles in the solar wind bombarding the lunar surface.
Specific rights apply .