The Earth, the Moon, Mercury, Saturn and Its Rings, and Asteroids

The planets Earth and Saturn have dense atmosphere and strong intrinsic magnetic field and hence a sturdy magnetosphere. Therefore, both of these planets are expected to have X-rays produced in their atmosphere due to resonant and fluorescent scattering of solar X-rays as well as charge particle precipitation in the auroral/polar regions. Though auroral X-rays have been seen on Earth for several decades, they are yet to be unambiguously observed at Saturn. The rings of Saturn, the Moon (Earth’s moon), Mercury, and asteroids are airless bodies and thus shine in X-rays due to fluorescent scattering of solar X-rays by elements on the surface – thereby providing vital information on the elementals and their distribution on the surface. This chapter provides a brief review of X-ray emissions from the Earth, and in particular its aurora, from the Moon, Mercury, Saturn and its rings, and asteroids.