X-ray emission from the solar system bodies: connection with solar X-rays and solar wind

Abstract

Today the field of planetary X-rays is very dynamic and in the forefront of new research. Apart from the Sun, the known X-ray emitters now include planets (Venus, Earth, Mars, Jupiter, and Saturn), planetary satellites (Moon, Io, Europa, and Ganymede), all active comets, the Io plasma torus, the rings of Saturn, the coronae (exospheres) of Earth, Mars and Venus, and the heliosphere. Scattering of solar X-rays mainly produces the non-auroral X-ray emissions from Jupiter, Saturn, and Earth, those from the disk of Mars and Venus, from the surface of the Moon, and from the rings of Saturn. The X-ray emission from comets, the heliosphere, the geocorona, and the Martian and Venusian exospheres are all largely produced in charge exchange collision between highly ionized minor heavy ions in the solar wind and gaseous neutral species in the bodies' atmosphere-a process known as solar wind charge exchange (SWCX). Thus, both, the solar radiation and out-flowing plasma from the Sun (solar wind) power the production of X-ray emission from solar system bodies. A brief overview on X-rays from the solar system bodies and their connection with solar X-rays and solar wind is presented in this paper.