![]() ![]() A major focus of recent research has been on the interpretation of Jovian auroral emissions at infrared, ultraviolet, and X-ray wavelengths. ![]() The ionospheres of the giant planets Jupiter, Saturn, Uranus, and Neptune are reviewed in light of Pioneer, Voyager, Galileo, and groundbased infrared observations. A brief account on recent development in the area of laboratory studies of X-ray production is also provided. Processes of production of solar system X-rays are discussed and an overview is provided of the main source mechanisms of X-ray production at each object. X-rays from the Galilean satellites and the IPT are mostly driven by impact of Jovian magnetospheric particles.This paper reviews studies of the soft X-ray emission from the solar system bodies, excluding the Sun. The spectral characteristics of X-ray emission from comets, the heliosphere, the geocorona, and the Martian halo are quite similar, but they appear to be quite different from those of Jovian auroral X-rays. The non-auroral X-ray emissions from Jupiter, Saturn, and Earth, those from the disk of Mars, Venus, and Moon, and from the rings of Saturn, are mainly produced by scattering of solar X-rays. The first soft (0.1–2 keV) X-ray observation of Earth's aurora by Chandra shows that it is highly variable. X-rays have been detected from Saturn's disk, but no convincing evidence of an X-ray aurora has been observed. Progress in modeling X-ray emission, laboratory studies of X-ray production, and theoretical calculations of cross-sections, have all contributed to our understanding of processes that produce X-rays from the solar system bodies.At Jupiter and Earth, both auroral and non-auroral disk X-ray emissions have been observed. The advent of higher-resolution X-ray spectroscopy with the Chandra and XMM-Newton X-ray observatories has been of great benefit in advancing the field of planetary X-ray astronomy. ![]() 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 (IPT), the rings of Saturn, the coronae (exospheres) of Earth and Mars, and the heliosphere. Several new solar system objects are now known to shine in X-rays at energies below 2 keV. During the last few years our knowledge about the X-ray emission from bodies within the solar system has significantly improved. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |