Atmosphere of Mercury Atmosphere of Mercury Mercury has a very tenuous and highly variable atmosphere (surface-bound exosphere) containing hydrogen, helium, oxygen, sodium, calcium, potassium and water vapor, with a combined pressure level of about 10 bar (1 nPa). The exospheric species originate either from the Solar wind or from the planetary crust. Solar light pushes the atmospheric gases away from the Sun, creating a comet-like tail behind the planet. The existence of a Mercurian atmosphere had been contentious before 1974, although by that time a consensus had formed that Mercury, like the Moon, lacked any substantial atmosphere. This conclusion was confirmed in 1974
Atmosphere of Jupiter relative to the other latitudes. The South Tropical Region includes the South Equatorial Belt (SEB) and the South Tropical Zone. It is by far the most active region the planet, as it is home to its strongest retrograde jet stream. The SEB is usually the broadest, darkest belt on Jupiter; it is sometimes split by a zone (the SEBZ), and can fade entirely every 3 to 15 years before reappearing in what is known as an SEB Revival cycle. A period of weeks or months following the belt's disappearance, a white spot forms and erupts dark brownish material which is