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
A Planet Called Treason A Planet Called Treason A Planet Called Treason (1979) is a science fiction novel by Orson Scott Card. It was originally published by St Martin's Press and Dell Publishing Co. After being heavily revised, the book was republished under the title Treason (1988) by St. Martin's Press. The premise of this novel is the banishment to the seemingly metal-poor planet Treason of a group of people who attempted to create rule by an intellectual elite. The novel centers on the descendants of these anti-democratic thinkers who remain imprisoned on the planet. Through the ages, these descendants have formed nations which