A Minute atmoshpere is a temporary atmosphere composed of Helium and Sodium from the solar wind of the sun.
Mercury has a highly variable atmosphere (surface-bound exosphere) containing hydrogen, helium, oxygen, sodium, calcium, potassium and water vapor, and a combined pressure level of about 10−14 bar. 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 when the Mariner 10 spacecraft discovered only a tenuous exosphere.