Learn about the tenuous and highly variable atmosphere of Mercury, composed of hydrogen, helium, oxygen, sodium, calcium, potassium and water vapor. Find out how it originates from the Solar wind or the planetary crust, and how it varies with solar light and geographical location.

Learn about Mercury's thin and tenuous atmosphere, composed of atoms from the solar wind and the surface, and its polar ice deposits. Explore how Mercury's magnetic field and magnetosphere protect it from the Sun's influence.

Mercury has no atmosphere to retain heat or protect it from solar radiation. It has a thin exosphere made of atoms blasted off the surface by the solar wind and meteoroids.

Learn about Mercury's bulk parameters, orbital parameters, observational parameters, magnetosphere, and atmosphere. Mercury's atmosphere is extremely thin and tenuous, composed mainly of sodium and potassium ions.

Mercury has a thin atmosphere of sodium, oxygen, hydrogen, and helium, with trace amounts of other gases. Its surface is heavily cratered and has no magnetic field or atmosphere to protect it from the Sun's radiation.

Mercury, the innermost planet of the solar system and the eighth in size and mass. Its closeness to the Sun and its smallness make it the most elusive of the planets visible to the unaided eye.

Mercury has no atmosphere to trap heat or protect it from impacts, so its surface is very cold or very hot and cratered. Learn more about the innermost planet in our solar system, its orbit, rotation, and missions.

Learn about Mercury's surface, interior, magnetic field, and atmosphere, which is extremely thin and has pressure one-quadrillionth that on Earth. Find out how scientists study Mercury and why it is important for understanding rocky planets.

Learn about Mercury's temperature, size, surface, magnetic field, orbit and more. Find out how Mercury's atmosphere is too thin to retain heat or water, and why it has ice at its poles.