Of all the planets in the solar system, Mercury has the lightest atmosphere. In fact, its atmosphere is lighter even than that of Mars. This is due to its size, its weak magnetic field as well as its proximity to the Sun. Furthermore, Mercury is the smallest and least massive of the eight planets and orbits a few million miles from the Sun. they are the atmospheric components of Mercury.
Atmospheric components
The rocky planet is constantly bombarded by the solar wind. Likewise, fast blowing winds constantly attack Mercury and tear off almost all of its gaseous envelope. Charged particles collide with the surface of the planet. Both the particles themselves and the heat they produce push the material upward from the planet’s outer layer, sending it flying through the air.
In addition, the heavier atoms return to the surface, while the lighter ones are affected by the gravity of the solar photons. The result of this is a thin atmosphere known as the exosphere. On the other hand, the atmosphere is composed of 42% oxygen, 29% sodium, 22% hydrogen, 6% helium, 0.5% calcium and another 0.5% potassium. Traces of other compounds have also been found, such as carbon dioxide, magnesium, water, nitrogen, and other noble gases.
This weak atmosphere is incompatible with the solar wind. For this reason, this vestige of atmosphere is not fixed, but disappears with the solar wind. Hydrogen and helium come from the capture of these gases by the magnetosphere. Likewise, the presence of other components is explained by the release of these compounds by the planet’s crust due to the impact of photons and high-energy ions.
On the other hand, the presence of water and carbon dioxide are probably due to the impacts of comets in the unlit part of the planet, although they sublimate quickly as soon as they are illuminated. In addition, scientists do not rule out that there are regions that are permanently in the shade, such as deep craters or polar areas.
