We humans on Earth are very lucky, because we have an atmosphere that is about 300 miles thick. Our atmosphere contains the gasses we breath, and the atmosphere protects us from the harsh radiation and warmth coming from the Sun. However, some planets do not have atmospheres remotely similar to ours. For instance, does Mercury have an atmosphere?
Unlike our thick atmosphere, Mercury has a very thin atmosphere. In fact, Mercury’s atmosphere is so thin that is barely exists. The atmosphere is calculated as the thinnest atmosphere of all the planets in our Solar System.
Scientists are still exploring and learning about Mercury’s atmosphere, but they have discovered a few things. Mercury has a low gravity and receives large gusts of solar winds from the nearby Sun. Earth’s atmosphere contains nitrogen, oxygen, argon, carbon dioxide, and a few other molecules. Mercury, on the other hand, contains hydrogen, helium, oxygen, sodium, calcium, potassium, and water.
The problem Mercury faces is that its atmosphere is in danger of being blown away by the powerful solar winds coming from the Sun. Scientists find that the molecules in the atmosphere are constantly being restored and replaced, so the atmosphere is never quite empty. Scientists suggest that dust and rocks kicked into the air by wind or meteorites may be giving the atmosphere its molecules, or solar winds could be kicking up dust and gas.
Mercury also has a magnetic field, and has two poles. While the magnetic field is nearly 150 times weaker than our own on Earth, this magnetic fields helps hold its atmosphere in place by reducing the impact of the solar winds. Gravity is the other force that helps hold the atmosphere’s gasses in place.
Thinking about Mercury’s atmosphere can be confusing, because we are used to having a stable atmosphere on which we can rely. Mercury is not like that. Instead, the atmosphere of Mercury is unstable and constantly shifting. As the atmosphere’s materials are being made, they are also being taken away at the uppermost layers due to solar winds. The composition of the atmosphere can also change as you move across the planet.
Therefore, when you are thinking about Mercury’s atmosphere, you should remember that it does have an atmosphere, but it is not similar to the atmosphere we know on Earth. Mercury’s atmosphere is constantly shifting, is consistently stripped and blown away by solar winds, and it is constantly replenishing itself. While Mercury does have an atmosphere, it is very thin and constantly trying to exist around Mercury.