During the formation of the solar system, several heavenly bodies share the same ratio of similar elements of the atmosphere. Over the years, things have changed, which is a natural process, part of the ever-evolving nature of the universe.

Currently, the earth’s atmosphere is 78% nitrogen, 1% oxygen, 0.9% argon and 0.03% carbon dioxide, an apparent perfect ratio for life. However, it didn’t always seem that way. According to researchers, one of them being Professor Ian, member of Adelaide University and John Harrison, University of Arizona, levels of oxygen in the atmosphere in pre-historic times averaged between 30 to 35 percent.

Atmospheres can be altered in several manners, sometimes it leaps off in a huge chunk. In thermal scape such as hydro-dynamic escape, the gases in the atmosphere become too hot from the intense heat of the sun and evaporate away. Atmosphere can be released more slowly via non-thermal processes. This behavior is similar to when molecules bounce off each other, dispersing atoms into space.

Sometimes, the atmosphere is blasted into space from the collision of asteroids and comets. Mars, one of our closest neighbors, holds some of the most prevailing mysteries simply because it is similar to earth, yet so divergent. Mar’s atmosphere is over 95% carbon dioxide. So what happened to it?

Mars lost most of its atmosphere 3.8 billion years ago. According to the encyclopedia of paleoclimatology and ancient environments, Mars is said to have lost over 90% of its atmosphere over time. Mars is smaller compared to earth with less mass hence less gravitational pull on the atmosphere. For this reason, it is easier for the atmosphere to evaporate into space. Some of it was cleared by solar wind while some of it was flung into space by the clash of meteorites, according to a study published in a journal of science.

Could the same happen to earth?

It already did. Earth is a bit different. Earth is wrapped up in a magnetic shield that protects it from the sun’s damaging solar winds. Therefore, earth has not eroded as much as other planets. However, it does not mean that earth is resistant. A study published in the journal Icarus suggests that thousands of collisions from space rocks expelled most of earth’s atmosphere 4.5 billion years ago. This was in the past; nonetheless, we are still losing our atmosphere at a lesser rate.

The magnetic shield protects us from damaging solar winds. It also exudes tiny amounts of the atmosphere into space. As the sun’s energy is absorbed, it is channeled through the upper atmosphere, where it hears up some of the molecules and leaves the earth’s atmosphere the same way it got in. So, earth is losing its atmosphere faster than the rate neighboring planets are losing theirs. This is according to research presented at the European geosciences union general assembly meeting in 2013.