Bruce Jakosky, a planetary scientist from the University of Colorado Boulder, led NASA's expedition using the MAVEN spacecraft to determine how much atmosphere Mars had lost in time. MAVEN stands for "Mars Atmosphere and Volatile Evolution Mission". The project successfully provided clues about the Red Planet's infancy stage.
Apparently, Mars was a warm, wet place. Thousands of years ago, it probably looked like a hot spring area. However, through various factors in space, it evolved into a cold, dry planet. Jakosky and his team explain just how Mars lost all of its water basins, which are also signs of life.
According to Science News, the researchers measured and compared the amount of two argon isotopes at varying altitudes in the Martian atmosphere. Based on the collected data, they figured out that Mars could have lost about two-thirds already of its argon gas. Moreover, the scientists claim that the majority of carbon dioxide in the Red Planet was also ejected into the void black space.
The reason, per the study, was strong solar wind and radiation. For the record, argon is the most abundant element in the Earth's crust and the third most dominant gas in the atmosphere. Well, why do they want to know about the previous Martian atmosphere?
Per Science Daily, a thicker atmosphere with carbon dioxide and other greenhouse gasses could have supported life in the planet. It may have insulated the early Mars and kept it within the right temperature to host liquid water. To illustrate, Earth would have been a barren place without the ozone layer. Jakosky, who is also a professor at the Laboratory for Atmospheric and Space Physics, said that the current argon loss in the Martian atmosphere is now at 65 percent.
The mission headed by the University of Colorado Boulder determined that "noble gasses" like argon cannot be removed by anything else other than a process called "sputtering". In it, ions attracted by the solar wind hit Mars at high speeds and physically strip its atmospheric gas inch by inch. Meanwhile, carbon dioxide is of great interest too due to its abundance in Mars and its efficiency to retain heat and warm the planet.
