Martian Atmosphere Lost To Space, A New Study Reveals

Mars could have sustained life billions of years ago if its atmosphere had not been lost to space. This is the revelation of the new study conducted by scientists working with NASA's MAVEN spacecraft.

The new study was printed in Science on March 31, 2017. It was led by Bruce Jakosky, the principal investigator for the Mars Atmosphere and Volatile Evolution Mission (MAVEN), the University of Colorado at Boulder, and other colleagues. The study could help in understanding the mystery of Mars' environments, according to Space Flight Insider.

"We've determined that most of the gas ever present in the Mars atmosphere has been lost to space," Jakosky said. Its atmosphere was taken away by solar wind and radiation that turned Mars into a frosty, dry planet today. The team discovered that about 65 percent of the argon, which is a gas that never chemically reacts with other elements, in the Martian atmosphere has been lost to space.

In the study, the scientists investigated two different isotopes of argon, namely the lighter argon-36 and the heavier argon-38. Argon-36 has about 18 neutrons in its nucleus, and argon-38 contains 20 neutrons.

The team discovered that argon-36 is more abundant than argon-38, which is the heavier counterpart. This means that argon-36 is more vulnerable to be taken away from the atmosphere by solar winds and ultraviolet rays. The researchers also found that the concentrations of the two argon isotopes indicated that 66 percent of Mars' argon had been lost since Mars formed.

The study also indicated that the Martian atmosphere was thick with carbon dioxide. This could have been the same atmospheric pressure of air on Earth at sea level, according to CBS News.

Jakosky said that the disappearance of gas to space might have played a significant role in changing the climate of Mars over time. He further said that the vanishing carbon dioxide from Mars could tell why the Martian surface could have gone from habitable in the past to not being able to sustain life today. He added that they also discovered some processes that could help them understand the habitability of planets around the stars.