If the atmosphere on Mars is missing, where did it go? It's a question scientists have tried to answer for years and it looks like they found it. Based on a new study, the Martian atmosphere was lost in space.

Scientists use the data from NASA's Mars Atmosphere and Volatile Evolution Mission (MAVEN) satellite and NASA's Mars Curiosity Rover to determine that there used to be an Earth-like gas or atmosphere on Mars. However, the composition is different compared to what is found on Earth. Experts say that the Martian atmosphere could be composed of excessive amounts of carbon dioxide.

"We're in the process of tallying up what the total amount removed was, but I'm going to guess right now that the amount of atmosphere that was present was about as thick as the Earth's atmosphere - about one or two bars of gas," Bruce Jakosky from the University of Colorado in Boulder, said in an interview with BBC. "The bulk of that -- maybe 80-90% -- has been lost to space."

Maven has been studying Martian's upper atmosphere since 2014. Scientists used the data from MAVEN for a study on the gas argon on Mars. Experts say that gas argon exists just a few parts per million. This element is also very instructive and does not react to other particles.

The properties made scientists conclude that the only way to lose them is if they were dragged into space. Solar winds could have caused the motion that leads to the entire atmosphere being lost in space.

In over 4.5 billion years, too much of Mar's gaseous atmosphere had been lost. Not only that, the planet is continuously losing parts of what remains of its atmosphere into space, according to Popular Science.

"What we've seen from the argon measurements is that about two-thirds of the argon that was ever in the atmosphere have been lost to space," Bruce Jakosky, principal investigator for MAVEN, added.

A planet's atmosphere has a huge part to play in order to assess to the habitability of a celestial object.

"This discovery is a significant step toward unraveling the mystery of Mars' past environments," Elsayed Talaat, MAVEN Program Scientist, at NASA Headquarters in Washington said in a statement. "In a broader context, this information teaches us about the processes that can change a planet's habitability over time."