Mars has largely remained unchanged for the past 4 billion years, give or take. The Martian planet is currently cold and dry, thick with carbon dioxide and thin on atmosphere—about 1 percent as thick as that of Earth, Space.com said. And scientists believe it may have gotten that way very quickly, likely through external factors.
Through data collected by NASA’s Curiosity rover, along with previous studies of Martian meteorites, scientists believe Mars lost its atmosphere in a hurry, not all that long after forming either. Following its violent formation around 4.5 billion years ago, researchers believe the planet was bombarded by space debris about 3.5-4 billion years ago, causing the atmosphere to essentially disappear.
With the latest data, scientists have concluded that Mars may have once been much warmer, and possibly wetter, meaning life could have existed. But that same data suggests life on the planet today does not exist because the planet lacks methane. Here on Earth, methane is produced almost entirely because of living organisms. “There’s not much methane [on Mars],” said chemist Paul Mahaffy.
So while the data is giving scientists a clearer picture of what Mars may have been like back in the day, it’s also helping researchers understand why it is the way it is right now. Cold, dry, and without life. But it may not have always been that way, and scientists want to better determine the process that lead to the planet’s thin atmosphere. If only we could go back 4.5 billion years to see Mars in its heyday.