Thanks to observations of orbiters and also robotic surface explorers such as the Curiosity and Perseverance rovers, we already know that liquid water flowed across the surface of Mars in the distant past. However, that changed about 3.5 billion years ago, when the Red Planet lost its magnetic field that helped hold water. Now, a new study, led by Zhen Tian of Washington University, suggests that our neighbor may be too small to keep large amounts of water on its surface.
- The water that Mars lost may not have gone into space, but into the crust
- Saltwater is “erasing” records of Mars’ past , marked in minerals
Water from Mars is escaping space—and dust storms are to blame
Several remote sensing studies and analyzes of meteorites from Mars previously conducted indicate that the planet was once rich in water , and this has been reinforced by more recent evidence. However, what we see today is a dry and arid planet. Kun Wang, an assistant professor and one of the study’s authors, explains that the fate of Mars was decided from the start. “There’s probably a limit on the size requirements of rocky planets to retain enough water to allow for habitability and plate tectonics,” he said — and perhaps that limit is higher than Mars is.