Studies lead to believe that Mars had more water than we originally believed.
Artist’s impression of how Mars may have looked about four billion years ago, with an ocean occupying almost half of the northern hemisphere. Maps of the isotopic composition of water in the atmosphere of Mars have shown just how much of the planet’s water has been lost to space, and indicate an early ocean on Mars with more water than the Atlantic Ocean on Earth.
Villanueva and his team mapped Mars for six years (three martian years) and found surprising variations: microclimates and seasonal changes. They found that atmospheric water near the poles was enriched in HDO by a factor of seven compared to water on Earth, and polar ice enriched by a factor of eight.
Together these suggest that the planet lost 6.5 times more water than is currently in the ice caps, making an ocean of at least 200 million km3 in the Noachian period. If this had occupied the low-lying Northern Plains, comparable in area to the Atlantic, it would have been more than 1.9km deep in places.
This work highlights the power of ground-based telescopes to study planetary processes. It also suggests that Mars may have had a much longer period as a wet and potentially habitable planet.
Source: Daily Galaxy