About half of the red planet's northern hemisphere would have been cloaked in an ocean around 4 billion years ago, according to Geronimo Villanueva from NASA’s Goddard Space Flight Center. Lead author of the paper, Villanueva stated in a press release for ESO:
“Our study provides a solid estimate of how much water Mars once had, by determining how much water was lost to space. With this work, we can better understand the history of water on Mars.”
Two different forms of water were studied using ESO's imaginatively named Very Large Telescope and a number of other instruments: our familiar water (H2O) and semi-heavy water (HDO). By examining the ratio between these two types of water over a period of 6 Earth years, the team was able to calculate exactly how much water may have been lost from Mars' surface.
The conclusion? About the same amount that's in the Earth's Arctic Ocean.
Second author on the paper, Michael Mumma, said, “With Mars losing that much water, the planet was very likely wet for a longer period of time than previously thought, suggesting the planet might have been habitable for longer.”
Indeed, the lost ocean on Mars would have covered more of the red planet's surface (19%) than our own Atlantic Ocean does of Earth's (17%).
The finding underlines just how far modern astronomical technology has come. Co-author Ulli Kaeufl illustrated this, saying, "I am again overwhelmed by how much power there is in remote sensing on other planets using astronomical telescopes: we found an ancient ocean more than 100 million kilometres away!"
The study has major implications for astrobiologists; a more habitable ancient Mars means that there is an increased likelihood that we will find evidence of life on our neighbouring planet.
By Jon Fern
Follow @jfernwriter
Image: artswallpapers.net
