According to NASA, approximately 4.3 billion years ago, Mars was much damper than now. Around 20 million cubic km of water was present on the red planet. According to scientists, the water was also present in the northern hemisphere’s Northern Plains in collective form. It led to the formation of an ocean covering 19% of surface of the planet, with a depth of up to a mile in places.

The amount of water on Mars was more than Earth’s Arctic Ocean. It is also expected that it could have occupied much of the planet’s surface than covered by Earth’s Atlantic Ocean. As per scientists, the quantity of water was 6.5 times more than what is present at the moment. And this shows that the planet lost much of its water, when it began drying up approximately 3.7 billion years ago.

“With this work, we can better understand the history of water on Mars. Our study provides a solid estimate of how much water Mars once had”, Geronimo Villanueva, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who led the study said in a statement.

He also said that the study will help scientists know about the history of water on Mars. In the study, the ratio of HDO to H2O in water on Mars was compared to the ratio of a Martian meteorite, which is 4.5 million years old.

Michael Mumma, a senior scientist at Goddard, said that since Mars lost great amount of water, the planet remained damp for a longer time than expected earlier.