NASA: Mars may have had an ocean comparable to Earth's Atlantic
Azadeh Ansari, CNN
The scientists compared the ratio of H2O to HDO in Mars' atmosphere today to the ratio of the two molecules trapped inside a Mars meteorite, a stone that broke off from Mars -- perhaps when an asteroid hit -- and landed on Earth some 4.5 billion years ago.
Evidence of water on Mars
Evidence of water on Mars 01:31
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They were able to determine how much that ratio had changed over time and estimate how much water has disappeared from Mars -- about 87%.
The findings indicate that the Red Planet could have had its fair share of blue waters, possibly even yielding an ocean. According to NASA, there might have been enough water to cover up to 20% of Mars' surface.
That would amount to an ocean proportionally larger than the Atlantic on Earth.
"This ocean had a maximum depth of around 5,000 feet or around one mile deep," said Villanueva.
NASA scientists say that much of this water loss happened over billions of years, along with a loss of atmosphere. And as the planet's atmospheric pressure dropped, it was harder for water to stay in liquid form. Heat also contributed to its evaporation.
As a result, the remaining primeval ocean water continued to move toward the poles, where it eventually froze.
"With Mars losing that much water, the planet was very likely wet for a longer period of time than was previously thought, suggesting it might have been habitable for longer," said Mumma.
CNN's Ben Brumfield contributed to this report.
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