Researchers say that, about 4 billion years ago, new maps of water in the atmosphere of Mars reveal that the Red Planet might once have had enough to cover up to a fifth of the planet. There’s a possibility, that the water would have formed an ocean occupying almost half of Mars’ northern hemisphere, in some regions reaching depths greater than a mile (1.6 kilometers).
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.” said Geronimo Villanueva, first author of the paper and scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
So, where was this water on Mars?
Based on the surface of Mars today, the researchers say a likely location for this water would be in Mars’ Northern Plains, considered a good candidate because of the low-lying ground. An ancient ocean there would have covered 19 percent of the planet’s surface. By comparison, the Atlantic Ocean occupies 17 percent of Earth’s surface.
According to Michael Mumma, a senior scientist at NASA Goddard,
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.
The study is based on detailed observations made at the European Southern Observatory’s Very Large Telescope in Chile, and the W.M. Keck Observatory and NASA Infrared Telescope Facility in Hawaii. With these powerful instruments, the researchers distinguished the chemical signatures of two slightly different forms of water in Mars’ atmosphere. One is the familiar H2O. The other is HDO, a naturally occurring variation in which one hydrogen is replaced by a heavier form, called deuterium.
Since deuterated water is heavier than normal water, it behaves differently by comparing the ratio of HDO to H2O in water on Mars today and comparing it with the ratio in water trapped in a Mars meteorite dating from about 4.5 billion years ago, scientists can measure the subsequent atmospheric changes and determine how much water has escaped into space.
As an afterthought, the research published on March 5, 2015 says that a primitive ocean on Mars held more water than Earth’s Arctic Ocean. Most of the water – 87 percent – escaped into space, according to the scientists. Hence, they suggest the Red Planet could still possess substantial underground reservoirs of water.
via Mother Nature Network