Where was Mars' water lost?

Jan 26, 2007 07:54 GMT  ·  By

Mars may hold large underground reservoirs of water and carbon dioxide that once formed the planet's ancient atmosphere, new research suggests.

Could Mars have had life on its surface in the past?

Data from the European Space Agency's Mars Express orbiter signal that the planet could hold large underground amounts of water and carbon dioxide.

A team at the Swedish Institute of Space Physics found that, of the water and carbon dioxide that once existed on the planet, solar wind (a rapid flow of charged particles expelled by the sun in the Solar System) must have taken off only a small amount over the past 3.5 billion years.

Thus, vast quantities of water and carbon dioxide may still exist below the Martian surface. "Further research into the planet's subsurface and atmosphere could reveal critical information about Mars's climate," added the Swedish team. "Knowing [more about the ancient Martian climate], we could speculate whether or not conditions were suitable for any complex structures [like organic materials] to develop."

"The question is thus directly related to the question of Mars's habitability."

"The origin of life, in my opinion, is the most important question the modern science is facing," said Stas Barabash, team's leader.

Researches pointed that Mars once had a much warmer and wetter atmosphere. The former water abundance is indicated by geological traits on the planet, but there's a mystery about what happened with this water.

Besides the theory of the underground deposits, another one exists, supposing that a cosmic collision must have taken off much of the Martian atmosphere. Solar wind was also put amongst the culpable factors which left Mars without water. "I'm a plasma physicist so I really like the last one," said Barabash, a professor of experimental space physics. "But our last study shows that escape [of water and carbon dioxide] from this channel is not as intense as we thought before, and that's a very big puzzle."

Solving the mystery of Mars' water loss requires time to solve. "Recent measurements both from Mars Express and from Mars Global Surveyor suggest that we have not yet even described all of the loss processes at the present epoch," said Bruce Jakosky, from the Laboratory for Atmospheric and Space Physics at the University of Colorado. "This means that we cannot yet determine the total loss rate today, let alone be able to extrapolate to earlier epochs."

"It's possible that solar wind is far more complex than we think," added Barabash. "So we have to explore other escape channels which are also associated with the solar wind."