Martian water could have enough oxygen to support life

Deborah Netburn
Los Angeles Times

Modern-day Mars may be more hospitable to oxygen-breathing life than previously thought.

A new study suggests that salty water at or near the surface of the red planet could contain enough dissolved O2 to support oxygen-breathing microbes, and even more complex organisms such as sponges.

“Nobody thought of Mars as a place where aerobic respiration would work because there is so little oxygen in the atmosphere,” said Vlada Stamenkovic an Earth and planetary scientist at the Jet Propulsion Laboratory who led the work. “What we’re saying is it is possible that this planet that is so different from Earth could have given aerobic life a chance.”

As part of the report, Stamenkovic and his coauthors also identified which regions of Mars are most likely to contain brines with the greatest amounts of dissolved oxygen. This could help NASA and other space agencies plan where to send landers on future missions, they said.

The work was published Monday in Nature Geoscience.

On its surface, the planet Mars is not what you would consider a hospitable place for most Earthlings.

Here on Earth, 21 percent of our atmosphere is made up of oxygen – thanks to the abundance of plants and other organisms that create oxygen as a byproduct of photosynthesis.

The Martian atmosphere, on the other hand, is made up of just .145 percent oxygen, according to data collected by the Mars rovers.

In addition, Mars’ atmosphere is extremely thin – 160 times thinner than Earth’s atmosphere. In addition, the temperature at the surface frequently drops to minus 100, making it extremely difficult for liquid water to exist on the planet’s surface.

Pure liquid water would either freeze or evaporate away on Mars, but salty water, or brines, could remain in a liquid state at or just below the surface of the planet, the authors said. That’s because water mixed with salts has a lower freezing temperature than plain water.