Wet World

Catherine Cloutier | Globe Staff
Tuesday, September 29, 2015

Taylor Perron talks to the Boston Globe about the new findings from NASA indicating that Mars may not be the arid planet it was once thought to be.

Read this story at the Boston Globe

New findings from NASA indicate that Mars may not be the arid planet it was once thought to be.

Scientists unveiled research Monday, published in the journal Nature Geoscience, detailing likely evidence of liquid water on Mars. They called it a “much more dynamic and complex planet.”

The Globe spoke with J. Taylor Perron, an associate professor of geology in MIT’s Department of Earth, Atmospheric, and Planetary Sciences, about the findings.

So what do these findings mean exactly?

The research offers indirect evidence of liquid water on Mars. While no testing was done on the surface, scientists found water in salt molecules on the surface of the planet in readings from an orbiting spacecraft.

The announcement is not entirely surprising, said Perron. Research from the same scientists in 2011 foreshadowed these findings. The scientists believed liquid water played a role in the dark streaks descending along the slopes of craters, canyons, and mountains that appeared in photographs of the planet. The streaks — called recurrent slope linae — appeared during the spring, lengthened during the summer, and then faded when temperatures decreased.

The research is “tantalizing,” said Perron. “It gives us a glimpse of what might be happening on the shallow surface of Mars.”

Haven’t I heard this before?

This is not the first time scientists have released findings of water on Mars, said Perron, but in past cases, they found evidence of water a long time ago. Perron said his own research has examined an ancient ocean and ancient rivers and water pathways on the planet.

What makes this most recent announcement important is that it finds that water is likely flowing at the present time.

“The novelty about this announcement is there’s evidence of salty water flows happening now,” said Perron. “It’s probably the best evidence we have so far.”

Scientists believed the planet’s ancient water was frozen below the planet’s crust. This research “suggests that water is close enough to surface that it can lead to observable change,” said Perron.

Does this mean there might be life on Mars?

On Earth, life requires liquid water. The prospect of water, and its potential life-giving properties, has been a major focus in the study of Mars, said Perron. But the results don’t necessarily mean there’s life on the planet.

“As far as life goes, we still have to resort to speculation,” said Perron. “But it does check off one box that we think life requires.”

The liquid water that scientists detected is very salty, which might be too harsh for many organisms, said Perron. But some types of microscopic organisms, including certain types of bacteria, can survive in salty environments, he said.

How does this affect sending astronauts to Mars?

During a news conference Monday, a NASA scientist said the water would be a useful resource for further exploration.

One reason for this relates to all-too-earthly budgetary concerns. The most expensive consideration in sending space missions to orbit or another planet is weight, said Perron. Having access to a water source on Mars would drastically reduce the amount of weight the mission would need to carry.

“If we were to run a manned Mars mission, a source of water would be essential,” he said. “Knowing where to find that water is a prerequisite for that kind of mission.”

The new findings not only offer evidence of this water, but they also identify places where this water is close to the planet’s surface. During a mission, astronauts would need to be able to easily access this water supply, Perron said.

What’s next?

With each exciting observation from orbit, it renews the determination to get astrobiologists on the ground, said Perron.

He predicted that areas where water has been found will become areas of special interest for future exploration.