Mars has clues to offer about its past, if you know where to look and what to look for.
Western Washington University assistant professor of Geology Melissa Rice, a member of NASA’s Curiosity rover science team, has collaborated with that team to publish new research from the rover’s findings in the journal “Science” about some of those clues from the planet’s surface.
As the most recent discoveries in September have shown, not only has water existed on Mars in the past, it exists there now in small amounts as flowing water as well. But the Curiosity team’s research is focused on breaking down a year’s worth of data sent back to earth from the Curiosity, specifically surrounding the discovery near Gale Crater at the base of Mount Sharp of a huge ancient lakebed and its rocks, and Rice is far more interested in the water that was on the planet billions of years ago than what is there now.
“We’re piecing together a story about what these rocks mean, and what they say about the environment in which they were formed,” Rice said. “We have found smaller lakebeds before, but what we found here were rocks that most likely formed in deltas, where a flowing body of water meets a still body of water.”
The rocks from the bottom of this lakebed are so ancient – about 3.8 to 3.3 billion years old – that most of Mount Sharp, a peak about the size of Mount Rainier, has grown and formed over the top of the lake since it went dry.
“Deltas take a long time to form, so water was running at that location for quite some time,” she said. “We’re not sure if water could have been there long enough for life to have taken root. And we’re trying to understand where that water came from to begin with – was it rainfall? Snowfall?”
Mars had a thicker atmosphere once, and it is clear that the Mars of 3.8 billion years ago far more closely resembled Earth today.
“What happened when all that water was there in Gale Crater? That’s what Curiosity is trying to find out,” she said.
Rice’s full article in Science is available at http://science.sciencemag.org/content/350/6257/aac7575.abstract. For more information, contact Melissa Rice at (360) 650-3592 or Melissa.firstname.lastname@example.org.
Photo caption: This photo, taken by Curiosity, shows the ancient lake bed stretching to the horizon, as Mount Sharp begins to loom in the background. The rocks in the foreground are more than 3 billion years old, and point to the existence there of a delta, where flowing water and still water meet. How long was this water on the surface, where did it come from, and did it support life? These are the questions Curiosity and its science team are still attempting to unravel. Image courtesy NASA.