Curiosity rover extends period of possible life formation on Mars
Curiosity landed on Mars nearly 5 years ago, and since then it has done quite a bit of research that has interested researchers. Dr. Jens Frydenvang is a professor at the Neils Bohr Institute at the University of Copenhagen in Denmark that works on the Curiosity rover. His team has been finding unexpected discoveries since the rover landed on Gale crater in August 2012.
The discovery
NASA’s Curiosity rover provided us with another surprise in June. Searching the Gale crater for evidence of previously existing body of water, the rover found cracks in the planet’s surface rich with
deposits of silica. The fractures in the bedrock of the ancient dried up lake are believed to be from the underground remnants of the lake trickling onto the surface and causing erosion. The silica, Dr. Frydenvang believes, is the residue of rocks in the underground water or is deposited from the surface via water flow.
[endif]--Curiosity’s ChemCam identified the residue as silica,
which is what Martian rocks are made of. This finding could prove that Mars had water for longer than scientists previously thought.
ChemCam
The ChemCam is a pretty neat tool for the Curiosity team. Gathering information about the chemical composition of rocks previously required physically contacting them to scrape away layers of dust to expose the surface and then carefully examining them with various tools. This process can take up to three days, and time is precious for the rovers. This was something that desperately needed to be improved on the future travelers.
Curiosity’s ChemCam uses a series of lasers instead, which is way cooler, but most importantly, more efficient as well. The lasers can reach up to 25 feet, which makes it much easier to target rocks to study. The first series of pulses is shot at a rock to remove the outer layer of dust, while the second series actually vaporizes the outer surface of the rock. When the second laser hits the rock, the electrons in the rock get excited and emit light energy, like a spark. Different elements result in different color of spark, and the spectrometer in the ChemCam allows researchers to identify which elements they are seeing.
The ChemCam revealed that silica was the deposited material in the Gale Crater bedrock, which lead Dr. Frydenvang to believe that it was ancient silica rocks and water sources that left the halos on the lake floor.
Why is this important?
The discovery gives us a little bit more insight on the search for life on extraterrestrial planets. Dr. Frydenvang’s hypothesis that the underground water sources deposited the silica would mean that the lakes would could be older than previously thought, because water running through the subsurface of the Gale Crater long after the lakes had evaporated would have deposited the silica into much younger cracks in the lake floor that we currently observe. Frydenvang believes the Gale crater lake could be as old as 3.8 billion years old, which would require us to alter our idea of when life may have evolved on Mars.
“Given that we are exploring what was a definite habitable environment, the big question we’re still trying to answer, apart from looking for signs of actual life, is for how long this habitable environment lasted – and hence, how much time life had available to form before Mars turned into the arid and inhospitable planet we see today,” he said.
NASA’s MAVEN spacecraft, which is orbiting the red planet, is also studying how water was lost over millions of years. This research could provide valuable insight on how atmospheric conditions can affect a planet’s ability to retain water.
“I’m not on the MAVEN mission, but the early results do suggest that solar winds would effectively strip the atmosphere from Mars over time,” Frydenvang said. “The resulting lowering pressure would leave Mars unable to maintain surface water. A similar thing hasn’t happened to Earth because our magnetic field shields us, and the atmosphere, from the solar winds.”
Life on Mars
Given that this finding proves that water has existed on Mars for longer than we thought, it expands the window of time that life could have formed on the planet. Mars is currently theorized to be 4.5 billion years old, which is about the same as Earth. Frydenvang’s research shows that the lake at Gale crater could be up to 3.8 billion years old, which means that the conditions for life came to be in the relatively short 700 million years. Researchers now want to find out how long it would take for life to actually develop.
“This study ties into this work by showing that we had liquid groundwater running through the subsurface long after the lakes disappeared. What we are actively exploring now however, is filling in the ‘middle part,’” Frydenvang said. “In sum, how long did the lakes actually exist?”
Curiosity continues to pique our interest, and the research team expects to look further into the many discoveries the heroic little Martian rover acquires for us.
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