Curiosity is earning its keep on the red planet, demonstrating the benefits of sending rovers to uninhabitable worlds. Its newest find may challenge the idea that Mars was always incapable of harboring life. Organic molecules were found in a sample of sedimentary rock just below the surface. These molecules include carbon and hydrogen, necessary ingredients for life though not a guarantee that life ever existed on the planet.
The Gale Crater was the target of Curiosity’s study. Four areas were selected, drilled into and samples removed. They were then analyzed by the onboard Sample and Analysis at Mars (SAM) instrument. The gas chromatograph heats up the rocks to 900 degrees Fahrenheit, vaporizing the rock and separating the gases by components. The laser spectrometer measures the amount of each isotope of carbon, hydrogen and oxygen in the gases. This is where it found 3-billion year old carbon and hydrogen.
Detecting and measuring methane is a major function of the laser spectrometer. For the last six years, Curiosity has been recording methane levels in the Gale Crater. Its measurements show seasonal fluctuations in methane levels, peaking in warmer months and going down as it gets cooler. Until now, methane has been unpredictable. Remote measurements of methane have shown fluctuations with no discernable pattern.
These findings are exciting for researchers, uncovering more clues about the history of Mars. Where these molecules came from is still unknown. It is believed that the iconic Gale Crater was created from a large meteor impact that cracked the surface and created a central mountain. Water flowed into the basin, creating a lake and depositing sediment. As the planet dried out the lake disappeared and the sediment was carved out of the crater. Curiosity’s findings lead researchers to believe that water was once a more common feature on the now dusty planet. Water that might have contained microbes.
Curiosity’s long mission on the planet has provided us with incomparable insights into Mars, our neighbor in both proximity and likeness. Everything learned on Mars has far reaching implications to how life began on our exceptional planet and how it might exist on other worlds. With any luck, it will stay active until it is joined by the NASA Mars 2020 rover that will drill for larger samples that could someday be returned to Earth for study in a lab with advanced equipment that can’t fit on a rover. Also, the European Space Agency has the ExoMars rover that is scheduled to arrive in 2021 and it will be able to drill 2-meters down to analyze subsurface material.
Rovers have shown an impressive ability to peel back the mysterious layers of the red planet. With more on the way, we can expect new discoveries for years to come.