Meet SAM, the Sample Analysis at Mars
suite of instruments in the Mars Science Laboratory aboard the Curiosity Rover. Curiosity is on the way to the first investigational site of the mission, a spot with an intriguing mix of geologies called Glenelg
. Nasa seems real excited about what SAM can do and I am too. Check this out:
Previous diaries in this series have highlighted MSL's unique ChemCam and ChemMin instruments. Follow me out into the tall grass to meet SAM and find out how he plans to settle a controversy about life on Mars that dates back to the Viking Lander mission.
In 1976, I was a law student and Gilbert Levin was the scientist whose instrument found strong evidence microbial life on Mars. The "labelled release" experiment on the Viking lander used radioactive tagging to trace bacterial CO2 excretion. The story is covered here.
Dr. Levin designed an experiment which mixed Martian soil with a nutrient containing radioactive carbon.
His hypothesis was that if bacteria were present in the soil, they would metabolise the nutrient and release some of the digested molecules as carbon dioxide.
The result was positive, but NASA rejected the findings because a gas chromatograph instrument on the Viking Lander found no organic molecules. Only recently, it has been confirmed that the Viking's gas chromatograph was not sensitive enough to identify organic molecules as previously believed.
SAM is going to address this in fine detail. This time, according to NASA, SAM combines
a gas chromatograph, a mass spectrometer and a tunable laser spectrometer with combined capabilities to identify a wide range of organic (carbon containing) compounds and determine the ratios of different isotopes of key elements. Isotope ratios are clues to understanding the history of Mars’ atmosphere and water
As I understand the mission profile, the MSL will arrive at Glenelg and conduct its survey in October. Exciting results in planetary exploration may be anticipated just before the election. If the news captivates the public interest, it will most likely sustain our side, the "WE built this" side, of the election meme that is helping Democrats frame the GOP's extreme and dangerous cult of "rampant hyper-individualism
" that makes David Brooks so sad about his beloved Republican Party.
Whether or not news from Mars influences the election, the Mars Science Laboratory is still giving me my biggest space thrill, with every geek bone in my body vibrating, since Neil Armstrong set foot on Tranquility Base.