While the Curiosity rover has already reached its final destination of Mars, it is still making out of this world discoveries. Most recently Curiosity put SAM to the test for the first time. SAM is not a relative of Marvin the Martian, luckily for Bugs Bunny, it is the Sample Analysis at Mars instrument suite. It takes pride of place on Curiosity, making up more than half the science payload. Its primary purpose is to search for carbon compounds which are the building blocks of life. Along with Curiosity, it will assess the planet’s atmosphere and soil chemistry in the Gale Crater.
SAM is capable of analyzing rock, mineral and atmospheric samples. Curiosity’s robotic arm moves the solid samples from the Martian surface into small cups in the Sample Manipulation System (SMS), while atmospheric inlets collect the atmospheric samples for testing. The samples must be heated and vaporized for analysis. This process is performed not by one instrument, but by three.
The Sample Analysis at Mars (SAM) instrument suite without its side panels at NASA Goddard. (Photo Credit: NASA)
SAM’s suite of instruments includes a gas chromatograph, mass spectrometer and tunable laser spectrometer. Compounds and elements are separated by the mass spectrometer, and then they are measured and identified. The gas chromatograph heats up rock and soil samples in order to vaporize the substance and separate the gases for analysis. The laser spectrometer measures isotopes such as oxygen, hydrogen and carbon in atmospheric gases.
SAM is meant to search for organic molecules on Mars; and these organic materials are essential for life – as far as we understand it. While they can exist without producing life, life cannot exist without them. SAM will measure the concentration of organic molecules on the Martian planet with greater accuracy then any instruments before it. So it should follow that many amazing discoveries will be made by Curiosity and the SAM instrument. The absence or presence of organic material will completely change how we view our neighboring planet. If SAM does not find any organic molecules in its ongoing mission, this does not mean that they do not exist, these materials could very well be deeper in the planet.
Click the image above to check out a MSL/NASA video describing SAM and how it analyzes the atmosphere on Mars. (Video Credit: MSL/NASA)
If organic molecules are found by SAM, it would open up whole new avenues of discovery and science while increasing our understanding of Mars. It would also lead to more questions: What are the isotope ratios? Where is it present? What kind of organic molecules? How abundant are they? And where else are they located? These are only a few of the obvious questions that would spur more exploration of the Martian planet and enhance our understanding of the Universe.