After Curiosity had a bite of Martian turf at the site of Rocknest a few days earlier, soil analysis results have finally come in. According to scientists at NASA, the Martian sand in the rover’s vicinity is very much akin to volcanic soils found on Earth such as those of Hawaii. Though Mars is far from being a resort itself.
The findings follow a slew of premiering successes from Curiosity, as the high-tech lab on wheels recently performed for the first time analysis using the alpha particle X-ray spectrometer at the end of its arm, and shot the ChemCam laser on its mast at spots up to 23 feet away to analyze the rock it vaporizes. The next instrument in lined was its chemistry and mineralogy module, known as CheMin, which bombards soil samples with X-rays to reveal their mineral composition and abundance.
Like I said, Curiosity successfully trialed other instruments on-board in the past few weeks, some of which also offered detailed elemental analysis. But knowing what atoms and molecules make up a sample is far from being enough, since the manner in which they are arranged counts just as much. Take carbon for instance, the most famous allotrope; it can occur as graphite, a very soft material typically used in pencils, or diamond, one of the hardest materials known to man. So you see while the chemical mark-up is the same, the way the carbon atoms are connected with one another makes all the difference in the world.
The instrument, called CheMin, for chemistry and mineralogy, is a marvel of miniaturization. No larger than a shoe box, it fits inside the rover and does the same analytic work as X-ray diffraction instruments the size of refrigerators. After Curiosity uses a scoop at the end of its arm to collect soil, it carefully positions the tablet sized sample in the CheMin instrument. Before analysis can begin, however, the instruments shooks the sample 2000 times per second to filter out larger grains; the remaining crystals are then bombarded with X-rays in order to revelad their precise atomic structure. This was the first time X-rays from Earth have been deployed on an alien planet.
Roughly half the Martian soil, NASA scientists say, appears to be noncrystalline particles, meaning they’re like obsidian, a form of volcanic glass that the CheMin instrument’s x-rays cannot probe. This will be tasked to other instruments.
The Curiosity Rover main objective in its 2-year mission is that of reaching the Gale Crater’s Mt. Sharp, a 3-mile-high mountain in the middle of the crater whose lower layers may hold clues to whether Mars is capable of sustaining life or not.