It’s laborious to imagine that MSL Curiosity has been on Mars for nearly seven years. But it surely has, and through that point, the rover has explored Gale Crater and Mt. Sharp, the central peak contained in the crater. And whereas it has used its drill a number of instances to take rock samples, that is the primary pattern it’s gathered from the so-called ‘clay unit.’
The over-arching objective of the Mars Science Laboratory Curiosity mission is to reply this query: Did Mars ever have the fitting situations for microbes to stay? That query can solely be answered by sampling the soil, air, and rock. Clays are key to the query driving the Curiosity mission as a result of clays type in water, a key requirement for all times.
“Curiosity has been on the street for practically seven years,” stated Curiosity Undertaking Supervisor Jim Erickson of NASA’s Jet Propulsion Laboratory in Pasadena, California. “Lastly drilling on the clay-bearing unit is a significant milestone in our journey up Mount Sharp,” he stated in a press launch.
This pair of pictures reveals the earlier than and after views of the rock it drilled into, referred to as “Aberlady.” When the drill retracted, the rock shifted. Picture Credit score:
The clay-rich rock it drilled into known as “Aberlady.” Curiosity drilled into Aberlady on April sixth, and by April 10th the pattern was delivered to the rover’s on-board mineralogy lab. That lab known as CheMin (Chemistry & Mineralogy X-Ray Diffraction) and it’s mainly an X-Ray Spectrometer.
So far as rocks go, Aberlady was a simple goal for Curiosity’s drill. The rock was a lot softer than a few of its different targets. The drill is a percussive drill, or what carpenters name a hammer drill. It combines a round drilling movement with a hammering movement to drive itself into powerful rock. However on this case, the percussive operate wasn’t wanted.
Now that the pattern has been delivered to CheMin, will probably be analyzed for the presence of clay minerals. Relating to the general image of historic Mars, and its habitability for all times, clay is basically vital.
A Bit About Clay
Again when the Curiosity mission was being deliberate, clay was a central consideration. Clay is definitely a phrase for a number of minerals that share vital traits. There are several types of clay minerals, however all of them type within the presence of water. If Curiosity might discover totally different clay minerals, the pondering went, then we might study one thing about how the traditional water on Mars fashioned these clays and formed the bedrock. By extension, we’d study Mars’ habitability.
The Mars Reconnaissance Orbiter (MRO) performed a job in Curiosity’s mission planning. It recognized a robust “clay sign” from Gale Crater. We all know that Mt. Sharp has totally different layers with totally different minerals. The underside accommodates clay minerals, above which can be layers containing sulfur, and above which can be oxygen-bearing minerals. So, Curiosity was despatched there to observe the clay and look at the layers extra intently, and to search out some clues to Mars’ historic habitability. It seems that water has carved channels into Mt. Sharp and uncovered the layers, making it an much more attractive and enticing vacation spot.
An MRO picture of Gale Crater and Mt. Sharp. The black circle is MSL Curiosity’s touchdown ellipse. Picture Credit score: NASA/JPL-Caltech/MSSS.
Quick ahead to the current, and Curiosity is down on the Martian floor, investigating the clay sign that MRO sensed. All alongside its journey, Curiosity has been sampling clay minerals in rocks, and can accomplish that a number of extra instances this yr. In a press launch, NASA stated that “Pinpointing the supply of that sign
In an electronic mail change with NASA, Curiosity Undertaking Scientist Ashwin Vasavada defined in additional element: “The objective isn’t to chase down the strongest sign by drilling totally different rocks. We’re fairly , nevertheless, to grasp if the clay sign is coming from the native bedrock, versus sand or free rocks. If we drill the bedrock and discover it to be enriched in clay minerals, that’s vital for 2 causes.”
“First, we’ll study one thing concerning the position of historic water in forming or altering the bedrock,” stated Vasavada. “But in addition, we are able to place bedrock inside the general sequence of layered rocks that make up Mount Sharp, in contrast to free sand or boulders. So pinpointing the clay sign inside bedrock tells us concerning the position of water at a selected place and time within the historical past of Mount Sharp.”
Mt. Sharp, or Aeolis Mons, is Curiosity’s major vacation spot. The rover reached Aeolis Mons in September 2014. It was chosen as a result of it seems to be a mountain made up of sedimentary layers. And sediment kinds in water.
Layers on the base of Mt. Sharp. These seen layers in Gale Crater present the chapters of the geological historical past of Mars on this picture from NASA’s Curiosity rover. The picture reveals the bottom of Mount Sharp, the rover’s eventual science vacation spot, and was taken with Curiosity’s Mast Digicam on Aug. 23, 2012. Credit score: NASA/JPL-Caltech/MSSS.
So, as Undertaking Scientist Ashwin Vasavada identified, inspecting these sediment layers and which clay minerals are current in them can inform us quite a bit concerning the geologic historical past of Mars, and whether or not it may need been liveable.
In Gale Crater and on Mt. Sharp, Curiosity has encountered a panorama filled with selection. The panorama accommodates each historic formations like Mt. Sharp itself, and in addition a lot newer formations just like the sand dunes within the crater. There are pebbles all over the place, which can have eroded from bedrock. There’s additionally the characteristic referred to as Knockfarell Hill, named after an iron-age hillfort within the Scottish Highlands. By learning all these options, scientists can begin to paint an image of the timeline of Martian water.
This panorama picture reveals a number of the selection within the Mt. Sharp space. At middle left is Knockfarill Hill. (Click on to enlarge.) Picture Credit score: NASA/JPL-Caltech/MSSS
“Every layer of this mountain is a puzzle piece,” stated Curiosity Undertaking Scientist Ashwin Vasavada of JPL. “They every maintain clues to a unique period in Martian historical past. We’re excited to see what this primary pattern tells us concerning the historic atmosphere, particularly about water.”