The 'ball' (right of center) can be seen in this sol 746 observation by Mars rover Curiosity's Mastcam. According to NASA scientists it is likely an example of a Martian concretion.
NASA/JPL-Caltech (edit by Jason Major/LightsInTheDark.com)
NASA's rover Curiosity has begun drilling operations for the third time on Mars. Currently located at a geologically interesting location nicknamed "The Kimberley," the one-ton rover also took the opportunity to photograph itself and the surrounding landscape in some stunning Martian "selfies." In this scene, Curiosity appears to be leaning its "head" -- a suite of instruments including the Chemcam (the laser "eye") and Mastcam cameras -- to the side, capturing the 5 kilometer-high Aeolis Mons (a.k.a. "Mount Sharp") on the horizon. The self portrait has been stitched togetherby Discovery News' Jason Major
from a series of raw photographs (taken on sol 613, April 28, of the mission) by Curiosity's robotic arm-mounted Mars Hand Lens Imager (MAHLI) instrument.
NASA/JPL-Caltech (edit by Doug Ellison/JPL)
In this scene, Curiosity appears to be concentrating hard on a rock of interest -- dubbed "Windjana" by mission scientists after a gorge in Western Australia -- that it has cleaned with its robotic arm-mounted Dust Abrasion Tool. A grey circular patch can be seen on the otherwise rusty rock's surface where the tool has scrubbed away any surface dust ready for analysis and drilling. This beautiful selfie was createdby JPL's Doug Ellison
, after assembling a collection of photos from the rover's Mars Hand Lens Imager (MAHLI) on sol 613 (April 28) of the mission. Curiosity's selfies not only produce some breathtaking scenes, they are also used by mission engineers to keep tabs on the condition of the rover the more time it is exposed to the harsh Martian environment.
Curiosity used its Mastcam to photograph this closeup of its Rock Abrasion Tool. The instrument spins the wire-bristle brush over rock surfaces to remove layers of dust that has accumulated.
After brushing, a grey circle of rock beneath the ruddy Mars dust is exposed for further analysis. In this photo by Curiosity's Mars Hand Lens Imager (MAHLI), the texture of Mars dust is obvious and fine cracks or seams in "Windjana" can be seen. "In the brushed spot, we can see that the rock is fine-grained, its true color is much grayer than the surface dust, and some portions of the rock are harder than others, creating the interesting bumpy textures,"said Melissa Rice
, Curiosity science team member, of the California Institute of Technology, Pasadena. "All of these traits reinforce our interest in drilling here in order understand the chemistry of the fluids that bound these grains together to form the rock."
On April 29, Curiosity used its drill to bore a 2 centimeter hole into Windjana. This is only the third rock Curiosity has drilled into since landing on the red planet on Aug. 5, 2012. The grey color obviously extends deeper into the rock than just on its surface, and the powder created can provide a pristine rock sample for further analysis, helping mission scientists understand how the rock formed and under what environmental conditions.
The first two drilled rocks were located in Yellowknife Bay, approximately 4 kilometers from The Kimberley. Those rocks were determined to be mudstone slabs formed through water action and sediment, providing compelling evidence that the interior of Gale Crater used to play host to a lakebed and may have provided a habitable environment for ancient microbial life. This new drilling operation will provide more clues as to how rock formed in the region, revealing more tantalizing clues as to the past habitability of the red planet.
If there’s one thing to be said for Curiosity’s mission on Mars so far, it certainly hasn’t been boring. Although the six-wheeled rover has taken thousands of photographs of Martian rocks, the rich diversity of Mars’ landscape has provided many beautiful examples of planetary geology and some geology that is downright weird.
Take this recent photographic example from the Mars Science Laboratory’s Mastcam camera that was uploaded to the mission’s photo archive on sol 746 (Sept. 11). While compiling a mosaic of images of the surrounding landscape, Curiosity captured a rather un-Mars-like shape atop a rocky outcrop.
There’s a perfect-looking sphere sitting proudly on a flat rock surface. It’s dusty, but under that dust it appears a little darker than the surrounding rock.
At first glance it looks like an old cannonball or possibly a dirty golf ball. But knowing that Mars is somewhat lacking in the 16th Century battleship and golf cart departments, there was likely another answer. Of course it’s nothing man (or alien)-made, despite what your brain might be telling you. It’s another fascinating rock. Yep, it’s a spherical Mars rock.
According to MSL scientists based at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., the ball isn’t as big as it looks — it’s approximately one centimeter wide. Their explanation is that it is most likely something known as a “concretion.” Other examples of concretions have been found on the Martian surface before — take, for example, the tiny haematite concretions, or “blueberries”, observed by Mars rover Opportunity in 2004 — and they were created during sedimentary rock formation when Mars was abundant in liquid water many millions of years ago.
By now we all know that Mars used to be a lot wetter than it is now. Curiosity quickly worked out that it was exploring an ancient lakebed shortly after it landed inside Gale Crater in August 2012. That ancient lakebed is characterized by obvious layering of sedimentary rock. On Earth, sedimentary rock is formed through the interaction of liquid water transporting and depositing material — the same process also occurred on Mars.
Within the newly forming sedimentary rock, pores are inevitably created and minerals seep into those pores, gradually building up an erosion-resistant mass. Over time, as the soft sedimentary rock is eroded away, the concretion remains behind. And this little sphere is one such example — the ball has either emerged from the underlying sedimentary rock that has eroded away or, perhaps, it rolled from somewhere else over time.
Now that Curiosity has reached the base of Aeolis Mons (also known as Mount Sharp), the 3.5 mile-high mountain in the center of Gale Crater, scientists are excited for the rover to begin its next round of drilling operations into the layered rock. Powdered rock samples will then be analyzed so we can gain an idea about how habitable the Red Planet was throughout its ancient history and whether or not it may have been able to support microbial life.
The long two-year journey from its landing site to Mount Sharp hasn’t come without its problems, however. An unanticipated amount of wear and tear by the craggy Mars surface has taken its toll on Curiosity’s wheels, causing dents, punctures and rips in the thin aluminum. This has prompted rover drivers to drive the rover backwards to limit the damage and to get help from NASA’s Mars Reconnaissance Orbiter to image the surrounding landscape, finding the smoothest routes.
But so far, so good, Curiosity is at Mount Sharp to continue its scientific investigation into Mars’ habitable history. So we can expect many more examples of interesting rocks to come, spherical and otherwise.