The rocky surface of Mars has turned up some rather interestingly-shaped objects in the past. First there was the Martian rat, followed shortly thereafter by the Martian donut; and very recently, the Martian thighbone. And in this latest case, the Curiosity rover has spotted what appears to be a perfectly-round ball. Even more interesting is the fact that this sphere may be yet another indication of Mars’ watery past.
The rock ball was photographed on Sept. 11 – on Sol 746 of the rover’s mission on Mars – while Curiosity was exploring the Gale Crater. One of Curiosity’s cameras captured several images of the centimeter-wide ball as part of the stream of photographs was taking. The scientists working at the Mars Science Laboratory based at NASA’s Jet Propulsion Laboratory (JPL), immediately began to examine it for indications of what it could be.
As Ian O’Neill of Discovery News, who spoke with NASA after the discovery, wrote:
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”… and they were created during sedimentary rock formation when Mars was abundant in liquid water many millions of years ago.
Curiosity has already found evidence of water at a dig site in Yellowknife Bay, which took place shortly after it landed in the Gale Crater two years ago. In addition, this is not the first time a Mars rover has found rocky spheres while examining the surface. In 2004, NASA’s Opportunity rover photographed a group of tiny balls made of a ferrous mineral called hematite. Opportunity photographed still more spheres, of a different composition, eight years later.
The spheres likely formed through a process called “concretion”, where minerals precipitate within sedimentary rock, often into oval or spherical shapes. When the rock erodes due to wind or water, it leaves the balls of minerals behind and exposed. If in fact concretion caused the Mars spheres, then they would be evidence there was once water on the planet. However, some scientists believe the rock balls might be leftover from meteorites that broke up in the Martian atmosphere.
Curiosity is now at the base of Mount Sharp (Aeolis Mons) – The 5.6 km-high (3.5 mile) mountain in the center of Gale Crater – scientists are excited to commence the rover’s main science goal. This will consists of more drilling into layered rock and examining the powder so scientist 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.
Mission managers will need to be careful as the rover has battered wheels from rougher terrain than expected. Because of this, the rover will slowly climb the slope of Mount Sharp driving backwards, so as to minimize the chance of any further damage. The Mars Reconnaissance Orbiter (MRO) will also be on hand to help, photographing the route from above to find the smoothest routes.
Despite the wear and tear that the little rover has experienced in its two years on the Martian surface, it has discovered some amazing things and NASA scientists anticipate that it will accomplish much more in the course of its operational history. And as it carried on with its mission to decode the secrets of Mars, we can expect it will find lots more interesting rocks – spherical, rat-shaped, ringed, femur-like, or otherwise.
As the exploration of Mars goes on, the small army of robotic rovers, satellites and orbiters continue to provide us with information, photographs and discoveries that remind us of how great a mystery the Red Planet truly is. For instance, in the past month, two major stories have been announced concerning the nature of Martian soil, its ancient history, and some of the more exciting moments in it’s exploration.
For example, Curiosity made news as its high resolution camera caught an image of sparks being generated as it zapped a Martian rock. In it’s lifetime, the rover has used its million watt Chemistry and Camera (ChemCam) laser to zap over 600 rock or soil targets as part of its mission. However, this was the first time that the rover team was able to get the arm-mounted Mars Hand Lens Imager (MAHLI) to capture the action as it occurred.
The ChemCam laser is used to determine the composition of Martian rocks and soils at a distance of up to 8 meters (25 feet). By hitting targets with several high-energy pulses, it is able to yield preliminary data for the scientists and engineers back at Earth to help them decide if a target warrants a closer investigation and, in rare cases, sampling and drilling activities.
ChemCam works through a process called laser-induced breakdown spectroscopy. The laser hits a target with pulses to generate sparks, whose spectra provide information about which chemical elements are in the target. Successive laser shots are fired in sequence to gradually blast away thin layers of material. Each shot exposes a slightly deeper layer for examination by the ChemCam spectrometer.
As Curiosity fired deeper into the target rock – named “Nova” – it showed an increasing concentration of aluminum as the sequential laser blasts penetrated through the uninteresting dust on the rock’s surface. Silicon and sodium were also detected. As Sylvestre Maurice, ChemCam’s Deputy Principal Investigator at the Research Institute in Astrophysics and Planetology, said in a statement:
This is so exciting! The ChemCam laser has fired more than 150,000 times on Mars, but this is the first time we see the plasma plume that is created… Each time the laser hits a target, the plasma light is caught and analyzed by ChemCam’s spectrometers. What the new images add is confirmation that the size and shape of the spark are what we anticipated under Martian conditions.
During it’s first year on Mars, Curiosity has already accomplished its primary objective of discovering a habitable zone on Mars that contains the minerals necessary to support microbial life billions of years ago when Mars was wetter and warmer. Currently, the rover is driving swiftly to the base of Mount Sharp at the center of Gale Crater, where it hopes to find more.
In that same vein, according to new geological information obtained by Curiosty’s images and soil examinations, samples that were pulled out of a crater that is estimated to be some 3.7 billion years old contain more evidence that Mars was once much warmer and wetter. These findings were announced in a recent paper published in the online edition of Geology by University of Oregon geologist Gregory Retallack.
Unlike Earth, the Martian landscape is littered with loose rocks from impacts or layered by catastrophic floods. However, recent images from Curiosity from the Gale Crater reveal Earth-like soil profiles with cracked surfaces lined with sulfate, ellipsoidal hollows and concentrations of sulfate comparable with soils in Antarctica’s McMurdo Dry Valleys and Chile’s Atacama Desert.
Retallack, the paper’s lone author, studied mineral and chemical data published by researchers closely tied with the Curiosity mission. As a professor of geological sciences and co-director of paleontology research at the UO Museum of Natural and Cultural History, he internationally known as an expert on the recognition of paleosols – ancient fossilized soils contained in rocks.
As he explains in the paper:
The pictures were the first clue, but then all the data really nailed it. The key to this discovery has been the superb chemical and mineral analytical capability of the Curiosity Rover, which is an order of magnitude improvement over earlier generations of rovers. The new data show clear chemical weathering trends, and clay accumulation at the expense of the mineral olivine, as expected in soils on Earth. Phosphorus depletion within the profiles is especially tantalizing, because it attributed to microbial activity on Earth.
The ancient soils do not prove that Mars once contained life, but they do add to growing evidence that an early, wetter and warmer Mars was more habitable than the planet has been in the past 3 billion years. Surface cracks in the deeply buried soils suggest typical soil clods. Vesicular hollows, or rounded holes, and sulfate concentrations, he said, are both features of desert soils on Earth.
Since Curiosity is currently on its way to Mount Sharp, future missions will be needed to fully explore these features. But as Retallack explained, the parallels with Earth are quite exciting:
None of these features is seen in younger surface soils of Mars. The exploration of Mars, like that of other planetary bodies, commonly turns up unexpected discoveries, but it is equally unexpected to discover such familiar ground.
The newly discovered soils indicate that more benign and habitable soil condition existed on Mars than previously expected. What’s more, their dating to 3.7 billion years ago places them within a transition period when the planet went from an early, benign water cycle to the acidic and arid Mars of today. This is especially important since major changes were taking place on Earth at around the same time.
Roughly 3.5 billion years ago, life on Earth is believed to have emerged and began diversifying. But some scientists have theorized that potential evidence that might indicate that life existed on Earth earlier may have been destroyed by tectonic activity, which did not occur on Mars. Basically, it may offer some credence to the theory that while flourished on Earth, it originated on Mars.
One person who supports this theory is Steven Benner of the Westheimer Institute of Science and Technology in Florida. In the past, he has speculated that life is more likely to have originated on a soil planet like Mars than a water planet like Earth. In an email interview with Science Daily, Benner wrote that Retallack’s paper:
[S]hows not only soils that might be direct products of an early Martian life, but also the wet-dry cycles that many models require for the emergence of life.
So in addition to shedding light on the mysteries of Mars, Curiosity has also been pivotal in addressing some major questions which only increase the mystery of our own existence. Did life as we know it originate on Mars but flourish on Earth? Are there still some remnants of this microbial “Eden” being preserved deep within the soil and rocks? And could life exist there again some day?
All good questions that will no doubt keep robotic rovers, orbiters, landers, and even manned missions busy for many decades to come! In the meantime, check out the video from NASA’s Jet Propulsion Laboratory of Curiosity’s spark-generating laser blast being caught on tape:
In the course of investigating the surface of Mars, NASA has uncovered some rather interesting and curious rock formations. And if once in awhile those rocks should resemble something odd and Earth-like then one should expect the media maelstrom that follows. And the sudden appearance of what people referred to as the “jelly doughnut” rock in January was no exception to this rule.
Much the Martian “rat” discovered last summer, the appearance of the doughnut rock was met with all kinds of speculation. The rock – now dubbed “Pinnacle Island” – first appeared on January 8th in a series of pictures taken by the Opportunity Rover. Measuring only about 4 centimeters (1.5 inches) in diameter with a noticeable white rim and red center, the rock quickly picked up the nickname “jelly doughnut”.
According to pictures taken just four days earlier by Opportunity, during which time it had not moved an inch, that area had been free of debris. In response, wild theories began to emerge, with some thinking it was an indication that rocks were falling from the sky. Others, looking to explain how something so odd in appearance could suddenly have appeared, claimed it was a heretofore undetected Martian surface beings.
Luckily, the ongoing work of mission scientists solved the by determining that the rock was actually created by an “alien invader” – the Opportunity Rover! Apparently, the mysterious rock was created when Opportunity unknowingly drove over a larger rock formation on Solander Point, where she is currently located. It then crushed the rock, sending fragments across the summit.
One piece, the ‘Pinnacle Island’ fragment, unwittingly rolled downhill where Opportunity caught it on camera a few days later. This explanation became apparent when the Opportunity was moved a tiny stretch and took some look-back photographs. Another fragment of the rock that was eerily similar in appearance to the ‘Pinnacle Island’ doughnut appeared, indicating that it had left a trail of such debris in its wake.
Ray Arvidson, Opportunity’s Deputy Principal Investigator, explained in a recent NASA statement:
Once we moved Opportunity a short distance, after inspecting Pinnacle Island, we could see directly uphill an overturned rock that has the same unusual appearance. We drove over it. We can see the track. That’s where Pinnacle Island came from.
To gather some up-close clues before driving away, the rover deployed its robotic arm to investigate ‘Pinnacle Island’ with her microscopic imager and APXS mineral mapping spectrometer. According to Arvidson, the results revealed high levels of the elements manganese and sulfur which suggest that:
[these] water-soluble ingredients were concentrated in the rock by the action of water. This may have happened just beneath the surface relatively recently, or it may have happened deeper below ground longer ago and then, by serendipity, erosion stripped away material above it and made it accessible to our wheels.
The Solander Point mountaintop is riven with outcrops of minerals, including clay minerals, that likely formed in flowing liquid neutral water conducive to life – a potential scientific goldmine. Thus, the presence of such water-soluble minerals in this particular rock indicates quite strongly that the Opportunity brought it with her while rolling through the area.
Meanwhile, on the opposite side of Mars, Opportunity’s younger sister rover Curiosity is trekking towards gigantic Mount Sharp and just crested over the Dingo Gap sand dune. She celebrated 500 days (Sols) on Mars on New Years Day, 2014. And a pair of new orbiters are streaking to the Red Planet to fortify Earth’s invasion fleet- NASA’s MAVEN and India’s MOM.
So expect more surprises from the Red Planet soon enough, which will include more information on surface conditions and the history of Mars’ atmosphere and how it disappeared. And maybe, just maybe, one of the rovers will uncover the existence of the long-sought after organic molecules – thus demonstrating unequivocally that life still exists on Mars.
Hey all! It’s a new year, a new day, but hopefully, there’s still some holiday cheer to go around! And in that spirit, I thought I’d share some news which came in over the holidays concerning Curiosity’s mission to Mars. For the rover, Christmas was celebrated at a location dubbed “Grandmas House”. Well, technically it spent it at Sol 130, a designated point in an area known as “Yellowknife Bay”. This area is a small depression located in the geographic region known as Glenelg, some 400 meters from “Bradbury Landing” where it first put down.
It is in Yellowknife Bay that Curiosity has been engaged in searching for its first target site to drill for a rock sample. The purpose of this to test out the rover’s high powered hammering drill, a test which has been put off because the Mars Science Team feared that the rock samples at other locations were not optimal. But the Glenelg area – which lies at the junction of three different types of geologic terrain – features a different type of geologic terrain compared to what Curiosity has driven on previously.
While there, Curiosity snapped a series of panoramic pictures of the area, which NASA compiled into the photos seen here and at the top. The rover also used its the APXS X-ray mineral spectrometer, ChemCam laser and MAHLI hand lens imager to gather initial science characterization data on the region and its rocky outcroppings. As you can plainly see, Yellowknife Bay was aptly named, being quite similar in appearance to its namesake here on Earth.
Hard to say what Curiosity will find once its begins drilling, but NASA is sure to be raving about it, either way. Everyone knows those Mars Science Laboratory people can’t keep anything a secret, even when they’re not sure they’ve got anything. Yes, MSL, that was a veiled reference to that “Earthshaking news” story you got us all excited about. And to answer you’re next question, no, I haven’t gotten over it yet. Can’t you tell?
Stay tuned for more news from the Red Planet! And while you’re at it, check out the video below where MSL team member Colette Lohr, the Tactical Uplink Lead, provides the latest video update on the Curiosity rover.
The rocky surface of Mars has turned up some rather interestingly-shaped objects in the past. First there was the Martian rat, followed shortly thereafter by the Martian donut; and very recently, the Martian thighbone. And in this latest case, the Curiosity rover has spotted what appears to be a perfectly-round ball. Even more interesting is the fact that this sphere may be yet another indication of Mars’ watery past.
As Ian O’Neill of Discovery News, who spoke with NASA after the discovery, wrote:
The spheres likely formed through a process called “concretion”, where minerals precipitate within sedimentary rock, often into oval or spherical shapes. When the rock erodes due to wind or water, it leaves the balls of minerals behind and exposed. If in fact concretion caused the Mars spheres, then they would be evidence there was once water on the planet. However, some scientists believe the rock balls might be leftover from meteorites that broke up in the Martian atmosphere.
Mission managers will need to be careful as the rover has battered wheels from rougher terrain than expected. Because of this, the rover will slowly climb the slope of Mount Sharp driving backwards, so as to minimize the chance of any further damage. The Mars Reconnaissance Orbiter (MRO) will also be on hand to help, photographing the route from above to find the smoothest routes.
Stories by Williams 