NASA Mars Curiosity Rover: Potential signs of ancient life in Mars rover photos

A rock bed at the Gillespie Lake outcrop on Mars displays potential signs of ancient microbial sedimentary structures. 

Credit: NASA

A careful study of images taken by the NASA rover Curiosity has revealed intriguing similarities between ancient sedimentary rocks on Mars and structures shaped by microbes on Earth.

The findings suggest, but do not prove, that life may have existed earlier on the Red Planet.

The photos were taken as Curiosity drove through the Gillespie Lake outcrop in Yellowknife Bay, a dry lakebed that underwent seasonal flooding billions of years ago.

Mars and Earth shared a similar early history. The Red Planet was a much warmer and wetter world back then.

On Earth, carpet-like colonies of microbes trap and rearrange sediments in shallow bodies of water such as lakes and costal areas, forming distinctive features that fossilize over time.

These structures, known as microbially-induced sedimentary structures (or MISS), are found in shallow water settings all over the world and in ancient rocks spanning Earth's history.

Nora Noffke, a geobiologist at Old Dominion University in Virginia, has spent the past 20 years studying these microbial structures.

Last year, she reported the discovery of MISS that are 3.48 billion years old in the Western Australia's Dresser Formation, making them potentially the oldest signs of life on Earth.

In a paper published online last month in the journal Astrobiology (the print version comes out this week), Noffke details the striking morphological similarities between Martian sedimentary structures in the Gillespie Lake outcrop (which is at most 3.7 billion years old) and microbial structures on Earth.

The distinctive shapes include erosional remnants, pockets, domes, roll-ups, pits, chips and cracks, which on Earth can extend from a few centimeters to many kilometers.

Although Noffke makes a tantalizing case for possible signs of ancient life on Mars, her report is not a definitive proof that these structures were shaped by biology.

Getting such confirmation would involve returning rock samples to Earth and conducting additional microscopic analyses, a mission that isn't scheduled anytime in the near future.

"All I can say is, here's my hypothesis and here's all the evidence that I have," Noffke says, "although I do think that this evidence is a lot."

"The fact that she pointed out these structures is a great contribution to the field," says Penelope Boston, a geomicrobiologist at the New Mexico Institute of Mining and Technology.

"Along with the recent reports of methane and organics on Mars, her findings add an intriguing piece to the puzzle of a possible history for life on our neighboring planet."

A Careful Analysis
"I've seen many papers that say 'Look, here's a pile of dirt on Mars, and here's a pile of dirt on Earth,'" says Chris McKay, a planetary scientist at NASA's Ames Research Center and an associate editor of the journal Astrobiology. "And because they look the same, the same mechanism must have made each pile on the two planets.'"

McKay adds: "That's an easy argument to make, and it's typically not very convincing. However, Noffke's paper is the most carefully done analysis of the sort that I've seen, which is why it's the first of its kind published in Astrobiology."

Overlay of sketch on photograph from above to assist in the identification of the structures on the rock bed surface. 

Image credit: Noffke (2105). Credit: ASTROBIOLOGY, published by Mary Ann Liebert, Inc.

The images on which Noffke drew are publicly available on the Mars Science Laboratory page on NASA's website.

"In one image, I saw something that looked very familiar," Noffke recalls. "So I took a closer look, meaning I spent several weeks investigating certain images centimeter by centimeter, drawing sketches, and comparing them to data from terrestrial structures, and I've worked on these for 20 years, so I knew what to look for."

Noffke compared the rover pictures to images taken at several sites on Earth, including modern sediment surfaces in Mellum Island, Germany; Portsmouth Island, USA; and Carbla Point, Western Australia; as well as older fossils of microbial mats in Bahar Alouane, Tunisia; the Pongola Supergroup in Africa; and the Dresser Formation in Western Australia.

The photos showed striking morphological similarities between the terrestrial and Martian sedimentary structures.

The distribution patterns of the microbial structures on Earth vary depending on where they are found. Different types of structures are found together in different types of environments.

For instance, microbial mats that grow in rivers will create a different set of associations than those that grow in seasonally flooded environments.

The patterns found in the Gillespie Lake outcrop are consistent with the microbial structures found in similar environments on Earth.

What's more, the terrestrial structures change in a specific way over time. As the microbial mats form, grow, dry up, crack and re-grow, specific structures become associated with them.

Here again, Noffke found that the distribution pattern in Martian rocks correspond with microbial structures on Earth that have changed over time. Taken together, these clues strengthen her argument beyond simply pointing out the similarities in shape.

In her paper, she also describes alternative processes through which these could have formed. For instance, the chips, pits and cracks could be the product of erosion by salt, water, or wind.

"But if the Martian structures aren't of biological origin," Noffke says, "then the similarities in morphology, but also in distribution patterns with regards to MISS on Earth would be an extraordinary coincidence."

Potential MISS erosional remnant on Mars (top); edge of a microbial mat–overgrown erosional remnant on Portsmouth Island, USA (middle); erosional remnant of a modern MISS on Mellum Island, Germany (bottom). 

Credit: Mars: NASA; Earth: Nora Noffke

"At this point, all I'd like to do is point out these similarities," she adds. "Further evidence must be provided to verify this hypothesis."

More information: The paper is available online: online.liebertpub.com/doi/pdf/… 0.1089/ast.2014.1218

NASA Mars Curiosity Rover: Two Years and Counting on Red Planet

This image from the Navigation Camera on NASA's Curiosity Mars rover shows wheel tracks printed by the rover as it drove on the sandy floor of a lowland called "Hidden Valley" on the route toward Mount Sharp.  

Image courtesy NASA/JPL-Caltech.

NASA's most advanced roving laboratory on Mars celebrates its second anniversary since landing inside the Red Planet's Gale Crater on Aug. 5, 2012, PDT (Aug. 6, 2012, EDT).

During its first year of operations, the Curiosity rover fulfilled its major science goal of determining whether Mars ever offered environmental conditions favorable for microbial life.

Clay-bearing sedimentary rocks on the crater floor in an area called Yellowknife Bay yielded evidence of a lakebed environment billions of years ago that offered fresh water, all of the key elemental ingredients for life, and a chemical source of energy for microbes, if any existed there.

"Before landing, we expected that we would need to drive much farther before answering that habitability question," said Curiosity Project Scientist John Grotzinger of the California Institute of Technology, Pasadena.

"We were able to take advantage of landing very close to an ancient streambed and lake. Now we want to learn more about how environmental conditions on Mars evolved, and we know where to go to do that."

During its second year, Curiosity has been driving toward long-term science destinations on lower slopes of Mount Sharp.

Those destinations are in an area beginning about 2 miles (3 kilometers) southwest of the rover's current location, but an appetizer outcrop of a base layer of the mountain lies much closer -- less than one-third of a mile (500 meters) from Curiosity. The rover team is calling the outcrop "Pahrump Hills."

For about half of July, the rover team at NASA's Jet Propulsion Laboratory in Pasadena, California, drove Curiosity across an area of hazardous sharp rocks on Mars called "Zabriskie Plateau."

Damage to Curiosity's aluminum wheels from driving across similar terrain last year prompted a change in route, with the plan of skirting such rock-studded terrain wherever feasible.

The one-eighth mile (200 meters) across Zabriskie Plateau was one of the longest stretches without a suitable detour on the redesigned route toward the long-term science destination.

NASA Mars Curiosity spots a heavy metal meteorite - Lebanon

2-meter wide iron meteorite dubbed “Lebanon,” as imaged by Curiosity’s ChemCam and Mastcam on May 25, 2014. 

Credit: NASA /JPL-Caltech /LANL /CNES /IRAP /LPGNantes /CNRS /IAS /MSSS

Talk about heavy metal! This shiny, lumpy rock spotted by NASA's Curiosity rover is likely made mostly of iron, and came from outer space!

It's an iron meteorite, similar to ones found in years past by Curiosity's forerunners Spirit and Opportunity, but is considerably larger than any of the ones the MER rovers came across… in fact, at 2 meters (6.5 feet) wide this may very well be the biggest meteorite ever discovered on Mars!

The picture above was made by combining high-resolution circular images (outlined in white) acquired with the Remote Micro-Imager (RMI) of Curiosity's ChemCam instrument with colour and context from the rover's Mastcam.

The images were taken on mission Sol 640 (May 25, 2014) and have been adjusted to simulate more Earth-like illumination.

Dubbed "Lebanon," the large meteorite has a smaller fragment lying alongside it, named "Lebanon B."

While iron meteorites are fairly common on Earth, on Mars they are by far the most common types of meteorites that have been discovered, if just for the sheer fact that they are highly resistant to erosion.

Original raw Mastcam (right) image of Lebanon and Lebanon B from Sol 640. 

Credit: NASA /JPL-Caltech /MSSS

Mars Curiosity Rover: Travels outside landing ellipse

Nasa Curiosity Rover treks across Martian dunes and drives outside landing ellipse here, in this photo mosaic view captured on Sol 672, June 27, 2014. 

Distant eroded rim of Gale Crater seen in background. Navcam camera raw images stitched and colorized. 

Credit: NASA /JPL-Caltech /Marco Di Lorenzo /Ken Kremer

NASA's intrepid robot Curiosity is roving rapidly across the sandy ripples of the Red Planet in her quest to reach mysterious Mount Sharp and just drove outside her landing ellipse!

The six wheeled rover marked a major milestone on Sol 672, June 27, 2014, by driving beyond her targeted landing ellipse for the first time since touchdown nearly two years ago on August 5, 2012.

"On yestersol's drive [June 27], I left my landing ellipse, the 20×25 km area I targeted for landing," Curiosity tweeted across interplanetary space.

See our new Sol 672 photo mosaic above showing Curiosity's glorious view marking this major achievement just days ago.

Since switching paths to smoother, sandier terrain with less sharp edged rocks, Curiosity continues rolling across the floor of her Gale Crater landing site.

"After traversing 82 meters the rover stopped because it determined that it was slipping too much," wrote mission scientist Ken Herkenhoff in an update.

"Coincidentally, the rover stopped right on the landing ellipse, a major mission milestone!"

"The vehicle was designed to be able to traverse far enough to drive out of the region defined by the uncertainty in the landing location, and has now achieved that laudable goal."

Curiosity treks to Mount Sharp in this photo mosaic view captured on Sol 669, June 24, 2014. 

Navcam camera raw images stitched and coloured. 

Credit: NASA /JPL-Caltech /Marco Di Lorenzo /Ken Kremer

The SUV sized rover automatically stopped when it encountered soft sand and sensed that it wasn't making enough progress. It's been programmed with this built in safety check to avoid being trapped in a quagmire.

Earlier last week, Curiosity celebrated another milestone anniversary on June 24 (Sol 669), 1 Martian Year on Mars!

A Martian year is equivalent to 687 Earth days, or nearly two Earth years.

Curiosity crosses landing ellipse on Sol 672. 

Credit: NASA/JPL

During Year 1 on Mars, Earth's emissary has already accomplished her primary objective of discovering a habitable zone on the Red Planet that contains the minerals necessary to support microbial life in the ancient past.

So there's no stopping Curiosity on her way to Mount Sharp, which dominates the center of Gale Crater and reaches 3.4 miles (5.5 km) into the Martian sky, taller than Mount Rainier.

Curiosity rover panorama of Mount Sharp captured on June 6, 2014 (Sol 651) during traverse inside Gale Crater. 

Note rover wheel tracks at left. She will eventually ascend the mountain at the ‘Murray Buttes’ at right later this year. 

Assembled from Mastcam colour camera raw images and stitched by Marco Di Lorenzo and Ken Kremer. 

Credit: NASA /JPL /MSSS /Marco Di Lorenzo /Ken Kremer

Driving, Driving, Driving, that's Curiosity's number one priority as she traverses across the surface of Gale Crater towards towering Mount Sharp on an expedition in search of the chemical ingredients of life that could support Martian microbes if they ever existed.

Curiosity still has about another 2.4 miles (3.9 kilometers) to go to reach the entry way at a gap in the dunes at the foothills of Mount Sharp sometime later this year.

To date, Curiosity's odometer totals over 5.1 miles (8.4 kilometers) since landing inside Gale Crater on Mars in August 2012. She has taken over 162,000 images.

NASA Mars Curiosity Rover: MSL, where it's been and where it's going - video

The path the Mars Science Laboratory has taken, started in the plains of the Gale crater and ultimately will makes its way through rough roads on the way to a Mount Sharp climb. 

Curiosity project scientist John Grotzinger explains.

Credit: NASA / JPL-Caltech

NASA Mars Curiosity Rover: 'Murray Ridge' on Mars

This scene shows the "Murray Ridge" portion of the western rim of Endeavour Crater on Mars.

The ridge is the NASA's Mars Exploration Rover Opportunity's work area for the rover's sixth Martian winter.

The ridge rises about 130 feet (40 meters) above the surrounding plain, between "Solander Point" at the north end of the ridge and "Cape Tribulation," beyond Murray Ridge to the south.

This view does not show the entire ridge. The visible ridge line is about 10 meters (33 feet) above the rover's location when the component images were taken.

The scene sweeps from east to south. The planar rocks in the foreground at the base of the hill are part of a layer of rocks laid down around the margins of the crater rim.

At this location, Opportunity is sitting at the contact between the Meridiani Planum sandstone plains and the rocks of the Endeavour Crater rim.

On the upper left, the view is directed about 22 kilometers (14 miles) across the center of Endeavour crater to the eastern rim.

Panoramic camera

The scene combines several images taken by the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity during the 3,446th Martian day, or sol, of the mission's work on Mars (Oct. 3, 2013) and the following three sols.

On Sol 3451 (Oct. 8, 2013), Opportunity began climbing the ridge.

The slope offers outcrops that contain clay minerals detected from orbit and also gives the rover a northward tilt that provides a solar-energy advantage during the Martian southern hemisphere's autumn and winter.

The rover team chose to call this feature Murray Ridge in tribute to Bruce Murray (1931-2013), an influential advocate for planetary exploration who was a member of the science teams for NASA's earliest missions to Mars and later served as director of NASA's Jet Propulsion Laboratory, in Pasadena.

This view is presented in approximately true colour, merging exposures taken through three of the Pancam's colour filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet).

Image Credit: NASA /JPL-Caltech /Cornell/ASU

Perchlorates: Mars Chemical Changes Search for Red Planet Life

The Curiosity Rover took this composite self-portrait in the Rocknest sand patch on Mars. Tests of soil at the site suggest that troublesome chemicals called perchlorates are common on the Red Planet.

Credit: NASA

Astronauts sent to Mars on future space missions will have to contend with the toxic and explosive chemical known as perchlorate that's widespread in Red Planet dirt.

Perchlorates have already proved to be problematic for researchers using robotic rovers to hunt for possible traces of Martian life, a new study has found.

As part of its science mission, NASA's Mars rover Curiosity heats up scoops of Red Planet dirt to test for organic carbon compounds — the building blocks of life on Earth.

But that heat can cause perchlorates in soil samples to set off a chemical reaction that destroys organics, researchers discovered.

Daniel Glavin

"The presence of perchlorates isn't good news for some of the techniques currently being used with Curiosity," study lead author Daniel Glavin, an astrobiologist at NASA’s Goddard Space Flight Center in Greenbelt, Md., said in a statement.

"This may change the way we search for organics in the future on Mars."

Perchlorates, which are salts comprised of chlorine and oxygen, were first detected in Martian polar soil by NASA's Phoenix lander in May 2008.

More recently, Curiosity found perchlorates while trekking around the Rocknest sand dune in November 2012.

Curiosity's Sample Analysis at Mars (SAM) system uses a pyrolysis gas chromatograph mass spectrometer, which is an instrument that breaks soil down into its chemical components and measures the concentration of each type of molecule.

But when perchlorates in these soil samples are heated above 392 degrees Fahrenheit (200 degrees Celsius), they release pure oxygen, the researchers say.

This oxygen then causes organic molecules in the sample to combust into carbon dioxide.


However, Glavin said not all of the organic carbon would be destroyed in this reaction; some might be preserved inside more heat-resistant materials, or the molecules could possibly be detected before the breakdown of perchlorates.

Scientists might be able to account for the organic carbon that has combusted if they assume a certain baseline of perchlorate in Martian dirt, he added.

The recent findings at Rocknest could help scientists establish this baseline.

"It will be absolutely critical as we move on to other samples to compare them to the Rocknest dune to infer the presence or absence of Martian organic material," Glavin said in a statement.

NASA MARS Curiosity Rover: MSL finds no trace of Methane on Mars

Data from NASA's Curiosity rover has revealed the Martian environment lacks methane.

This is a surprise to researchers because previous data reported by U.S. and international scientists indicated positive detections.

The roving laboratory performed extensive tests to search for traces of Martian methane.

Whether the Martian atmosphere contains traces of the gas has been a question of high interest for years because methane could be a potential sign of life, although it also can be produced without biology.

"This important result will help direct our efforts to examine the possibility of life on Mars," said Michael Meyer, NASA's lead scientist for Mars exploration.

Michael Meyer

"It reduces the probability of current methane-producing Martian microbes, but this addresses only one type of microbial metabolism. As we know, there are many types of terrestrial microbes that don't generate methane."

Curiosity analyzed samples of the Martian atmosphere for methane six times from October 2012 through June and detected none.

Given the sensitivity of the instrument used, the Tunable Laser Spectrometer, and not detecting the gas, scientists calculate the amount of methane in the Martian atmosphere today must be no more than 1.3 parts per billion.

That is about one-sixth as much as some earlier estimates. Details of the findings appear in the Thursday edition of Science Express.

Chris Webster

"It would have been exciting to find methane, but we have high confidence in our measurements, and the progress in expanding knowledge is what's really important," said the report's lead author, Chris Webster of NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"We measured repeatedly from Martian spring to late summer, but with no detection of methane."

Mars Curiosity Rover Captures 2 Mars Moons Together - NASA Video

A spectacular new video from NASA's Mars rover Curiosity shows the Red Planet's two tiny moons eclipsing each other in an otherworldly skywatching first.

Curiosity snapped 41 images of the Mars moons in the night sky on Aug. 1, with rover scientists then stitching them together to make the final 30-second video. It is the first time a view of the two Martian satellites — called Phobos and Deimos — eclipsing each other has been captured from the vantage point of the planet's surface, NASA officials said.

The new Curiosity video has plenty of scientific value in addition to its gee-whiz appeal, officials said. For example, researchers are studying the images to refine their knowledge of the orbits of Phobos and Deimos, both of which appear to be captured asteroids.

Mark Lemmon

"The ultimate goal is to improve orbit knowledge enough that we can improve the measurement of the tides Phobos raises on the Martian solid surface, giving knowledge of the Martian interior," Mark Lemmon of Texas A&M University said in a statement.

"We may also get data good enough to detect density variations within Phobos and to determine if Deimos' orbit is systematically changing," added Lemmon, who is a co-investigator for Curiosity's Mastcam instrument, which took the pictures using its telephoto lens.

Phobos' orbit is taking it closer to the surface of Mars very slowly, researchers said, while Deimos may gradually be getting farther and farther away from the planet.

Phobos is just 14 miles (22 kilometers) wide on average, while Deimos is even smaller. But Curiosity was able to spot both of them because they orbit quite close to the Red Planet's surface — 3,700 miles (6,000 km) in Phobos' case and 12,470 miles (20,070 km) for Deimos.

Earth's moon is gigantic compared to Phobos and Deimos, with a diameter of about 2,160 miles (3,475 km). But our planet's natural satellite orbits much farther away — its average distance is 239,000 miles (384,600 km) — so Phobos appears half as big in the sky to Curiosity as Earth's moon does to human skywatchers, NASA officials said.

This illustration provides a comparison for how big the moons of Mars appear to be, as seen from the surface of Mars, in relation to the size that Earth's moon appears to be when seen from the surface of Earth. 

Deimos, at far left, and Phobos, beside it, are shown together as they actually were photographed by the Mast Camera (Mastcam) NASA's Mars rover Curiosity on Aug. 1, 2013.

Credit: NASA/JPL-Caltech/Malin Space Science Systems/Texas A&M Univ.

NASA Mars Curiosity Rover: Billion-Pixel Image Shows Mars in Stunning Detail

This is a reduced version of a mosaic from NASA's Mars rover Curiosity containing 1.3 billion pixels in the full-resolution version. 

It shows Curiosity at the "Rocknest" site, where the rover scooped up samples of windblown dust and sand, and was released on June 19, 2013. 

Viewers can explore this image with pan and zoom controls at http://mars.nasa.gov/bp1/.

CREDIT: NASA/JPL-Caltech/MSSS

A new 1.3-billion-pixel image from NASA’s Mars rover Curiosity allows viewers to zoom in and investigate part of the Red Planet in incredible detail.

The huge mosaic stitches together nearly 900 photos that the Curiosity rover took with some of its 17 cameras during the robot's exploration of Gale Crater on Mars, NASA officials said.

"It gives a sense of place and really shows off the cameras' capabilities," Bob Deen, of the Multi-Mission Image Processing Laboratory at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. "You can see the context and also zoom in to see very fine details."



Deen constructed the mosaic using 871 pictures from Curiosity's Mast Camera instrument and 25 black-and-white frames from the rover's navigation cameras.

The photos were taken between Oct. 5 and Nov. 16, 2012, officials said.

Curiosity landed inside the 96-mile-wide (154 km) Gale Crater on Aug. 5, 2012, kicking off a planned two-year surface mission to assess Mars' past and present potential to host microbial life.

In addition to its 17 cameras, Curiosity also carries 10 different science instruments to aid its quest.

The six-wheeled robot has already checked off its primary goal. Mission scientists announced in March that a spot near Curiosity's landing site called Yellowknife Bay was indeed habitable long ago.