Category Archives: Mars Rovers

Curious Travels on Pahrump Hills

I must say I’m a bit surprised at the diversity of minerals in the samples between sites.

 
NASA scientists have found a wide diversity of minerals in the initial samples of rocks collected by the Curiosity rover in the lowermost layers of Mount Sharp on Mars, suggesting that conditions changed in the water environments on the planet over time.

Curiosity landed near Mount Sharp in Gale Crater in August 2012. It reached the base of the mountain in 2014. Layers of rocks at the base of Mount Sharp accumulated as sediment within ancient lakes around 3.5 billion years ago. Orbital infrared spectroscopy had shown that the mountain’s lowermost layers have variations in minerals that suggest changes in the area have occurred.

In a paper published recently in Earth and Planetary Science Letters, scientists in the Astromaterials Research and Exploration Science (ARES) Division at NASA’s Johnson Space Center in Houston report on the first four samples collected from the lower layers of Mount Sharp.

“We went to Gale Crater to investigate these lower layers of Mount Sharp that have these minerals that precipitated from water and suggest different environments,” said Elizabeth Rampe, the first author of the study and a NASA exploration mission scientist at Johnson. “These layers were deposited about 3.5 billion years ago, coinciding with a time on Earth when life was beginning to take hold. We think early Mars may have been similar to early Earth, and so these environments might have been habitable.”

The minerals found in the four samples drilled near the base of Mount Sharp suggest several different environments were present in ancient Gale Crater. There is evidence for waters with different pH and variably oxidizing conditions. The minerals also show that there were multiple source regions for the rocks in “Pahrump Hills” and “Marias Pass.”

The paper primarily reports on three samples from the Pahrump Hills region. This is an outcrop at the base of Mount Sharp that contains sedimentary rocks scientists believe formed in the presence of water. The other sample, called “Buckskin,” was reported last year, but those data are incorporated into the paper.

Studying such rock layers can yield information about Mars’ past habitability, and determining minerals found in the layers of sedimentary rock yields much data about the environment in which they formed. Data collected at Mount Sharp with the Chemistry and Mineralogy (CheMin) instrument on Curiosity showed a wide diversity of minerals.

At the base are minerals from a primitive magma source; they are rich in iron and magnesium, similar to basalts in Hawaii. Moving higher in the section, scientists saw more silica-rich minerals. In the “Telegraph Peak” sample, scientists found minerals similar to quartz. In the “Buckskin” sample, scientists found tridymite. Tridymite is found on Earth, for example, in rocks that formed from partial melting of Earth’s crust or in the continental crust — a strange finding because Mars never had plate tectonics.

In the “Confidence Hills” and “Mojave 2” samples, scientists found clay minerals, which generally form in the presence of liquid water with a near-neutral pH, and therefore could be good indicators of past environments that were conducive to life. The other mineral discovered here was jarosite, a salt that forms in acidic solutions. The jarosite finding indicates that there were acidic fluids at some point in time in this region.

There are different iron-oxide minerals in the samples as well. Hematite was found near the base; only magnetite was found at the top. Hematite contains oxidized iron, whereas magnetite contains both oxidized and reduced forms of iron. The type of iron-oxide mineral present may tell scientists about the oxidation potential of the ancient waters.

The authors discuss two hypotheses to explain this mineralogical diversity. The lake waters themselves at the base were oxidizing, so either there was more oxygen in the atmosphere or other factors encouraged oxidation. Another hypothesis — the one put forward in the paper — is that later-stage fluids arose. After the rock sediments were deposited, some acidic, oxidizing groundwater moved into the area, leading to precipitation of the jarosite and hematite. In this scenario, the environmental conditions present in the lake and in later groundwater were quite different, but both offered liquid water and a chemical diversity that could have been exploited by microbial life.

“We have all this evidence that Mars was once really wet but now is dry and cold,” Rampe said. “Today, much of the water is locked up in the poles and in the ground at high latitudes as ice. We think that the rocks Curiosity has studied reveal ancient environmental changes that occurred as Mars started to lose its atmosphere and water was lost to space.”

In the paper, the authors discuss whether this specific area on Mars is a mark of this event happening or just a natural drying of this area. Scientists will search for answers to these questions as the rover moves up the mountain.

Image: NASA/JPL-Caltech/MSSS

NASA also provided a link to the paper (downloadable PDF)

A Scenario for Gale Crater on Mars

So this brings up the question would have the same oxidation processes interfered with life processes at a critical early state or would have it actually assisted them?   Good work by Stony Brook and NASA.

NASA — This diagram presents some of the processes and clues related to a long-ago lake on Mars that became stratified, with the shallow water richer in oxidants than deeper water was.

The sedimentary rocks deposited within a lake in Mars’ Gale Crater more than three billion years ago differ from each other in a pattern that matches what is seen in lakes on Earth. As sediment-bearing water flows into a lake, bedding thickness and particle size progressively decrease as sediment is deposited in deeper and deeper water as seen in examples of thick beds (PIA19074) from shallowest water, thin beds (PIA19075) from deeper water and even thinner beds (PIA19828) from deepest water.

At sites on lower Mount Sharp, inside the crater, measurements of chemical and mineral composition by NASA’s Curiosity Mars rover reveal a clear correspondence between the physical characteristics of sedimentary rock from different parts of the lake and how strongly oxidized the sediments were. Rocks with textures indicating that the sediments were deposited near the edge of a lake have more strongly oxidized composition than rocks with textures indicating sedimentation in deep water. For example, the iron mineral hematite is more oxidized than the iron mineral magnetite.

An explanation for why such chemical stratification occurs in a lake is that the water closer to the surface is more exposed to oxidizing effects of oxygen in the atmosphere and ultraviolet light.

On Earth, a stratified lake with a distinct boundary between oxidant-rich shallows and oxidant-poor depths provides a diversity of environments suited to different types of microbes. If Mars has ever hosted microbial live, the stratified lake at Gale Crater may have similarly provided a range of different habitats for life.

Image: NASA/JPL-Caltech/Stony Brook University

Martian Halos

REMINDER:  There will be a Space X launch at 21:55 UT / 17:55 ET today!  I will have a live feed up.  Nobody does launch video like Space X.

NASA – Pale zones called “halos” border bedrock fractures visible in this 2015 image from NASA’s Curiosity Mars rover which has been darkened (a previously released image can be seen at PIA20268). Measurements overlaid on the image offer a sense of scale for the size of these fractures. The rover team determined that the halos are rich in silica, a clue to the duration of wet environmental conditions long ago. The location is on the lower slope of Mars’ Mount Sharp.

Curiosity’s Navigation Camera (Navcam) acquired the component images of this mosaic on Aug. 23, 2015, during the 1.083rd Martian day, or sol, of the mission. The location is along the rover’s path between “Marias Pass” and “Bridger Basin.” In this region, the rover has found fracture zones to be associated with rock compositions enriched in silica, relative to surrounding bedrock.

Image:  NASA/JPL-Caltech

Opportunity Update

Yes the Mars Exploration Rover Opportunity is STILL doing good science on the Martian surface since arriving at  Mars on 25 January 2004 – that’s over 13 years ago!  Go Oppy!

The image above is a cropped version of the original (find it here at NASA). The tracks are visible in the lower center of the image.

Here’s the NASA caption:

NASA’s Mars Exploration Rover Opportunity worked for 30 months on a raised segment of Endeavour Crater’s rim called “Cape Tribulation” until departing that segment in mid-April 2017, southbound toward a new destination. This view looks back at the southern end of Cape Tribulation from about two football fields’ distance away. The component images were taken by the rover’s Panoramic Camera (Pancam) on April 21, during the 4,707th Martian day, or sol, of Opportunity’s mission on Mars.

Wheel tracks can be traced back to see the rover’s route as it descended and departed Cape Tribulation. For scale, the distance between the two parallel tracks is about 3.3 feet (1 meter). The rover drove from the foot of Cape Tribulation to the head of “Perseverance Valley” in seven drives totaling about one-fifth of a mile (one-third of a kilometer). An annotated map of the area is at PIA21496. (edit: link goes off site use your back button to return)

The elevation difference between the highest point visible in this scene and the rover’s location when the images were taken is about 180 feet (55 meters).

This view looks northward. It merges exposures taken through three of the Pancam’s color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). It is presented in approximately true color.

Image Credit:  NASA/JPL-Caltech/Cornell/Arizona State Univ.

 

Sand Dunes on Mars

It has been a while since I’ve done a Curiosity rover update. Curiosity continues to do great science on Mars, although the wheels are showing more wear and hopefully design modifications are in place for the next rover. Still, Curiosity can get around and with judicious planning it will continue to do so in the future.

The image shows there is wind on Mars and that helps keep Curiosity clean enough to provide power for operations and the wind is strong enough to make ripples in the landscape. One would imagine the texture is very fine because the wind is blowing in a thin atmosphere. The primarily Carbon Dioxide atmosphere (95.6 %) on Mars has a pressure only around 0.6 percent of what we see here on Earth.

NASA – This view from the Mast Camera (Mastcam) on NASA’s Curiosity Mars rover shows two scales of ripples, plus other textures, in an area where the mission examined a linear-shaped dune in the Bagnold dune field on lower Mount Sharp.

The scene is an excerpt from a 360-degree panorama acquired on March 24 and March 25, 2017, (PST) during the 1,647th Martian day, or sol, of Curiosity’s work on Mars, at a location called “Ogunquit Beach.”

Crests of the longer ripples visible in the dark sand of the dune are several feet (a few meters) apart. This medium-scale feature in active sand dunes on Mars was one of Curiosity’s findings at the crescent-shaped dunes that the rover examined in late 2015 and early 2016. Ripples that scale are not seen on Earth’s sand dunes. Overlaid on those ripples are much smaller ripples, with crests about ten times closer together.

Textures of the local bedrock in the foreground — part of the Murray formation that originated as lakebed sediments — and of gravel-covered ground (at right) are also visible. The image has been white-balanced so that the colors of the colors of the rock and sand materials resemble how they would appear under daytime lighting conditions on Earth.

Image: NASA/JPL-Caltech/MSSS

Kick Those Tires

We have been following the wheel wear on the Curiosity rover for a few years now.

NASA of course noticed and have been keeping an eye on the wheels with regular inspections.  New breaks in the tread have been found.

Credits: NASA/JPL-Caltech/MSSS

Here’s the latest status report from NASA:

A routine check of the aluminum wheels on NASA’s Curiosity Mars rover has found two small breaks on the rover’s left middle wheel—the latest sign of wear and tear as the rover continues its journey, now approaching the 10-mile (16 kilometer) mark.

The mission’s first and second breaks in raised treads, called grousers, appeared in a March 19 image check of the wheels, documenting that these breaks occurred after the last check, on Jan. 27.

“All six wheels have more than enough working lifespan remaining to get the vehicle to all destinations planned for the mission,” said Curiosity Project Manager Jim Erickson at NASA’s Jet Propulsion Laboratory, Pasadena, California. “While not unexpected, this damage is the first sign that the left middle wheel is nearing a wheel-wear milestone,”

The monitoring of wheel damage on Curiosity, plus a program of wheel-longevity testing on Earth, was initiated after dents and holes in the wheels were seen to be accumulating faster than anticipated in 2013. Testing showed that at the point when three grousers on a wheel have broken, that wheel has reached about 60 percent of its useful life. Curiosity already has driven well over that fraction of the total distance needed for reaching the key regions of scientific interest on Mars’ Mount Sharp.

Curiosity Project Scientist Ashwin Vasavada, also at JPL, said, “This is an expected part of the life cycle of the wheels and at this point does not change our current science plans or diminish our chances of studying key transitions in mineralogy higher on Mount Sharp.”

Curiosity is currently examining sand dunes partway up a geological unit called the Murray formation. Planned destinations ahead include the hematite-containing “Vera Rubin Ridge,” a clay-containing geological unit above that ridge, and a sulfate-containing unit above the clay unit.

The rover is climbing to sequentially higher and younger layers of lower Mount Sharp to investigate how the region’s ancient climate changed billions of years ago. Clues about environmental conditions are recorded in the rock layers. During its first year on Mars, the mission succeeded at its main goal by finding that the region once offered environmental conditions favorable for microbial life, if Mars has ever hosted life. The conditions in long-lived ancient freshwater Martian lake environments included all of the key chemical elements needed for life as we know it, plus a chemical source of energy that is used by many microbes on Earth.

Through March 20, Curiosity has driven 9.9 miles (16.0 kilometers) since the mission’s August 2012 landing on Mars. Studying the transition to the sulfate unit, the farthest-uphill destination, will require about 3.7 miles (6 kilometers) or less of additional driving. For the past four years, rover drive planners have used enhanced methods of mapping potentially hazardous terrains to reduce the pace of damage from sharp, embedded rocks along the rover’s route.

Each of Curiosity’s six wheels is about 20 inches (50 centimeters) in diameter and 16 inches (40 centimeters) wide, milled out of solid aluminum. The wheels contact ground with a skin that’s about half as thick as a U.S. dime, except at thicker treads. The grousers are 19 zigzag-shaped treads that extend about a quarter inch (three-fourths of a centimeter) outward from the skin of each wheel. The grousers bear much of the rover’s weight and provide most of the traction and ability to traverse over uneven terrain.

JPL, a division of Caltech in Pasadena, California, manages NASA’s Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington, and built the project’s rover, Curiosity. For more information about the mission, visit:

 

 

Martian Mud Cracks?

Yet more evidence of water on Mars. Would we be able to detect any traces of life if it existed after a couple thousand-million years or so?

From NASA:

The network of cracks in this Martian rock slab called “Old Soaker” may have formed from the drying of a mud layer more than 3 billion years ago. The view spans about 4 feet (1.2 meters) left-to-right and combines three images taken by the Mars Hand Lens Imager (MAHLI) camera on the arm of NASA’s Curiosity Mars rover.

Mud cracks would be evidence of a time when dry intervals interrupted wetter periods that supported lakes in the area. Curiosity has found evidence of ancient lakes in older, lower-lying rock layers and also in younger mudstone that is above Old Soaker.

MAHLI was positioned about 3 feet (90 centimeters) above the surface when it took the component images on Dec. 31, 2016, during the 1,566th Martian day, or sol, of Curiosity’s work on Mars. This observation was planned as part of assessing a hypothesis that the target preserves evidence of drying mud. The location is within an exposure of Murray formation mudstone on lower Mount Sharp inside Gale Crater.

The slab bears a network of four- and five-sided polygons about half an inch to 1 inch (1 to 2 centimeters) across, which matches the pattern commonly formed when a thin layer of mud dries. Some edges of the polygons are ridges of material the same color as the surrounding rock. This could result from a three-step process after cracks form due to drying: Wind-blown sediments accumulate in the open cracks. Later, these sediments and the dried mud become rock under the pressure of multiple younger layers that accumulate on top of them. Most recently, after the overlying layers were eroded away by wind, the vein-filling material resists erosion better than the once-muddy material, so the pattern that began as cracks appears as ridges.

Note that some of the cracks contain material much brighter than the surrounding rock. These are mineral veins. Curiosity has found such bright veins of calcium sulfate in many rock layers the rover has investigated. These veins form from circulation of mineral-laden groundwater through underground cracks. Rover-team scientists suggest that a likely scenario for the history of Old Soaker is more than one generation of fracturing: mud cracks first, with sediment accumulating in them, then a later episode of underground fracturing and vein forming.

The target rock’s name comes from the name of an island off the coast of Maine. The names informally assigned by the rover team to features in the area of lower Mount Sharp that includes this slab are from a list of islands, hills and other sites in or near Maine’s Bar Harbor.

Malin Space Science Systems, San Diego, built and operates MAHLI. NASA’s Jet Propulsion Laboratory, a division of the Caltech in Pasadena, California, manages the Mars Science Laboratory Project for the NASA Science Mission Directorate, Washington, and built the project’s Curiosity rover. More information about Curiosity is online at http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/.

Credit: NASA/JPL-Caltech/MSSS

Egg Rock

eggrock2

This golf-ball-sized object, informally named “Egg Rock,” is an iron-nickel meteorite. Iron-nickel meteorites are a common class of space rocks found on Earth, and previous examples have been found on Mars, but Egg Rock is the first on Mars to be examined with a laser-firing spectrometer.

The laser pulses on Oct. 30, 2016, induced bursts of glowing gas at the target, and ChemCam’s spectrometer read the wavelengths of light from those bursts to gain information about the target’s composition. The laser pulses also burned through the dark outer surface, exposing bright interior material.

If you click the image above you will get a  colorized view from the Chemistry and Camera (ChemCam) instrument on NASA’s Curiosity Mars rover shows a grid of shiny dots where ChemCam had fired laser pulses used for determining the chemical elements in the target’s composition.

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

Wharton Ridge

Here is an image taken of the western rim of Endeavour Crater on Mars. This image contains a portion of “Marathon Valley and “Wharton Ridge” and was taken in August 2016 by the rover Opportunity!

oppyinseptember16

From the caption released with the image:

The full extent of Wharton Ridge is visible, with the floor of Endeavour Crater beyond it and the far wall of the crater in the distant background. Near the right edge of the scene is “Lewis and Clark Gap,” through which Opportunity crossed from Marathon Valley to “Bitterroot Valley” in September 2016.

Before the rover departed Marathon Valley, its panoramic camera (Pancam) acquired the component images for this scene on Aug. 30, 2016, during the 4,480th Martian day, or sol, of Opportunity’s work on Mars.

Opportunity’s science team chose the ridge’s name to honor the memory of Robert A. Wharton (1951-2012), an astrobiologist who was a pioneer in the use of terrestrial analog environments, particularly in Antarctica, to study scientific problems connected to the habitability of Mars. Over the course of his career, he was a visiting senior scientist at NASA Headquarters, vice president for research at the Desert Research Institute, provost at Idaho State University, and president of the South Dakota School of Mines and Technology.

The view spans from east-northeast at left to southeast at right. It merges exposures taken through three of the Pancam’s color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). It is presented in approximately true color.

Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.