The image above shows three dust devils in the Ganges Chasma (Valles Marineris) on Mars. It was taken by the HiRISE camera on board the Mars Reconnaissance orbiter. There were actually eight dust devils captured in an image you can see here from NASA.
Here is most of the caption released with the image:
Both of these factors help warm the surface and generate convection in the air above. The surface is streaked with the faint tracks of earlier dust devils. A pair of dust devils appears together at top right, spaced only 250 meters apart. These two have quite different morphologies. The bigger one (on the right) is about 100 meters in diameter and is shaped like a doughnut with a hole in the middle. Its smaller companion is more compact and plume-like, but it too has a small hole in the center, where the air pressure is lowest. It may be that the smaller dust devil is younger than the larger one. A row of four dust devils are in the middle of the color strip, separated by about 900 meters from one another.
This image might answer some interesting questions about the behavior of dust devils. Dust devils are theoretically expected to migrate uphill on a sloping surface, or migrate downwind when there is a breeze. Where they are found close together in pairs, they are expected to rotate in opposite directions. HiRISE color observations can be used to determine the direction of rotation and-for fast moving dust devils-the direction of their travel. This is because the different color observations (infrared, red, and blue) are taken at slightly different times. The differences between the earliest color observation and the last tell us about the changes that took place during that time interval.
All this requires careful analysis, but if these dust devils are moving fast enough, and spaced closely enough, these here might display some interesting “social dynamics,” possibly marching together and rotating in alternating directions.
Pretty exciting news! Mars seems to be at least a little wet. The NASA account is below. Makes me wonder if we can get rover there to directly sample the area. If it were only that simple. Time for a “glide-in” rover of some type.
I wonder if the researchers have speculated on amount of water seeping up based on the environmental conditions present – what is the minimum amount of water in a brine concentration to resist freezing at minus 23 C / minus 10 F to make such wet spot.
How much of that moisture is lost to the atmosphere is another question, could it be the planet is still drying out?
Dark narrow streaks, called “recurring slope lineae,” emanate from the walls of Garni Crater on Mars, in this view constructed from observations by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter.
The dark streaks here are up to few hundred yards, or meters, long. They are hypothesized to be formed by flow of briny liquid water on Mars.
The image was produced by first creating a 3-D computer model (a digital terrain map) of the area based on stereo information from two HiRISE observations, and then draping an image over the land-shape model. The vertical dimension is exaggerated by a factor of 1.5 compared to horizontal dimensions. The draped image is a red waveband (monochrome) product from HiRISE observation ESP_031059_1685, taken on March 12, 2013 at 11.5 degrees south latitude, 290.3 degrees east longitude. Other image products from this observation are at http://hirise.lpl.arizona.edu/ESP_031059_1685.
The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter Project and Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington.
Very impressive sand dunes on Mars. The Mars Reconnaissance Orbiter took this image with the amazing HiRISE Imager. These dunes are inside a crater for a larger perspective have a look at this “Map Projected Browse Image“.
The original caption:
The workings of the Martian winds are visible in this image of sand dunes trapped inside an unnamed crater in southern Terra Cimmeria.
Many of the craters in the Southern highlands of Mars contain sand dunes, and HiRISE is still in the process of mapping these dunes and determining how active they are today. So far, the dunes in these craters appear to be a mixed bunch, with some dunes actively advancing while others seem to be frozen in place. This image will be compared to a previous picture, to see how these dunes have changed since 2008.
The sand dunes are the large, branched ridges and dark patches that are conspicuous against the bright background, particularly in the northwest corner of our picture. There are also signs of two other wind-related processes: smaller, brighter ridges line the floor of the crater in regularly spaced rows. These are also windblown deposits, mysterious â€œtransverse aeolian ridgesâ€ or TARs that are more common in the Martian tropics. Faint, irregular dark lines cross the dunes and the TARs, marking the tracks of dust devils that vacuum the surface during southern summer. So, which came first? We can untangle the history of these processes by looking at the picture more closely.
Deposits of impact glass have been preserved in Martian craters, including Alga Crater, shown here. Detection of the impact glass by researchers at Brown University, Providence, Rhode Island, is based on data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on NASA’s Mars Reconnaissance Orbiter.
In color coding based on analysis of CRISM spectra, green indicates the presence of glass. (Blues are pyroxene; reds are olivine.) Impact glass forms in the heat of a violent impact that excavates a crater. Impact glass found on Earth can preserve evidence about ancient life. A deposit of impact glass on Mars could be a good place to look for signs of past life on that planet.
This view shows Alga Crater’s central peak, which is about 3 miles (5 kilometers) wide within the 12-mile (19-kilometer) diameter of this southern-hemisphere crater. The information from CRISM is shown over a terrain model and image, based on observations by the High Resolution Imaging Science Experiment (HiRISE) camera. The vertical dimension is exaggerated by a factor of two.
The Mars Reconnaissance Orbiter has been using CRISM, HiRISE and four other instruments to investigate Mars since 2006. The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, led the work to build the CRISM instrument and operates CRISM in coordination with an international team of researchers from universities, government and the private sector. HiRISE is operated by the University of Arizona, Tucson, and was built by Ball Aerospace & Technologies Corp., Boulder, Colorado.
NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter Project for NASA’s Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter and collaborates with JPL to operate it.
Image Credit: NASA/JPL-Caltech/JHUAPL/Univ. of Arizona
Check it out — a boulder track on Mars. No speculation on what dislodged the boulder. Perhaps a close meteor strike making one of the larger craters shook it loose or it could even be ejecta from an impact like some of the ones we see on our moon. If you follow the track to the origin there almost looks like a small pit at the beginning.
A path resembling a dotted line from the upper left to middle right of this image is the track left by an irregularly shaped, oblong boulder as it tumbled down a slope on Mars before coming to rest in an upright attitude at the downhill end of the track. The High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter recorded this view on July 14, 2014.
The boulder’s trail down the slope is about one-third of a mile (about 500 meters) long. The trail has an odd repeating pattern, suggesting the boulder could not roll straight due to its shape.
Calculated from the length of the shadow cast by the rock and the known angle of sunlight during this afternoon exposure, the height of the boulder is about 20 feet (6 meters). Its width as seen from overhead is only about 11.5 feet (3.5 meters), so it indeed has an irregular shape. It came to rest with its long axis pointed up.
Two parallel tracks left by the wheels of NASA’s Curiosity Mars rover cross rugged ground in this portion of a Dec. 11, 2013, observation by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. The rover itself does not appear in this part of the HiRISE observation.