Friday, October 17, 2014

Wdowiak Ridge

This vista from NASA's Mars Exploration Rover Opportunity shows "Wdowiak Ridge," from left foreground to center, as part of a northward look with the rover's tracks visible at right.

Opportunity's panoramic camera (Pancam) recorded the component images for this mosaic on September 17, 2014, during the 3,786th Martian day, or sol, of Opportunity's work on Mars.

The ridge stands prominently on the western rim of Endeavour crater, about 200 yards or meters west of the rim's main crest line. Its informal name is a tribute to Opportunity science team member Thomas J. Wdowiak (1939-2013).

This panorama spans about 70 compass degrees from north-northwest on the left to east-northeast on the right. Wdowiak Ridge rises steeply about 40 feet from base to top. It extends about 500 feet (150 meters) in length. For scale, the distance between Opportunity's parallel wheel tracks is about 3.3 feet (1 meter).

Wdowiak Ridge is visible from overhead in the map at, from the northeastern end near the rover's Sol 3751 location to Odyssey Crater near the rover's Sol 3789 location.

This version of the image is presented in approximate true color by combing 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).

Image credit: NASA/JPL-Caltech/Cornell University/Arizona State University

Note: For more information, see PIA18615: Opportunity's Northward View of 'Wdowiak Ridge' (False Color), PIA18616: Opportunity's Northward View of 'Wdowiak Ridge' (Stereo), and NASA's Opportunity Rover Gets Panorama Image at 'Wdowiak Ridge'.

Friday, October 10, 2014

Preparing for Comet Siding Spring (C/2013 A1)

This artist's concept shows NASA's Mars orbiters lining up behind the Red Planet for their "duck and cover" maneuver to shield them from comet dust that may result from the close flyby of comet Siding Spring (C/2013 A1) on October 19, 2014.

The comet's nucleus will miss Mars by about 87,000 miles (139,500 kilometers), shedding material as it hurtles by at about 126,000 miles per hour miles (56 kilometers per second), relative to Mars and Mars-orbiting spacecraft.

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data. The NASA orbiters at Mars are Mars Reconnaissance Orbiter, Mars Odyssey and MAVEN.

Image credit: NASA/JPL-Caltech

Note: For more information, see PIA18612: View of Comet Siding Spring from Southern Hemisphere (Artist's Concept) and NASA Prepares its Science Fleet for October 19 Mars Comet Encounter.

Wednesday, October 8, 2014

Thumbprint Ridges at Planum Australe

While yesterday's VIS image showed a texture of oval depressions (swiss cheese), today's VIS image shows a linear surface texture of the south polar cap. This texture is described as looking like a thumbprint.

Orbit Number: 56378 Latitude: -77.7252 Longitude: 184.825 Instrument: VIS Captured: 2014-08-29 21:37

Photo credit: NASA/JPL-Caltech/Arizona State University

Tuesday, October 7, 2014

Swiss Cheese Terrain at Planum Australe

This VIS image of the south pole shows a surface with numerous oval depressions. This texture has been described as looking like swiss cheese.

Orbit Number: 56300 Latitude: -86.7211 Longitude: 355.028 Instrument: VIS Captured: 2014-08-23 11:26

Photo credit: NASA/JPL-Caltech/Arizona State University

Monday, October 6, 2014

Bright Slope Streaks in Arabia Terra

This observation shows bright and dark slope streaks in craters in the Arabia Terra region.

Slope streak formation is among the few known processes currently active on Mars. The cause of slope streaks is still debated, and both dry and wet processes have been proposed to explain their formation. They are most commonly believed to form by gravity-driven movement of extremely dry sand or very fine-grained dust in an almost fluid-like manner (analogous to a terrestrial snow avalanche) exposing darker underlying material.

The darkest slope streaks are the youngest and can be seen to cross cut and lie on top of the older and lighter-toned streaks. The lighter-toned streaks are believed to be dark streaks that are brightening with time as new dust is deposited on their surface. Where they occur, dark slope streaks are typically more plentiful than the bright streaks. However in this area, distinct bright slope streaks appear to be more plentiful, especially in the two smaller craters on either side of the larger crater in the center of the image.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18819: Bright Slope Streaks in Arabia Terra.

Sunday, October 5, 2014

Continual Dune and Ripple Migration in Nili Patera

Nili Patera is a region on Mars in which dunes and ripples are moving rapidly. HiRISE continues to monitor this area every couple of months to see changes over seasonal and annual time scales.

Here we see obvious activity over a span of less than two Earth years. Three prominent changes are obvious: 1) the dunes are migrating, with position differences of a few meters in some areas; 2) the ripples on the surfaces of the dunes have undergone so much change that they cannot be reliably tracked over this time interval; and 3) the lee faces of the dunes exhibit new avalanches.

These results show that Nili Patera, and other regions on Mars, are areas of active sand migration and landscape erosion.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18818: Continual Dune and Ripple Migration in Nili Patera.

Saturday, October 4, 2014

Erosion on the Southern Flank of Apollinaris Mons

This VIS image of Apollineris Mons shows erosion of the materials on its southern flank.

Orbit Number: 56490 Latitude: -9.93411 Longitude: 174.889 Instrument: VIS Captured: 2014-09-08 03:18

Photo credit: NASA/JPL-Caltech/Arizona State University

Dome and Barchan Dunes in Newton Crater

This observation shows a small sand dune field on the floor of Newton Crater, an approximately 300 kilometer (130 mile) wide crater in the southern hemisphere of Mars.

The image shows both dome and barchan dunes. Both these types of dunes are also found on Earth. Barchan dunes in particular are common on Earth, and are generally crescent-shaped with a steep slip face bordered by horns oriented in the downwind direction. Barchan dunes form by unidirectional winds and are good indicators of the dominant wind direction.

In this case, the horns of the barchan dunes are not very distinct but appear to indicate that the strongest winds blew approximately southeast to northwest. Note the pattern the dunes form around a bright streak in the downwind direction behind a crater in the center of the image.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18820: Dome and Barchan Dunes in Newton Crater.

Friday, October 3, 2014

Hebes Chasma

This VIS image shows a portion of Hebes Chasma.

Orbit Number: 56299 Latitude: -1.25997 Longitude: 282.713 Instrument: VIS Captured: 2014-08-23 09:56

Photo credit: NASA/JPL-Caltech/Arizona State University

Oxia Planum Near Coogoon Vallis

Oxia Planum is broad clay-bearing surface between Mawrth and Ares Vallis that has been proposed as a future landing site on Mars.

Remnants of a possible fan or delta near the outlet of Coogoon Vallis is a potential science target at this location.

This is a stereo pair with ESP_037136_1985.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18817: Possible Future Mars Landing Site in Oxia Planum.

Thursday, October 2, 2014

Tithonium Chasma and Ius Chasma

This VIS image spans from Tithonium Chasma (top of image) to Ius Chasma (bottom of image).

Orbit Number: 56187 Latitude: -6.18316 Longitude: 273.792 Instrument: VIS Captured: 2014-08-14 04:36

Photo credit: NASA/JPL-Caltech/Arizona State University

Wednesday, October 1, 2014

Slope Streaks in Amazonis Planitia

This VIS image shows dark slope streaks on the inner rim of an unnamed crater in Amazonis Planitia.

Orbit Number: 56152 Latitude: 13.5003 Longitude: 200.567 Instrument: VIS Captured: 2014-08-11 07:33

Photo credit: NASA/JPL-Caltech/Arizona State University