Saturday, December 20, 2014

Daga Vallis

The THEMIS VIS camera contains 5 filters. The data from different filters can be combined in multiple ways to create a false color image. These false color images may reveal subtle variations of the surface not easily identified in a single band image. Today's false color image shows part of Daga Vallis on Eos Mensa.

Orbit Number: 2012 Latitude: -11.8784 Longitude: 317.167 Instrument: VIS Captured: 2002-05-29 04:14

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

Wednesday, December 17, 2014

Possible Methane Sources and Sinks

This illustration portrays possible ways that methane might be added to Mars' atmosphere (sources) and removed from the atmosphere (sinks). NASA's Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur in the modern environment of Mars.

A molecule of methane consists of one atom of carbon and four atoms of hydrogen. Methane can be generated by microbes and can also be generated by processes that do not require life, such as reactions between water and olivine (or pyroxene) rock. Ultraviolet radiation (UV) can induce reactions that generate methane from other organic chemicals produced by either biological or non-biological processes, such as comet dust falling on Mars. Methane generated underground in the distant or recent past might be stored within lattice-structured methane hydrates called clathrates, and released by the clathrates at a later time, so that methane being released to the atmosphere today might have formed in the past.

Winds on Mars can quickly distribute methane coming from any individual source, reducing localized concentration of methane. Methane can be removed from the atmosphere by sunlight-induced reactions (photochemistry). These reactions can oxidize the methane, through intermediary chemicals such as formaldehyde and methanol, into carbon dioxide, the predominant ingredient in Mars' atmosphere.

Image credit: NASA/JPL-Caltech/SAM-GSFC/University of Michigan

Note: For more information, see:
* PIA19086: Tunable Laser Spectrometer on NASA's Curiosity Mars Rover
* PIA19087: Methane Measurements by NASA's Curiosity in Mars' Gale Crater
* PIA19089: Some Data from Detection of Organics in a Rock on Mars
* PIA19090: Comparing 'Cumberland' With Other Samples Analyzed by Curiosity
* PIA19091: Mars Has Ways to Make Organics Hard to Find
* NASA Rover Finds Active and Ancient Organic Chemistry on Mars
* How NASA Curiosity Instrument Made First Detection of Organic Matter on Mars
* Curiosity Detects Methane Spike on Mars

Friday, December 12, 2014

Impact Crater in Morava Valles

Morava Valles is a small outflow channel in the Margaritifer Sinus region of Mars. Several of the interior channels of Morava emanate from a localized region of terrain that is caving in, also called “subsidence.”

This region, comprised of jumbled blocks of flat-topped hills, is known as chaotic terrain. These channels, which emerge from the chaotic region, are separated by elongated hills that coalesce into a single channel before disappearing into the Margaritifer Chaos to the north. Chaotic terrains are thought to be the regions where ground water erupted catastrophically onto the surface, forming highly erosive flows that carved the outflow channels. The hills just downstream of the chaotic source region were shaped into streamlined islands by the erosive flows, forming blunt rounded ends in the upstream direction and tapering towards the north in the downstream direction.

Although windblown sediments now cover the original flood-carved channel floor in a sea of dunes, a 1.5 kilometer diameter impact crater provides a window into the sediment on the channel floor. The crater exposes several layers along its upper walls including a distinct bouldery layer just below the mantle of windblown sediments. These boulders may have originated from the eruption site and were transported and emplaced on the channel floor by high energy floods. Alternatively, these bouldery layers may be lava that subsequently flowed across the flood scarred channel floors.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA19116: Seeing Beneath the Surface in Morava Valles.

Tuesday, December 9, 2014

Gale Crater Lake

This illustration depicts a lake of water partially filling Mars' Gale Crater, receiving runoff from snow melting on the crater's northern rim. Evidence of ancient streams, deltas and lakes that NASA's Curiosity Mars rover mission has found in the patterns of sedimentary deposits in Gale Crater suggests the crater held a lake such as this more than three billion years ago, filling and drying in multiple cycles over tens of millions of years.

Gale Crater is 96 miles (154 kilometers) in diameter. This view is looking toward the southeast. The land surface in this illustration is the area's modern shape. Three billion years ago, the rim would have been higher and less eroded. A large layered mountain, Mount Sharp, now stands in the middle of Gale Crater. Accumulation of sediments in lakes, deltas, streams and wind-blown deposits is proposed to have formed the layers making up the lower portion of the mountain. When the crater first held a lake, it might have had central peak, much smaller than Mount Sharp, formed as a rebound from the impact that excavated the crater. Such a peak might have appeared as an island in the lake.

Illustration credit: NASA/JPL-Caltech

Note: For more information, see:
* PIA19067: Curiosity Mars Rover's Route from Landing to Base of Mount Sharp
* PIA19068: Inclined Martian Sandstone Beds Near 'Kimberley'
* PIA19069: Bedding Pattern Interpreted as Martian Delta Deposition
* PIA19070: Sets of Beds Inclined Toward Mount Sharp
* PIA19071: How a Delta Forms Where River Meets Lake
* PIA19072: Sol 696 (July 22, 2014), Left
* PIA19073: Multiple Deltas Built Out Over Time
* PIA19074: Sedimentary Signs of a Martian Lakebed
* PIA19075: Thin-Laminated Rock in 'Pahrump Hills' Outcrop
* PIA19076: Cross-Bedding at 'Whale Rock'
* PIA19077: Crystals May Have Formed in Drying Martian Lake
* PIA19078: Sediment Accumulation in Dry and Wet Periods
* PIA19079: Sedimentation and Erosion in Gale Crater, Mars
* PIA19081: Martian Rock's Evidence of Lake Currents
* NASA's Curiosity Rover Finds Clues to How Water Helped Shape Martian Landscape
* Mars Mountain was All Wet

Monday, December 8, 2014

Enigmatic Feature in Athabasca Lava Flows

What is this enigmatic landform?

The circular feature is nearly 2 kilometers (1.2 miles) wide. It looks like a circular island surrounded by a "sea" of smooth-looking lava flows. The Athabasca region contains some of the youngest lava flows on Mars. Therefore, it is highly possible that volcanism played a role in creating this feature.

Perhaps lava has intruded underneath this mound and pushed it up from beneath. It looks as if material is missing from the mound, so it is also possible that there was a significant amount of ice in the mound that was driven out by the heat of the lava. There are an array of features like this in the region that continue to puzzle scientists.

We hope that close inspection of this HiRISE image, and others around it, will provide some clues regarding its formation.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18932: An Enigmatic Feature in Athabasca Lava Flows.

Sunday, December 7, 2014

Clays Along the Coprates Chasma Plateau

This image shows exposures of deposits along the plateau just to the south of Coprates Chasma.

Whereas Coprates Chasma and many of the other chasmata of Valles Marineris contain kilometer-thick light-toned mounds made up of sulfates, several of the deposits along the plateau have signatures of clays. This indicates that water was here for extensive periods of time to cause the plains to weather and alter into clays.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18933: Clays along the Coprates Chasma Plateau.

Saturday, December 6, 2014

Dunes and Wind Streaks in Arabia Terra

Arabia Terra is one of the more dusty regions on Mars, where ever-falling red dust covers the surface allowing only minor variations in color and tone. One exception is when wind-driven, dark-toned sand moves across the surface ejecting the bright dust into the atmosphere to reveal the dust-free surface below.

This HiRISE image shows sand dunes with surrounding larger tear drop-shaped light streaks pointing west (or, to the left). This orientation, along with the morphology of the local dunes, indicates winds from the east have stripped sand particles off the dunes and carried them downwind to form these light streaks. More importantly, active sand has a role in the slow erosion of the rocks here and the overall landscape evolution of the region.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18931: Dunes and Wind Streaks in Arabia Terra.

Friday, December 5, 2014

Braided TARs in Syrtis Major

Transverse aeolian ridges (TARs) are commonly found throughout the Martian tropics, including rocky regions such as Syrtis Major that are largely devoid of dust.

These bright wind-blown ripples most often occur in simple sets of ridges with regular size and spacing. Typical TARs stand a few meters tall and have a wavelength (that is to say, separation) of 30 to 60 meters. HiRISE has not detected any changes among the TARs today, suggesting that they are inactive.

In this scene, we see TARs with a highly unusual morphology. Instead of single ridges, we see sets of small ridges that are separated by about 50 meters. The smaller ripples are spaced only 5 to 8 meters apart. Between the smaller ripples are even smaller striations that are perpendicular to the ridge crests with regular spacings of less than 2 meters.

This image raises a number of puzzling questions. Why are the ripples organized into two distinct wavelengths? Did the different wavelengths result from different processes or from different conditions? When did these wavelength-specific conditions or processes take place? Did they occur together, or did they alternate, or did one take place after the other? Were the processes depositional or erosional, or both?

The complexity of Martian TARs makes us think twice about any single explanation for their origin.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18930: Braided TARs in Syrtis Major.

Thursday, December 4, 2014

False Color Arsia Mons

This false color image shows part of the summit caldera of Arsia Mons. The mottled bluish tones are from clouds.

Orbit Number: 56650 Latitude: -9.51318 Longitude: 239.933 Instrument: VIS Captured: 2014-09-21 07:27

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

Wednesday, December 3, 2014

False Color Noctis Labyrinthus

This false color image covers part of Noctis Labyrinthus. The bluish tone in the lower elevation depressions may indicate atmospheric haze.

Orbit Number: 56612 Latitude: -5.85669 Longitude: 255.491 Instrument: VIS Captured: 2014-09-18 04:23

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

Tuesday, December 2, 2014

False Color Claritas Fossae

This false color image shows part of Claritas Fossae.

Orbit Number: 56562 Latitude: -42.1269 Longitude: 263.184 Instrument: VIS Captured: 2014-09-14 01:23

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

Saturday, November 29, 2014

False Color Tithonium and Ius Chasmata

This false color image of the region including both Tithonium and Ius Chasmata includes a bluish region in both canyons. This may indicate an atmospheric haze. The potential haze appears to be more widespread in Ius Chasma.

Orbit Number: 56524 Latitude: -5.5587 Longitude: 273.654 Instrument: VIS Captured: 2014-09-10 22:30

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

Friday, November 28, 2014

False Color Ascraeus Mons

Today's VIS image is a false color image of part of the northern flank of Ascreaus Mons. The bluish section at the top of the image may indicate an atmospheric haze.

Orbit Number: 56512 Latitude: 13.2761 Longitude: 257.162 Instrument: VIS Captured: 2014-09-09 22:53

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

Thursday, November 20, 2014

Pink Cliffs

This small ridge, about 3 feet (1 meter) long, appears to resist wind erosion more than the flatter plates around it. Such differences are among the rock characteristics that NASA's Curiosity Mars rover is examining at selected targets at the base of Mount Sharp.

The ridge pictured here, called "Pink Cliffs," is within the "Pahrump Hills" outcrop forming part of the basal layer of the mountain. This view is a mosaic of exposures acquired by Curiosity's Mast Camera (Mastcam) shortly before a two-week walkabout up the outcrop, scouting to select which targets to examine in greater detail during a second pass.

Pink Cliffs is one of the targets chosen for closer inspection. This image combines several frames taken with the Mastcam on October 7, 2014, the 771st Martian day, or sol of Curiosity's work on Mars. The color has been approximately white-balanced to resemble how the scene would appear under daytime lighting conditions on Earth.

Figure 1 is a version with a scale bar overlaid on the image.

An image showing the Pahrump Hills walkabout route is at PIA19039. An overhead map showing the walkabout drives, from Sol 780 (Oct. 16) to Sol 794 (Oct. 30) is at

Image credit: NASA/JPL-Caltech/MSSS

Wednesday, November 19, 2014

Spring in Inca City V

A significant event has occurred in Inca City. The layer of seasonal ice has started to develop long cracks. This is visible in the orange-colored band adjacent to the araneiforms. Fans of dust are emerging from long linear cracks. The cracks form when large plates of ice have no easily ruptured weak spots to release the pressure from gas building up underneath, so the ice simply cracks.

There are also more fans on the ridge at the top of the image, and more have appeared in between the araneiforms. We do not have any analogous processes occurring naturally on Earth: this is truly Martian.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18896: Spring in Inca City V.

Tuesday, November 18, 2014

Spring in Inca City IV

At certain times in spring, fans take on a gray or blue appearance. This is the time in Inca City when this phenomenon happens.

On the ridge at the top of the image fans have lengthened and now look more gray than the blotches on the araneiforms. At the bottom of the image they are distinctly blue in color.

Two theories have been suggested: perhaps fine particles sink into the seasonal layer of ice so they no longer appear dark. Or, maybe the gas that is released from under the ice condenses and falls to the surface as a bright fresh layer of frost. It is quite likely that both of these theories are correct.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18895: Spring in Inca City IV.

Monday, November 17, 2014

Spring in Inca City III

In Inca City another week has passed, and there are a few more fans on the ridge. We are studying the sequence of spring activity with the help of citizen scientists at the Planetfour website, sponsored by Zooniverse.

Citizens of planet Earth log on and identify and measure fans and blotches in the South polar region of Mars imaged by HiRISE. With their help we can study the polar weather by looking at how the fan directions change through the spring.

We see how the number of fans and blotches depends on the thickness of the ice layer and how high the sun is in the sky. If you would like to be a part of this endeavor join us at

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18894: Spring in Inca City III.

Sunday, November 16, 2014

Spring in Inca City II

It is about two weeks later in Inca City and the season is officially spring. Numerous changes have occurred. Large blotches of dust cover the araneiforms. Dark spots on the ridge show places where the seasonal polar ice cap has ruptured, releasing gas and fine material from the surface below.

At the bottom of the image fans point in more than one direction from a single source, showing that the wind has changed direction while gas and dust were flowing out. Was the flow continuous or has the vent opened and closed?

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18893: Spring in Inca City II.

Saturday, November 15, 2014

Spring in Inca City I

Every winter a layer of carbon dioxide ice — or, dry ice — condenses in the Southern polar region, forming a seasonal polar cap less than 1 meter deep. Early in the spring the ice layer begins to sublimate (going directly from a solid to gas) from the top and bottom of the ice layer. Under the ice gas pressure builds up until a weak spot in the ice layer ruptures. The gas rushes out and as it escapes it erodes a bit of the surface.

Fine particles are carried by the gas to the top of the ice and then fall out in fan-shaped deposits. The direction of the fan shows the direction either of the wind or down the slope. If the wind is not blowing a dark blotch settles around the spot the gas escaped.

This region is known informally as Inca City, and it has a series of distinctive ridges. On the floor between the ridges are radially organized channels, known colloquially as spiders, more formally called "araneiforms." The channels have been carved in the surface over many years by the escaping pressurized gas. Every spring they widen just a bit.

This was the first image to be acquired after the sun rose on Inca City, marking the end to polar night. A few fans are visible emerging from the araneiforms.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18892: Spring in Inca City I.

Sunday, November 2, 2014

Partially-Filled Impact Crater in Elysium Planitia

This image shows an impact crater that was cut by lava in the Elysium Planitia region of Mars. The relatively flat, shallow floor, rough surface texture, and possible cooling cracks seem to indicate that the crater was partially filled with lava. The northern part of the image also shows a more extensive lava flow deposit that surrounds the impact ejecta of the largest impact crater in the image.

Which way did the lava flow? It might appear that the lava flowed from the north through the channel into the partially filled crater. However, if you look at the anaglyph with your red and blue 3D glasses, it becomes clear that the partially filled crater sits on top of the large crater's ejecta blanket, making it higher than the lava flow to the north. Since lava does not flow uphill, that means the explanation isn't so simple.

We have seen much evidence for lava flows in this region that flowed to much higher levels than the present surface, then deflated or drained away. That may have happened here: lava flowed from from north to south to fill this crater, but then it drained back to the north, carving this channel.

The topographic information that we gained from having a stereo pair let us answer a question that we could not have with only a single image. This is a great example of why we take stereo images, where the two images are used to make a 3D image.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18887: Which Way is Up?

Saturday, November 1, 2014

Hardened Dunes in Arcadia Planitia

HiRISE, with its high resolution and 8 years in orbit about Mars, has shown that many dunes and ripples on the planet are active. This demonstrates that in some areas sand is loose enough and winds strong enough, that significant change can occur.

Nevertheless, other Martian dunes are clearly *inactive*. This image in Arcadia Planitia shows dunes in a crater. Unlike active dunes on the planet, those here are bright, and, zooming in, there are several lines of evidence indicating that the dunes have become indurated, that is, hardened into cohesive sediment or even into sandstone rock. For example, the dune field at the southern edge is cut off by a step cliff, indicating erosion of hard material. Although fine scale ripples on the original dune surface are preserved, we also see large scale fluting from southwest to northeast, a common texture associated with wind-induced sand abrasion.

How these dunes became indurated is unknown. One possibility is that this area of Mars was buried and then exhumed, a process that seems to have occurred many times in the Martian past over various areas of the planet. During burial, compaction and possibly ground water circulation would have indurated the dunes, leaving them as a hard sandstone that, when exhumed, was subsequently partially eroded.

Note: a version of the cutout is with only the scale bar is here.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18890: Hardened Dunes in Arcadia Planitia.

Friday, October 31, 2014

Sand Forming at a Channel in Athabasca Valles

This image shows a small channel cutting into young volcanic lavas in a region where massive catastrophic flooding took place in the relatively recent past. The Athabasca Valles region includes a vast lava flow, thought to be the youngest on Mars, with even younger outflow channels that were carved by running water. The source of the water is believed to be the Cerberus Fossae valleys to the north, which may have penetrated to an over-pressurized aquifer in the subsurface.

Nowadays, erosion by gravity, wind, and frost gradually wears down the rims of the outflow channels. In this scene, we see dark materials along the channel rim that were probably exposed by this erosion. The dark materials are less red than the surrounding surface and so they appear blue in this enhanced color picture. Viewed close up, the dark materials show ripples that suggest they are made up of mobile sand. It is possible that this sand originated elsewhere and simply collected where we see it today, but the fact that sand is not found elsewhere in the scene suggest to us that it is eroding out of the volcanic layers at the retreating rim of the channel.

Sand sources are important because mobile sand grains have only a limited lifetime, wearing down and chipping apart each time they impact the surface. Erosion of the volcanic materials in this region may provide sands to replace those that are destroyed. Few such sand sources have so far been identified on Mars.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18889: Sand Sources Near Athabasca Valles.

Thursday, October 30, 2014

Possible Landing Site of the Mars 3 Lander

Despite the recent successes of missions landing on Mars, like the Mars Science Laboratory (Curiosity) or the arrival of new satellites, such as India's MOM orbiter, the Red Planet is also a graveyard of failed missions.

The Soviet Mars 2 lander was the first man-made object to touch the surface of the Red Planet when it crashed landed on 27 November 1971. It is believed that the descent stage malfunctioned after the lander entered the atmosphere at too steep an angle. Attempts to contact the probe after the crash were unsuccessful.

HiRISE acquired this image to aid in the search for the missing lander. If the Mars 2 debris field is found it could serve as a future landing location for a mission to study the effects of crash landing on the Martian surface and effects of aging on man-made objects.

This caption is based on the original science rationale. To date, the debris field has not been located, but this spot was noted as a probable location for the Mars 3 lander.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18888: Search for the Mars 2 Debris Field. The Mars 3 Lander is believed to have landed in Ptolemaeus Crater.

Saturday, October 18, 2014

Perennial Frost in a Vastitas Borealis Crater

Most surface ice on Mars is temporary. The polar layered deposits are thick stacks of permanent water ice at each pole, and the South Polar residual cap may be a permanent (although dynamic) layer of carbon dioxide ice. However, at lower latitudes, seasonal frost (mostly carbon dioxide, but some water ice) comes and goes each year.

Some outliers of water ice are found near the North Polar layered deposits. In many cases these have accumulated significant thickness, as in Louth Crater. In this case, a thin layer of bright frost was visible in a HiRISE image in early summer, covering part of the wall of a crater. However, the thickness was small—there is little visible effect on the topography of the crater. HiRISE monitored this location through the rest of the season and found that the frost remained all summer, so this is a perennial ice patch, although the edges shrank slightly over the summer.

Carbon dioxide is not stable under summer conditions, so this is likely a patch of water ice. It may be that it is in the early stages of accumulation, or that the equilibrium amount of ice in a small crater relatively far from the pole is thin.

A still-unexplained feature of this crater is the diffuse dark smudges visible on the crater floor. These resemble “defrosting spots” which are visible on carbon dioxide ice in the early spring, but they occur on frost-free areas and survive throughout the summer.

Image credit: NASA/JPL/University of Arizona

Note: This crater is located in Vastitas Borealis to the southwest of Korolev Crater. For more information, see PIA18832: Perennial Frost in a Crater on the Northern Plains.

Friday, October 17, 2014

Candor Chasma

Today's VIS image shows part of the floor of Candor Chasma.

Orbit Number: 56461 Latitude: -6.12623 Longitude: 290.797 Instrument: VIS Captured: 2014-09-05 18:01

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

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'.

Thursday, October 16, 2014

Mounds of Layered Material on the West Edge of Melas Chasma

Melas Chasma is the widest segment of the Valles Marineris canyon, and is an area where MRO has detected the presence of sulfates.

This image offers a view of an excellent contact between layered deposits that postdate the formation of Valles Marineris and possible deposits that predate the canyon's formation. The materials are near interior layered deposits that contain sulfates and likely have hydrated minerals. At high resolution, we can have more accurate mapping of the stratigraphic relationships and contacts. Enhanced color can help to differentiate between geologic units and for mapping of sulfates.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18830: Mounds of Layered Material on the West Edge of Melas Chasma.

Tuesday, October 14, 2014

Yardangs Near Memnonia Sulci

This region near Memnonia Sulci has been eroded by the wind to form linear ridges called yardangs. The two prominent directions of wind are recorded by the two directions of the ridges.

Orbit Number: 56315 Latitude: -10.4443 Longitude: 182.475 Instrument: VIS Captured: 2014-08-24 17:30

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

Saturday, October 11, 2014

Arsia Mons

Today's VIS image shows part of the caldera at the summit of Arsia Mons.

Orbit Number: 56313 Latitude: -9.26897 Longitude: 240.031 Instrument: VIS Captured: 2014-08-24 13:33

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

Friday, October 10, 2014

Angustus Labyrinthus

This region of linear, intersecting ridges near the south pole is called Angustus Labyrinthus.

Orbit Number: 56312 Latitude: -81.7259 Longitude: 297.097 Instrument: VIS Captured: 2014-08-24 11:11

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

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.

Thursday, October 9, 2014

Daedalia Planum

This VIS image shows a small portion of Daedalia Planum, a huge region of volcanic flows south of Arsia Mons.

Orbit Number: 56301 Latitude: -19.1718 Longitude: 227.546 Instrument: VIS Captured: 2014-08-23 13:47

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

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

Tuesday, September 30, 2014

Layering in Planum Australe

Today's VIS image shows layering in the south polar cap.

Orbit Number: 56263 Latitude: -82.7003 Longitude: 274.05 Instrument: VIS Captured: 2014-08-20 10:21

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

Saturday, September 27, 2014

Candor Chasma

This VIS image spans Candor Chasma.

Orbit Number: 56411 Latitude: -7.43707 Longitude: 293.113 Instrument: VIS Captured: 2014-09-01 15:12

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

Friday, September 26, 2014

Impact Crater in Southern Terra Sirenum

The ridge in today's VIS image is the rim of a crater near the south polar cap.

Orbit Number: 56402 Latitude: -78.815 Longitude: 214.37 Instrument: VIS Captured: 2014-08-31 21:02

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

Note: This impact crater is located in southern Terra Sirenum; the closest named feature is Reynolds Crater, which is some distance to the north.

Pahrump Hills Outcrop

This southeastward-looking vista from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover shows the "Pahrump Hills" outcrop and surrounding terrain seen from a position about 70 feet (20 meters) northwest of the outcrop.

The component images were acquired on September 17, 2014, during the 751st Martian day, or sol, of Curiosity's work on Mars. The rover team used these images to select a first drilling site on Pahrump Hills, which is part of the base layer of Mount Sharp. The selected drilling location is in the near portion of the pale outcrop to the right of the sand ripples.

The scene includes four distinct features:
1. Sand ripples in foreground, typical of those along the floors of valleys in this area within Gale Crater
2. The Pahrump Hills section of the Murray formation, where approximately 60 vertical feet (18 meters) of rock layers are exposed
3. A darker ridge off in the distance toward the left
4. Northwestern slopes of Mount Sharp in the background, where an abrupt transition is apparent between the buttes and valleys in the lower part and the tilted and carved beds of the upper part

This view combines several exposures taken by the Mastcam's left-eye camera. The color has been approximately white-balanced to resemble how the scene would appear under daytime lighting conditions on Earth.

Image credit: NASA/JPL-Caltech/MSSS

Note: For more information, see PIA18607: Curiosity Mars Rover's Route from Landing to 'Pahrump Hills', PIA18609: First Sampling Hole in Mount Sharp, PIA18610: Resistant Features in 'Pahrump Hills' Outcrop, and NASA Rover Drill Pulls First Taste From Mars Mountain.

Thursday, September 25, 2014

Impact Crater With Gullies in Terra Sirenum

Located on the floor of an unnamed crater in Terra Sirenum, the crater in the center of the VIS image has numerous gullies on the inner rim. An ejecta deposit from a near by crater is visible at the bottom on this image.

Orbit Number: 56451 Latitude: -38.1315 Longitude: 224.023 Instrument: VIS Captured: 2014-09-04 22:05

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

Wednesday, September 24, 2014

Channels in Terra Cimmeria

The unnamed channels in this VIS image are located in Terra Cimmeria.

Orbit Number: 56453 Latitude: -40.8943 Longitude: 166.72 Instrument: VIS Captured: 2014-09-05 02:01

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

Tuesday, September 23, 2014

Labou Vallis

Today's VIS image shows a portion of Labou Vallis.

Orbit Number: 56464 Latitude: -7.59742 Longitude: 204.493 Instrument: VIS Captured: 2014-09-05 23:56

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

Monday, September 22, 2014

MAVEN Enters Orbit Around Mars

This image shows an artist concept of NASA's Mars Atmosphere and Volatile Evolution (MAVEN) mission.

NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft successfully entered Mars' orbit at 7:24 p.m. PDT (10:24 p.m. EDT) Sunday, September 21, where it now will prepare to study the Red Planet's upper atmosphere as never done before. MAVEN is the first spacecraft dedicated to exploring the tenuous upper atmosphere of Mars.

"As the first orbiter dedicated to studying Mars' upper atmosphere, MAVEN will greatly improve our understanding of the history of the Martian atmosphere, how the climate has changed over time, and how that has influenced the evolution of the surface and the potential habitability of the planet," said NASA Administrator Charles Bolden. "It also will better inform a future mission to send humans to the Red Planet in the 2030s."

After a 10-month journey, confirmation of successful orbit insertion was received from MAVEN data observed at the Lockheed Martin operations center in Littleton, Colorado, as well as from tracking data monitored at NASA's Jet Propulsion Laboratory navigation facility in Pasadena, California. The telemetry and tracking data were received by NASA's Deep Space Network antenna station in Canberra, Australia.

"NASA has a long history of scientific discovery at Mars and the safe arrival of MAVEN opens another chapter," said John Grunsfeld, astronaut and associate administrator of the NASA Science Mission Directorate at the agency's Headquarters in Washington. "Maven will complement NASA's other Martian robotic explorers-and those of our partners around the globe-to answer some fundamental questions about Mars and life beyond Earth."

Following orbit insertion, MAVEN will begin a six-week commissioning phase that includes maneuvering into its final science orbit and testing the instruments and science-mapping commands. MAVEN then will begin its one Earth-year primary mission, taking measurements of the composition, structure and escape of gases in Mars' upper atmosphere and its interaction with the sun and solar wind.

"It's taken 11 years from the original concept for MAVEN to now having a spacecraft in orbit at Mars," said Bruce Jakosky, MAVEN principal investigator with the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder (CU/LASP). "I'm delighted to be here safely and successfully, and looking forward to starting our science mission."

The primary mission includes five "deep-dip" campaigns, in which MAVEN's periapsis, or lowest orbit altitude, will be lowered from 93 miles (150 kilometers) to about 77 miles (125 kilometers). These measurements will provide information down to where the upper and lower atmospheres meet, giving scientists a full profile of the upper tier.

"This was a very big day for MAVEN," said David Mitchell, MAVEN project manager from NASA's Goddard Space Flight Center, Greenbelt, Maryland. "We're very excited to join the constellation of spacecraft in orbit at Mars and on the surface of the Red Planet. The commissioning phase will keep the operations team busy for the next six weeks, and then we'll begin, at last, the science phase of the mission. Congratulations to the team for a job well done today."

MAVEN launched November 18, 2013, from Cape Canaveral Air Force Station in Florida, carrying three instrument packages. The Particles and Fields Package, built by the University of California at Berkeley with support from CU/LASP and Goddard, contains six instruments that will characterize the solar wind and the ionosphere of the planet. The Remote Sensing Package, built by CU/LASP, will identify characteristics present throughout the upper atmosphere and ionosphere. The Neutral Gas and Ion Mass Spectrometer, provided by Goddard, will measure the composition and isotopes of atomic particles.

The spacecraft's principal investigator is based at CU/LASP. The university provided two science instruments and leads science operations, as well as education and public outreach, for the mission.

NASA Goddard Space Flight Center manages the project and also provided two science instruments for the mission. Lockheed Martin built the spacecraft and is responsible for mission operations. The Space Sciences Laboratory at the University of California at Berkeley provided four science instruments for MAVEN. JPL provides navigation and Deep Space Network support, and Electra telecommunications relay hardware and operations. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Program for NASA.

Image credit: NASA/Goddard Space Flight Center

Note: For more information, see NASA Mars Spacecraft Ready for Sept. 21 Orbit Insertion and NASA's MAVEN Spacecraft Reaches Mars.