Thursday, January 31, 2013

Curiosity on Sol 157

This HiRISE observation was performed in conjunction with a CRISM observation so that they could get good spectral data on the scour zone created by the MSL descent rockets.

Our higher resolution HiRISE image will allow the CRISM team to compare their data with ours. The scour zone is where MSL touched down. The pair of bright white spots in the HiRISE image show the area immediately below where sky crane's rockets were pointed. Those areas were "blasted clean" and therefore show brightest. The larger dark scour zone is dark because the fine dust has been blown away from the area leaving darker materials.

However, we also captured Curiosity on its 157th Sol as it was exploring Yellowknife Bay and about to drill its first rock.

This is the first time that we've captured the rover tracks in color, and they show up as a pair of dark lines moving across the landscape.

Note: the above image is non map-projected, so approximate north is down.

Photo credit: NASA/JPL/University of Arizona

Tuesday, January 29, 2013

Channel East of Baetis Chaos

This unnamed channel is located east of Baetis Chaos.

Orbit Number: 48738 Latitude: -0.645607 Longitude: 301.829 Instrument: VIS Captured: 2012-12-09 03:40

Photo credit: NASA/JPL/Arizona State University

Drilling John Klein

The percussion drill in the turret of tools at the end of the robotic arm of NASA's Mars rover Curiosity has been positioned in contact with the rock surface in this image from the rover's front Hazard-Avoidance Camera (Hazcam).

The drill was positioned for pre-load testing, and the Hazcam recorded this image during the 170th Martian day, or sol, of Curiosity's work on Mars (January 27, 2013). Other tests with the drill are planned before the first drilling into a rock on Mars to collect a sample of rock material for analysis.

In this view, the drill is positioned on a target on a patch of flat, veined rock called "John Klein." The site is within the "Yellowknife Bay" area of Gale Crater.

Photo credit: NASA/JPL-Caltech

Note: For more information, see Curiosity Maneuver Prepares for Drilling

Butterfly Crater in Syrtis Major Planum

Emily Lakdawalla of the Planetary Society wrote a nice blog entry about her HiWish image here.

She requested stereo coverage, which is also available, and here's a resulting anaglyph cutout.

If you're interested in suggesting a potential target for us to image, consider setting up a HiWish account here.

This is a stereo pair with ESP_029999_1890.

Photo credit: NASA/JPL/University of Arizona

Note: This crater is located between Nili Patera to the west and Isidis Planitia to the east, in Syrtis Major Planum.

Monday, January 28, 2013

Banded Bedrock in Terra Sabaea

Terra Sabaea is the region of ancient highlands north of the Hellas impact basin.

The enhanced color image shows bands of bedrock with different colors. Such colorful bedrock is typical of ancient Mars, when water played a more active role in altering minerals, and multiple geologic processes were very active (impact, volcanism, fluvial, tectonic).

The ridges or bright or dark lines that cut across the layers mark faults, places where the crust fractured and accommodated motions. A field geologist could spend years mapping the geology of the terrain covered by this image.

Photo credit: NASA/JPL/University of Arizona

Sunday, January 27, 2013

Spring Fans in Planum Australe

At high latitudes every winter carbon dioxide condenses from Mars' atmosphere onto the surface forming a seasonal polar cap. In the spring, the Sun shines through this semi-translucent layer of dry ice and heats the ground below.

The ice sublimates (goes directly from ice to gas) on the underside of the seasonal ice layer and the gas is trapped. When the pressure is high enough the ice cracks and ruptures allowing the gas to escape. When the conditions are optimal this gas may condense locally near the source, forming a bright fan.

The dark fans are fine bits of surface material that get carried along by the escaping gas up to above the surface ice. Fine particles are also carried downwind and deposited in dark fans on top of the ice, where they may slowly sink into the ice. The rows of dark fans outline the original crack in the ice that allowed the gas to escape.

Photo credit: NASA/JPL/University of Arizona

Saturday, January 26, 2013

Yardangs in Elysium Planitia

The small parallel ridges in this VIS image were created by the erosive power of wind blown particles.

Orbit Number: 48580 Latitude: -0.208654 Longitude: 148.683 Instrument: VIS Captured: 2012-11-26 05:33

Photo credit: NASA/JPL/Arizona State University

Note: These yardangs are located in Elysium Planitia, to the north of Aeolis Mensae.

Stone Circles in Promethei Terra

This image covers a region southeast of the giant Hellas impact basin, which has distinctive properties in THEMIS temperature images.

The daytime temperatures are relatively cold while nighttime temperatures are relatively warm. This tells us that the surface material conducts heat efficiently, like rocks rather than fine-grained materials.

This image shows lots of boulders, and in places they form crude circular patterns. This could be due to the effects of many small impact craters (which we can no longer see, except perhaps for the boulder patterns). An alternative idea is that active processes on Mars can move large boulders (up to several meters in diameter) little by little over time.

There is almost certainly ice in the ground at this latitude (58 degrees south latitude), which expands and contracts with temperature changes. Those temperature stresses combined with the removal of fine-grained materials by the wind might be able to organize the boulders. Another idea is that in a recent past, climate the ice could seasonally melt, then re-freeze, which leads to stone circles in terrestrial permafrost (ground that is largely frozen throughout the year).

Photo credit: NASA/JPL/University of Arizona

Note: This image is located to the east of Secchi Crater in Promethei Terra.

Friday, January 25, 2013

Lava Flows from Pavonis Mons

The lava flows in this VIS image originated at Pavonis Mons.

Orbit Number: 48564 Latitude: -0.287967 Longitude: 250.006 Instrument: VIS Captured: 2012-11-24 21:57

Photo credit: NASA/JPL/Arizona State University

Sayunei at Night

This image of a Martian rock illuminated by white-light LEDs (light emitting diodes) is part of the first set of nighttime images taken by the Mars Hand Lens Imager (MAHLI) camera at the end of the robotic arm of NASA's Mars rover Curiosity. MAHLI took the images on January 22, 2012 (PST), after dark on the 165th Martian day, or sol, of the rover's work on Mars.

This rock target in the "Yellowknife Bay" area of Mars' Gale Crater is called "Sayunei." The image covers an area about 1.3 inches by 1 inch (3.4 by 2.5 centimeters). The illumination came from one of MAHLI's two groups of white LED pairs. This allowed surface features to cast shadows and provide textural detail.

Photo credit: NASA/JPL-Caltech/MSSS

Note: For more images in this series, see: PIA16712: MAHLI's First Night Imaging of Martian Rock Under Ultraviolet Lighting, PIA16713: First Night Image of MAHLI Calibration Target in White Lighting, and PIA16714: First Night Image of MAHLI Calibration Target Under Ultraviolet Lights. Also, Mars Rover Curiosity Uses Arm Camera at Night.

Sand Dunes in Olympia Undae Over Time

The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter snapped this series of false-color pictures of sand dunes in the north polar region of Mars. The area covered in each of the five panels is about 0.8 mile (1.3 kilometers) wide.

The progression begins at left (Panel A) in early spring, when the ground is covered by a seasonal layer of carbon dioxide ice (dry ice) about 2 feet thick. As spring progresses the ice cracks (Panel B), releasing dark sand from the dune below. When pressurized gas trapped below the ice layer is released, it carries along sand and dust to the top of the ice layer, where it is dropped in fan-shaped deposits downhill and downwind (panels C and D). The final panel shows more and more of the dark dunes as the overlying layer of seasonal ice evaporates back into the atmosphere.

The location in this series of images is at 80 degrees north latitude, 122.5 degrees east longitude.

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

Note: For more information, see Thawing 'Dry Ice' Drives Groovy Action on Mars.

Thursday, January 24, 2013

Mega Gully Near Echus Chasma

The mega gully in this VIS image empties into Echus Chasma.

Orbit Number: 48563 Latitude: 0.572332 Longitude: 278.937 Instrument: VIS Captured: 2012-11-24 19:58

Photo credit: NASA/JPL/Arizona State University

Wednesday, January 23, 2013

Channels and Fractures at Claritas Fossae

This VIS image of the Claritas Fossae region illustrates how fractures affect other features. In this instance, the fractures control the path of several channels (from upper right towards lower left). The channels follow the fractures and then follow the slope towards the bottom of the image.

Orbit Number: 48552 Latitude: -41.4612 Longitude: 258.678 Instrument: VIS Captured: 2012-11-23 20:30

Photo credit: NASA/JPL/Arizona State University

Matijevic Hill

As NASA's Mars Exploration Rover Opportunity neared the ninth anniversary of its landing on Mars, the rover was working in the 'Matijevic Hill' area seen in this view from Opportunity's panoramic camera (Pancam). Opportunity landed January 24, 2004, PST (January 25 UTC). The landing site was about 12 miles (19 kilometers), straight-line distance, or about 22 miles (35.5 kilometers) driving-route distance, from this location on the western rim of Endeavour Crater.

Matijevic Hill is an area within the "Cape York" segment of Endeavour's rim where clay minerals have been detected from orbit. This view is centered northwestward, toward the crest of Cape York. It extends more than 210 degrees from left to right. The field of view encompasses most of the terrain traversed by Opportunity during a "walkabout" in October and November 2012 to scout which features to spend time examining more intensely. Two of the features investigated at Matijevic Hill are "Copper Cliff," the dark outcrop in the left center of the image, and "Whitewater Lake," the bright outcrop on the far right.

Opportunity's Pancam took the component images for this mosaic during the period from the mission's 3,137th Martian day, or sol, (November 19, 2012) through Sol 3150 (December 3, 2012).

The image combines exposures taken through Pancam filters centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). The view is presented in approximate true color. This "natural color" is the rover team's best estimate of what the scene would look like if humans were there and able to see it with their own eyes.

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

Note: For more information, see PIA16703: 'Matijevic Hill' Panorama for Rover's Ninth Anniversary (for the full-size natural color image), PIA16704: 'Matijevic Hill' Panorama for Rover's Ninth Anniversary (False Color) , PIA16709: 'Matijevic Hill' Panorama for Rover's Ninth Anniversary (Stereo) , and NASA's Veteran Mars Rover Ready to Start 10th Year.

Tuesday, January 22, 2013

Dittaino Valles

Today's VIS image shows a portion of Dittaino Valles.

Orbit Number: 48551 Latitude: -1.07402 Longitude: 293.526 Instrument: VIS Captured: 2012-11-23 18:18

Photo credit: NASA/JPL/Arizona State University

Monday, January 21, 2013

Carbonate Layering in McLaughlin Crater

This view of layered rocks on the floor of McLaughlin Crater shows sedimentary rocks that contain spectroscopic evidence for minerals formed through interaction with water. The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter recorded the image.

A combination of clues suggests this 1.4-mile-deep (2.2-kilometer-deep) crater once held a lake fed by groundwater. Part of the evidence is identification of clay and carbonate minerals within layers visible near the center of this image. The mineral identifications come from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), also on the Mars Reconnaissance Orbiter.

The scene covers an area about one-third of a mile (about 550 meters) across, at 337.6 degrees east longitude, 21.9 degrees north latitude. North is up. Figure 1 [the second, annotated image above] indicates the location of layers bearing clay and carbonate minerals and includes a scale bar of 100 meters (328 feet).

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

Notes: For more information, see Layers with Carbonate Content Inside McLaughlin Crater on Mars. Unfortunately, these images are very low resolution, especially when compared to the very high resolution, very beautiful images the HiRISE team normally provides; however, this is the highest resolution NASA is releasing at this time.

Sunday, January 20, 2013

Dunes in a Noachis Terra Crater

Sand dunes on Mars are studied for many reasons. Recent investigations have focused on dune and ripples movement.

In this observation, we look at dunes within a crater in Noachis Terra. Zooming in to one of these areas (and here is the context image) we see the edges of two dunes separated by a field of ripples and rocks. We can compare this area to another image taken two Mars years ago. In the older image, there are many dark wispy features that cover the dunes. These are dust devil tracks, which formed when vortices removed a thin layer of dust off the surface, revealing a darker substrate.

In addition, there are dark sand streaks extending westward from the eastern dune. Blinking between these images shows that virtually all traces of the dust devil tracks and dark streaks have disappeared in the two Mars years. There is also little evidence for dune or ripple movement (however, these images have not yet been orthorectified for a detailed analysis).

In this region, it is likely that dust is periodically deposited and then removed off the dunes. The presence of dust may shield the dunes and ripples from significant movement, such that the observed changes are but thin layers of dust being removed and minor sand streaks that blow off the dunes.

This is a stereo pair with ESP_030080_1245.

Photo credit: NASA/JPL/University of Arizona

Note: The "blink" images, mentioned above, are well worth looking at. Here is the gif file below:

Saturday, January 19, 2013

Surface Textures at Planum Australe

Many different surface textures are found on the polar caps. This VIS images shows part of the surface of the south polar cap.

Orbit Number: 48511 Latitude: -86.8588 Longitude: 274.799 Instrument: VIS Captured: 2012-11-20 11:47

Photo credit: NASA/JPL/Arizona State University

John Klein Section of Gale Crater

This view shows the patch of veined, flat-lying rock selected as the first drilling site for NASA's Mars rover Curiosity. The rover's right Mast Camera (Mastcam), equipped with a telephoto lens, was about 16 feet (5 meters) away from the site when it recorded this mosaic's component images, between 3:10 and 3:33 in the afternoon of the 153rd Martian day, or sol, of Curiosity's work on Mars (January 10, 2013).

The area is shot full of fractures and veins, with the intervening rock also containing concretions, which are small spherical concentrations of minerals.The scale bar on the left image is 19.7 inches (50 centimeters) long. On the annotated version, three boxes, each about 4 inches (10 centimeters) across, designate enlargements on the right that illustrate attributes of the area.

Enlargement A shows a high concentration of ridge-like veins protruding above the surface. Some of the veins have two walls and an eroded interior. Enlargement B shows that in some portions of this feature, there is a horizontal discontinuity a few centimeters or inches beneath the surface. The discontinuity may be a bed, a fracture, or potentially a horizontal vein. Enlargement C shows a hole developed in the sand that overlies a fracture, implying infiltration of sand down into the fracture system.

The image has been white-balanced to show what the rocks would look like if they were on Earth.

Photo credit: NASA/JPL-Caltech/MSSS

Note: For more information, see PIA16568: Diversity in Vicinity of Curiosity's First Drilling Target and PIA16702: Neighborhood for Curiosity's First Drilling Campaign. Also, NASA Mars Rover Preparing to Drill Into First Martian Rock.

Channel and Crater Northeast of Hecates Tholus

The origins of channels on Mars is of great interest to understand the history of water.

There are several large (more than 30 kilometers wide) craters on Mars that appear to have spawned channels, perhaps draining from the fresh, hot impact ejecta.

Visible here is a well-preserved (meaning geologically young) crater that is about 3 kilometers wide, and a channel that appears from the margins of the ejecta and flows to the south. Did this small crater generate this relatively large channel?

Most likely the channel was there first, and the crater is younger. However, the channel might have been generated by a larger crater to the northwest.

Photo credit: NASA/JPL/University of Arizona

Note: This image is located west of Phlegra Montes and northeast of Hecates Tholus.

Friday, January 18, 2013

Ice Layering Near Chasma Australe

Today's VIS image shows the multitude of layers making up the South Polar cap.

Orbit Number: 48506 Latitude: -85.8144 Longitude: 95.4964 Instrument: VIS Captured: 2012-11-20 01:53

Photo credit: NASA/JPL/Arizona State University

Mineral Veins at the Sheepbed Unit

This image of an outcrop at the "Sheepbed" locality, taken by NASA's Curiosity Mars rover with its right Mast Camera (Mastcam), shows well-defined veins filled with whitish minerals, interpreted as calcium sulfate.

These veins form when water circulates through fractures, depositing minerals along the sides of the fracture, to form a vein.These veins are Curiosity's first look at minerals that formed within water that percolated within a subsurface environment. These vein fills are characteristic of the stratigraphically lowest unit in the "Yellowknife Bay" area -- known as the Sheepbed Unit.

Mastcam obtained these images the 126th Martian day, or sol, of Curiosity's mission on Mars (December 13, 2012). The view covers an area about 16 inches (40 centimeters) across.A superimposed scale bar is 8 centimeters (3.15 inch) long.

The image has been white-balanced to show what the rock would look like if it were on Earth.

Photo credit: NASA/JPL-Caltech/MSSS

Note: For more information, see PIA16615: Calcium-Rich Veins in Martian Rocks, PIA16616: Signs of Hydrated Calcium Sulfates in Martian Rocks, and PIA16617: Veins in Rocks on Mars and Earth.

Seasonal Erosion near Chasma Australe

Bright carbon dioxide frost (or, dry ice) highlights this network of channels carved into the surface. The channels are eroded a little bit every spring when the seasonal polar cap, composed of dry ice, sublimates (meaning going directly from a solid to gas) at the ice-surface interface. The erosion occurs under the seasonal ice layer: when trapped pressurized gas finds an escape route it carries along loose surface material. This surface material is blown downwind and deposited in dark fans on top of the seasonal ice layer.

The trapped gas finds the weakest easiest escape route. In this area the gas exploited the existing polygonal structure of the surface below. Polygonal terrain is common at high latitudes, and is caused by the thermal contraction and expansion of water ice frozen in the surface dirt.

Photo credit: NASA/JPL/University of Arizona

Note: This image is located near the western edge of Chasma Australe.

Thursday, January 17, 2013

Lava Flows in Daedalia Planum

The lava flows in today's VIS image are located on the northeastern margin of Daedalia Planum. Wind deposits are visible in the lee of the flow fronts.

Orbit Number: 48491 Latitude: -2.75786 Longitude: 223.234 Instrument: VIS Captured: 2012-11-18 19:48

Photo credit: NASA/JPL/Arizona State University

Spherules in Yellowknife Bay

This image from the right Mast Camera (Mastcam) of NASA's Curiosity Mars rover shows roughly spherical features. These are called spherules, and they are common in this stratigraphic unit, the Sheepbed Unit, which defines the lower part of the sequences of strata exposed in "Yellowknife Bay." These features are interpreted as concretions, implying they formed in water that percolated through pores in the sediment. Spherical concretions have previously been discovered in other rocks on Mars.

Mastcam obtained these images on the 139th Martian day, or sol, of Curiosity's surface operations (December 25, 2012). The image has been white-balanced to show what the rock would look like if it were on Earth.

Photo credit: NASA/JPL-Caltech/MSSS

Curiosity's Tracks in Gale Crater

This image was acquired for color coverage of the region that the Curiosity rover may explore, but we acquired some extra RED (monochromatic) coverage of the rover tracks.

This image shows the entire distance traveled from the landing site (dark smudge at left) to its location as of 2 January 2013 (the rover is bright feature at right). The tracks are not seen where the rover has recently driven over the lighter-toned surface, which may be more indurated than the darker soil.

Photo credit: NASA/JPL/University of Arizona

Wednesday, January 16, 2013

Shaler Outcrop

This image from the Mast Camera (Mastcam) on NASA's Mars rover Curiosity shows inclined layering known as cross-bedding in an outcrop called "Shaler" on a scale of a few tenths of meters, or decimeters (1 decimeter is nearly 4 inches). The superimposed scale bar is 50 centimeters (19.7 inches).

This stratigraphic unit is called the Shaler Unit. Decimeter-scale cross-bedding in the Shaler Unit is indicative of sediment transport in stream flows. Currents mold the sediments into small underwater dunes that migrate downstream. When exposed in cross-section, evidence of this migration is preserved as strata that are steeply inclined relative to the horizontal -- thus the term "cross-bedding." The grain sizes here are coarse enough to exclude wind transport. This cross-bedding occurs stratigraphically above the Gillespie Unit in the "Yellowknife Bay" area of Mars' Gale Crater, and is therefore geologically younger.

Mastcam obtained the image on the 120th Martian day, or sol, of Curiosity's surface operations (December 7, 2012).

The image has been white-balanced to show what the rock would look like if it were on Earth.

Photo credit: NASA/JPL-Caltech/MSSS

Note: For more information, see PIA16700: Wide View of 'Shaler' Outcrop, Sol 120.

Tuesday, January 15, 2013

Yellowknife Bay Veins and Concretions

The right Mast Camera (Mastcam) of NASA's Curiosity Mars rover provided this view of the lower stratigraphy at "Yellowknife Bay" inside Gale Crater on Mars. The rectangle superimposed on the left image shows the location of the enlarged portion on the right. In the right image, white arrows point to veins (including some under the overhang), and black arrows point to concretions (small spherical concentrations of minerals). Both veins and concretions strongly suggest precipitation of minerals from water.

The scale bar in the left image is 50 centimeters (19.7 inches) long. The scale bar in the right image is 10 centimeters (3.9 inches) long.

Mastcam recorded this view in the morning of the 137th Martian day, or sol, of Curiosity's surface operations (December 24, 2012). The image has been white-balanced to show what the rocks would look like if they were on Earth.

Photo credit: NASA/JPL-Caltech/MSSS

Note: For more information, see PIA16701: View from Inside 'Yellowknife Bay'.

Saturday, January 12, 2013

Overflow Channel from Athabasca Vallis

A MOC image over this area showed a channel spilling out of the larger Athabasca Vallis (trending east-west at the north end of this image) and flowing to the south.

The channel splits into multiple branches, creating about ten streamlined mesas. Vague bumps were visible on the channel floor in the MOC image--perhaps large boulders that were deposited by floodwaters?

Our HiRISE image reveals the bumps to be rootless cones that form from lava-water interaction. The entire channel system appears to be coated by lava. There are two leading hypotheses for the origin of these channels: (1) they were carved by water and later coated by lava, or (2) the channels were eroded by the lava itself. If eroded by lava, a source of water was still needed to create the rootless cones, but could have been a much smaller quantity of water than that needed to carve the channels.

(The MOC image can be viewed here, but note that it needs to be flipped left-right to correct the geometry.)

Photo credit: NASA/JPL/University of Arizona

Friday, January 11, 2013

Climbing Dunes in Nereidum Montes

This image shows the southern part of a dune field in Nereidum Montes, which is being monitored for changes in dune and ripple positions.

Many of the dunes in this image are overlying steep slopes. The slopes are dipping to the south, yet the dunes, as evidenced by the north-facing orientation of their steep slip faces, are being blown upslope, to the north. Such "climbing dunes" have been found elsewhere on Mars, such as in Valles Marineris and in this case, indicate relatively strong southerly winds.

A close-up image shows one of these slip faces. In addition, several apparent landslide troughs are present. These are interpreted as sand that has slumped down the slope. Subsequently, the wind has remobilized some of the sand and formed climbing ripples within the troughs. This and other HiRISE images show the dynamic interplay between wind and gravity, two of many processes occurring on Mars today.

(Note: view an unannotated version of the subimage with scale bar.)

Photo credit: NASA/JPL/University of Arizona

Saturday, January 5, 2013

Snake River Rock

The sinuous rock feature in the lower center of this mosaic of images recorded by the NASA Mars rover Curiosity is called "Snake River." The images in the mosaic were taken by Curiosity's Navigation Camera during the 133rd Martian day, or sol, of the rover's mission on Mars (December 20, 2012).

On Sol 147 (January 3, 2013), Curiosity drove about 10 feet (3 meters) to get a closer look at Snake River for before proceeding to other nearby rocks.

Photo credit: NASA/JPL-Caltech