Friday, July 25, 2014

Layering in Utopia Planitia

Today's VIS image shows layering in the plains that comprise Utopia Planitia.

Orbit Number: 54875 Latitude: 38.2154 Longitude: 112.575 Instrument: VIS Captured: 2014-04-28 05:54

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

Thursday, July 24, 2014

Lyot Crater Dunes

The dunes in this VIS image are located on the floor of Lyot Crater.

Orbit Number: 54853 Latitude: 50.2638 Longitude: 29.1544 Instrument: VIS Captured: 2014-04-26 10:23

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

Wednesday, July 23, 2014

Coloe Fossae

The channels in this VIS image are part of Coloe Fossae, a series of linear depressions on the northeast margin of Terra Sabaea.

Orbit Number: 54852 Latitude: 39.1441 Longitude: 55.8792 Instrument: VIS Captured: 2014-04-26 08:28

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

Tuesday, July 22, 2014

Hills and Dunes in Olympia Undae

This VIS image shows part of the large dune field called Olympia Undae. There are hills in this region, and the dunes are concentrated in the lower elevations.

Orbit Number: 54834 Latitude: 79.539 Longitude: 233.335 Instrument: VIS Captured: 2014-04-24 20:41

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

Sunday, July 20, 2014

Surface of Planum Boreum

At Mars’ North Pole is a dome of icy layers ranging up to 2 kilometers thick, roughly analogous to the Earth’s ice caps in Greenland or Antarctica.

Although not visible here, the dome is characterized by incised spiraling troughs that reveal sequences of layers thought to reflect varying climate conditions over the time they were originally deposited. This image is of an area on the top surface of the polar dome between the troughs — vast, generally smooth, flat plains composed of a thin layer of very pure water ice. This image also shows that this thin ice layer has a rough texture, composed of knobs, ridges, and depressions on the scale of 1 - 10 meters.

This texture is only beginning to be studied with the high-resolution capabilities of HiRISE — the details of the texture varies around the polar cap, but the causes of the variation are not yet clear. This image has two particularly interesting features. One is that the surface dips into a depression towards the southwest, where the texture of the ice surface appears to change. The other is that there is a fracture or chain of pits in the southeast, which is a rare feature.

The brightness, composition, texture, and small-scale features of this ice layer that covers most of the polar dome are important as they influence the local energy balance (such the amount of sunlight reflected and absorbed), which in turn influences polar-wide climate and the stability of ice.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18624: The Icy Surface of the North Polar Cap.

Saturday, July 19, 2014

Lonar Crater

Today's VIS image shows Lonar Crater. This crater has undergone very little modification since it formed, and so is one of the younger features in this region.

Orbit Number: 54828 Latitude: 72.999 Longitude: 38.4817 Instrument: VIS Captured: 2014-04-24 08:53

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

Note: Lonar Crater is located in Vastitas Borealis.

Crater Lake Sediments in Arabia Terra

This image shows some interesting fractured materials on the floor of an impact crater in Arabia Terra.

There is a channel entering the crater and exiting it (see CTX image). This channel, along with an unusual deposit on the lowest part of the floor, suggests that there was once an ancient lake that deposited sediments here.

Our enhanced-color sample shows layered deposits, some with polygonal patterns, as might be expected from lake sediments. The fracturing of these deposits might have resulted from the sudden breaching of the crater rim, draining the lake.

This is a stereo pair with ESP_035843_2165.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18625: Ancient Lake Sediments in a Crater.

Friday, July 18, 2014

Dunes in Olympia Undae

Today's VIS image is part of Olympia Undae. Compare this to previous images and notice how uniform the dunes are in this region.

Orbit Number: 54827 Latitude: 81.1656 Longitude: 217.246 Instrument: VIS Captured: 2014-04-24 06:46

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

Ridges in Eridania Basin

Eridania Basin, located at the head of Maadim Vallis, has mounting geomorphic and spectral evidence that it may have been the site of an ancient inland sea.

This site presents interesting mineralogical and geological evidence for the past existence of a large aqueous system on Mars that could have been long lived, and may have been well suited for ancient life, and almost certainly contains important clues about the ancient climate.

In this HiRISE image, there are numerous dark ridges against a brighter substrate. These ridges could be cemented and topographically inverted fractures, although other origins (such as eskers, channels, or volcanic dikes) cannot be ruled out. One way to produce these ridges would be when fluids moved through the fractures, causing cementation and hardening. Later, erosion removed the softer rocks surrounding the fractures, while the more resistant cemented materials within the fractures were left standing higher, thus appearing inverted.

Image credit: NASA/JPL/University of Arizona

Note: For more information, see PIA18623: Ridges in Eridania Basin.

Thursday, July 17, 2014

Dunes in Olympia Undae

The dunes in this VIS image are part of Olympia Undae, a huge dune field near the north polar cap.

Orbit Number: 54817 Latitude: 80.5695 Longitude: 147.52 Instrument: VIS Captured: 2014-04-23 11:00

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

Sparks from Nova

NASA's Curiosity Mars rover used the Mars Hand Lens Imager (MAHLI) camera on its arm to catch the first images of sparks produced by the rover's laser being shot at a rock on Mars. The left image is from before the laser zapped this rock, called "Nova." The bright spot at the center of the right image is the spark. The rock is about the size of a baseball.

The laser is fired by Curiosity's Chemistry and Camera (ChemCam) instrument. ChemCam also includes spectrometers to examine intensities of light at different wavelengths in sparks that the laser shots induce at the target. The spectrometer data inform researchers about which chemical elements are in the target.

In the first two years since Curiosity landed in Mars' Gale Crater in August 2012, ChemCam has used its laser on more than 600 rock or soil targets, firing more than 150,000 laser shots. The examination of the target rock Nova was the first during which MAHLI took images of the sparks generated by the laser shots. ChemCam fired 100 laser shots at Nova during the 687th Martian day, or sol, of Curiosity's work on Mars (July 12, 2014). MAHLI, snapping exposures at nearly five times per second during this series of laser shots, captured several of the resulting sparks, including the one in the image on the right. A video made from the series of MAHLI images is online at

ChemCam found Nova to be rich in silicon, aluminum and sodium. An image of the target from ChemCam's Remote Micro-Imager is PIA18388, along with a sampling of spectrometer data from the examination.

Image credit: NASA/JPL-Caltech/MSSS

Note: For more information, see PIA18388: Curiosity's ChemCam Examines Mars Rock Target 'Nova', PIA18396: Martian Rock and Dust Filling Studied with Laser and Camera, and NASA Rover's Images Show Laser Flash on Martian Rock.

Wednesday, July 16, 2014

Hills in Arabia Terra

The group of hills in this VIS image are located on the floor of a large unnamed depression in northern Arabia Terra.

Orbit Number: 54816 Latitude: 36.2303 Longitude: 13.2263 Instrument: VIS Captured: 2014-04-23 09:02

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

Lebanon Iron Meteorite

This rock encountered by NASA's Curiosity Mars rover is an iron meteorite called "Lebanon," similar in shape and luster to iron meteorites found on Mars by the previous generation of rovers, Spirit and Opportunity. Lebanon is about 2 yards or 2 meters wide (left to right, from this angle). The smaller piece in the foreground is called "Lebanon B."

This view combines a series of high-resolution circular images taken by the Remote Micro-Imager (RMI) of Curiosity's Chemistry and Camera (ChemCam) instrument with color and context from rover's Mast Camera (Mastcam). The component images were taken during the 640th Martian day, or sol, of Curiosity's work on Mars (May 25, 2014).

The imaging shows angular shaped cavities on the surface of the rock. One possible explanation is that they resulted from preferential erosion along crystalline boundaries within the metal of the rock. Another possibility is that these cavities once contained olivine crystals, which can be found in a rare type of stony-iron meteorites called pallasites, thought to have been formed near the core-mantle boundary within an asteroid.

Iron meteorites are not rare among meteorites found on Earth, but they are less common than stony meteorites. On Mars, iron meteorites dominate the small number of meteorites that have been found. Part of the explanation could come from the resistance of iron meteorites to erosion processes on Mars.


Tuesday, July 15, 2014

Aspledon Undae

This VIS image shows part of Aspledon Undae, a region of dunes near the north pole. The right side of the image shows hundreds of small, isolated dunes. On the left side of the image, these small dunes appear to have merged into larger dune forms.

Orbit Number: 54806 Latitude: 72.1234 Longitude: 312.147 Instrument: VIS Captured: 2014-04-22 13:26

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