HiRISE: A crater slope in Terra Sirenum mocks us

tumblr_ou47v0CMXm1rlz4gso1_1280A crater slope in Terra Sirenum mocks us. Beautiful Mars series.

Posted in Reports | Tagged , , , , , , , , , | Leave a comment

THEMIS: Basaltic dunes and frost in north polar lowlands

Bare ground, basaltic dunes, and frost (THEMIS_IOTD_20170919)THEMIS Image of the Day, September 19, 2017. Siton Undae is a large dune field located in the northern plains near Escorial Crater. Siton Undae is west of the crater and is one of three dune fields near the crater. The nearby north polar cap is dissected by Chasma Boreale, which exposes an ice free surface. This image was collected during the middle of northern hemisphere summer. There is no frost left on the dunes and they appear dark. These dunes are likely formed of basaltic sand.

NASA’s Mars Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69,000 times. It holds the record for longest working spacecraft at Mars. THEMIS, the IR/VIS camera system, has collected data for the entire mission and provides images covering all seasons and lighting conditions.

Over the years many features of interest have received repeated imaging, building up a suite of images covering the entire feature. From the deepest chasma to the tallest volcano, individual dunes inside craters and dune fields that encircle the north pole, channels carved by water and lava, and a variety of other feature, THEMIS has imaged them all.

For the next several months the Image of the Day will focus on the Tharsis volcanoes, the various chasmata of Valles Marineris, and the major dunes fields. We hope you enjoy these images!

More THEMIS Images of the Day by geological topic.

Posted in Reports | Tagged , , , , , , , , , , , , , , , , , | Leave a comment

HiRISE: A sequence of beauty in Terby Crater

ESP_013305_1515The north-facing wall of a moat-like depression in the middle of Terby Crater exposes a beautiful 400 meter-high sequence of light-toned, repetitive sedimentary layers. These deposits are often obscured by darker-toned patches of material as well as ripples and dunes.

The deposits in Terby, located on the northern rim of Hellas Planitia, are consistent with deposition in a standing body of water. The layers have been proposed as science targets for future landed missions. [More at link]

Posted in Reports | Tagged , , , , , , , , , | Leave a comment

Dust devils: major source of atmospheric dust on Mars and Earth

SONY DSCSwirling columns of sand and dust, known as dust devils, are a feature of desert areas on Mars and on Earth. Now, a study of terrestrial dust devils has shown that around two thirds of the fine particles lifted by these vortices can remain suspended in the atmosphere and be transported around the globe. The findings have implications for the climate and weather of both planets and, potentially, human health here on Earth. Results will be presented by Dr Jan Raack of the Open University at the European Planetary Science Congress (EPSC) 2017 in Riga, Latvia on Monday, 18th September 2017.

The study by Raack and an international team of collaborators gives important insights into the contribution of dust devils to mineral aerosols in planetary atmospheres. About half of the dust lifted into the martian atmosphere each year is thought to come from dust devils. However, to date, the structure of these vortices has not been well understood. As terrestrial dust devils act very similarly to those on Mars, Raack and colleagues have carried out multiple field campaigns over the past five years to study dust devils in three different deserts on Earth, in China, Morocco and the USA. The researchers took samples of grains lifted by dust devils at different heights, studied tracks left by dust devils on the surface and measured physical and meteorological properties of dust devils.

Raack explains: “The method for sampling is simple – although not actually that pleasant to carry out as it involves getting sandblasted. Essentially, we cover a 5-metre aluminium pipe with double sided sticky tape and run into an active dust devil. We hold the boom upright in the path of a dust devil and wait until the dust devil passes over the boom. Numerous grains are collected on the sticky tape, which are preserved on-site by pressing sections of the tape from different heights onto glass slides.” [More at links]

Posted in Reports | Tagged , , | Leave a comment

Opportunity: Perseverance Valley (very) close-up

4851-mi1F558840148EFFD0AKP1110R0M1Sol 4851, September 16, 2017. The Microscopic Imager shoots a target named Albuquerque on the ground in front of Opportunity. At right is the Hazcam view. Click either image to enlarge it.

Opportunity raw images, its latest mission status, location map, and atmospheric opacity, known as tau.

Posted in Reports | Tagged , , , , , , , | Leave a comment

HiRISE: Crevassed glacier-like forms

tumblr_ou47mvtsnk1rlz4gso1_1280Crevassed glacier-like forms. Beautiful Mars series.

Posted in Reports | Tagged , , , , , , , , , | Leave a comment

Inverted terrain shows ancient stream-flow details

1745-CardenasRiver deposits exist across the surface of Mars and record a surface environment from over 3.5 billion years ago that was able to support liquid water at the surface. A region of Mars named Aeolis Dorsa contains some of the most spectacular and densely packed river deposits seen on Mars. These deposits are observable with satellite images because they have undergone a process called “topographic inversion.” where the deposits filling once topographically low river channels have been exhumed in such a way that they now exist as ridges at the surface of the planet.

With the use of high-resolution images and topographic data from cameras on orbiting satellites, B.T. Cardenas and colleagues from the Jackson School of Geosciences identify fluvial deposit stacking patterns and changes in sedimentation styles controlled by a migratory coastline. They also develop a method to measure river paleo-transport direction for a subset of these ridges. [Their work was published in the GSA Bulletin.] (…)

Cardenas and colleagues conclude that similar falling and rising water levels in a large water body forced the formation of the paleo-valleys in their study area. Cross-cutting relationships are observed at the valley-scale, indicating multiple episodes of water level fall and rise, each well over 50 meters, a similar scale to eustatic sea level changes on Earth. [More at links]

Posted in Reports | Tagged , , , , , , | Leave a comment

THEMIS: Frosty dunes in Siton Undae

Frosty dunes in Siton Undae (THEMIS_IOTD_20170918)THEMIS Image of the Day, September 18, 2017. Siton Undae is a large dune field located in the northern plains near Escorial Crater. Siton Undae is west of the crater and is one of three dune fields near the crater. The nearby north polar cap is dissected by Chasma Boreale, which exposes an ice free surface. This image was collected during early spring in the northern hemisphere. The bright appearance of the dunes is due to frost cover. As the season progresses the dunes become darker as the frost disappears.

NASA’s Mars Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69,000 times. It holds the record for longest working spacecraft at Mars. THEMIS, the IR/VIS camera system, has collected data for the entire mission and provides images covering all seasons and lighting conditions.

Over the years many features of interest have received repeated imaging, building up a suite of images covering the entire feature. From the deepest chasma to the tallest volcano, individual dunes inside craters and dune fields that encircle the north pole, channels carved by water and lava, and a variety of other feature, THEMIS has imaged them all.

For the next several months the Image of the Day will focus on the Tharsis volcanoes, the various chasmata of Valles Marineris, and the major dunes fields. We hope you enjoy these images!

More THEMIS Images of the Day by geological topic.

Posted in Reports | Tagged , , , , , , , , , , , , , , , , , | Leave a comment

Curiosity update: Brushfest

NLB_558722525EDR_F0660084NCAM00256M_-br2Sol 1818-19, September 16, 2017, update by MSL scientist Ken Herkenhoff: We are planning only 2 sols today because there will be a soliday on Sunday to get us back in sync with “Mars time” in Gale Crater. The focus of science planning this morning was on observations of the current workspace, including an experiment to acquire APXS and MAHLI data on a bedrock target before and after brushing. MAHLI images of three potential DRT targets were received and used to determine which of these small exposures could be brushed. One had small pebbles in the DRT ellipse, so could not be brushed, but both of the other targets (“Christmas Cove” and “Mitten Ledge”) are brushable. So the APXS will measure the chemistry of Christmas Cove before it is brushed off, then will be… [More at link]

Posted in Reports | Tagged , , , , , , , , , , , , , | Leave a comment

Curiosity: MAHLI goes to work on the ridge-top

1814-mastcam-anno1816MH0007240010701382E01_DXXXSol 1816, September 15, 2017. With Curiosity parked on top of Vera Rubin Ridge, scientists are starting to examine rocks in its vicinity. Above is part of a Mastcam composite taken on Sol 1814; it enlarges when clicked. (More complete view here.)

1816MH0007240010701380E01_DXXXStars mark target locations selected for close-up images by the Mars Hand Lens Imager, or MAHLI, on Sol 1816. These are arrayed at right, with the left-most target at top.

1816MH0007240010701384E01_DXXXNote the fine-scale layering in the rocks as revealed by wind erosion. (The local time was about an hour later in the martian day than the Sol 1814 Mastcam images, so the lighting differs somewhat.)

Sol 1816 raw images (from all cameras), and Curiosity’s latest location.

Posted in Reports | Tagged , , , , , , , , | Leave a comment