HiRISE Captioned Images 2020

See new, spectacular, or mysterious sky images.
User avatar
bystander
Apathetic Retiree
Posts: 19392
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

HiRISE Captioned Images 2020

Post by bystander » Sat Jan 18, 2020 9:03 pm

Week of 13 Jan 2020
HiRISE Science Team wrote:
ESP_062714_2350[1].jpg

A First Look at a Gullied Slope (ESP_062714_2350)

HiRISE has been operating since 2006, and lately many of our observations of gullies are repeat images designed to study changes. However, we are also collecting data over gullies never before seen at this resolution, to study their morphology and allow us to look for changes in the future.

This is the first HiRISE look at a cluster of gullies that appear modified or degraded—the gully fans have ripples and ridges that have formed since the last major gully activity, suggesting that they don’t change very often, but we won’t know for sure unless we look!
Candy Hansen wrote:

Streamers of Frost (ESP_062556_1415)

When we acquired this image, it was northern summer and southern winter on Mars, but signs of spring are already starting to appear at latitudes not far from the equator. This image of Penticton Crater, taken at latitude 38 degrees south, shows streamers of seasonal carbon dioxide ice (dry ice) only remaining in places in the terrain that are still partially in the shade.

The turquoise-colored frost (enhanced color) is protected from the sun in shadowed dips in the ground while the sunlit surface nearby is already frost-free.
Candy Hansen wrote:

Dunes Frozen in Time (ESP_062562_1670)

Sand dunes are found in many places on Mars. At most of these places the dunes are slowly moving, blown by the wind, just like on Earth. However, in this location in south Melas Chasma they appear to have turned to stone.

The large dunes are slowly being eroded and disappearing, replaced by smaller structures of scalloped sand.
HiRISE Science Team wrote:

Barchan and Linear Dunes (ESP_062731_2645)

This image shows two types of sand dunes on Mars. The small dots are called barchan dunes, and from their shape we can tell that they are upwind. The downwind dunes are long and linear.

These two types of dunes each show the wind direction in different ways: the barchans have a steep slope and crescent-shaped “horns” that point downwind, while the linear dunes are stretched out along the primary wind direction. Linear dunes, however, typically indicate a wind regime with at least two different prevailing winds, which stretch out the sand along their average direction.

In several places in this image, you can find barchan dunes turning into linear dunes as they are stretched out, but they both seem into indicate the same wind direction.
Alfred McEwen wrote:
ESP_062793_2655[1].jpg

North Polar Changes over 6 Mars Years (ESP_062793_2655)

MRO has been observing Mars for 6 Mars Years (MY), each of which lasts for 687 Earth days. Shown here is an impact crater on the north polar ice cap, which contains an icy deposit on the crater floor.

These inter-crater ice deposits shrink and expand or change shape or surface texture from year to year, In this animation, we can see the appearance of this crater fill in MY 29 (2/2008), 30 (8/2010), 31 (7/2012), 33 (2/2016), 34 (1/2018), and 35 (12/2019).

Credit: NASA/JPL-Caltech/University of Arizona
You do not have the required permissions to view the files attached to this post.
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
bystander
Apathetic Retiree
Posts: 19392
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: HiRISE Captioned Images 2020

Post by bystander » Fri Jan 31, 2020 7:27 pm

Week of 20 Jan 2020
Alfred McEwen wrote:

Mounds Cut by a Fissure (ESP_062943_2230)

This image shows four relatively bright mounds along a linear, curving feature that appears to be a rift zone, where the shallow surface materials have pulled apart. The mounds also appear to be deformed.

A possible geologic interpretation is that as the rift began to open, subsurface material (perhaps mud) erupted to create the mounds, which were then deformed as the rift continued to spread. This region (Chryse Planitia) is a low-elevation basin in which large outflow channels deposited water and sediments billions of years ago.

This is a stereo pair with ESP_062877_2230.
Alfred McEwen wrote:

A Giant Gully in Kaiser Crater Dunes (ESP_062928_1325)

HiRISE has been monitoring this dune field since 2008, and it changes every year from gully erosion in the winter and blowing sand in the summer.

This cutout shows an especially large gully. The bright white materials are seasonal frost, persisting on shaded slopes.
Alfred McEwen wrote:

Dunes in Briault Crater (ESP_062912_1700)

Active sand dunes are common on Mars, and have a variety of surface textures. The “braided” texture visible here may be typical of dunes that are transitioning into sand sheets.

Also see this image for a Context Camera view of this area.

This is a stereo pair with ESP_060855_1700.
Alfred McEwen wrote:

Frosted Gullies (ESP_062894_1435)

Gullies on Mars form during the winter, fluidized by carbon dioxide frost, so we monitor these sites for activity throughout the year.

This mid-winter scene is almost completely frosted over the pole-facing slope within the shadow.
Alfred McEwen wrote:

Sandstone in West Candor Chasma (ESP_062839_1740)

Candor Chasma in central Valles Marineris is filled with light-toned layered deposits thought to be sandstones, perhaps formed in an ancient wet and potentially habitable environment.

The CRISM instrument on MRO has acquired thousands high-resolution spectral images across Mars, often with simultaneous coverage by HiRISE, but sometimes, for a variety of reasons, without HiRISE coverage. We are now trying to complete coordinated coverage over such locations, to enable geologic interpretations based on both the compositional information of CRISM and the high-resolution imaging of HiRISE.

Credit: NASA/JPL-Caltech/University of Arizona
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
bystander
Apathetic Retiree
Posts: 19392
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: HiRISE Captioned Images 2020

Post by bystander » Fri Jan 31, 2020 7:51 pm

Week of 27 Jan 2020
HiRISE wrote:

Dulovo Crater Region Barchan Dunes (ESP_055303_1835)

This image was a HiRISE Picture of the Day on 27 January 2020.
Alfred McEwen wrote:

Possible Landing Region for a Future Mars Sample Return (ESP_062886_1990)

Although the “Mars 2020” rover (to be renamed) is planned to land inside Jezero Crater, HiRISE continues to image the regions to the west of the crater because the rover may drive into this area in its extended mission.

If so, this western region may be a potential location to set down a future mission that might carry an ascent vehicle and a “fetch” rover. The enhanced color cutout highlights an interesting portion of this image, with fractured bedrock and wind-blown dunes.
Alfred McEwen wrote:

The Schiaparelli Crash Site (ESP_062731_1780)

The ExoMars Schiaparelli Lander (Entry, Descent, and landing Module, or EDM) crashed on the Martian surface on 19 October 2016. Also on that day the Trace Gas Orbiter successfully entered Mars orbit.

The HiRISE images acquired soon after the crash showed diffuse dark markings surrounding a shallow crater, plus small bright spots. HiRISE re-imaged this location on 25 March 2019, while dust was still settling from the planet-encircling dust storm, so surface features had low contrast.

HiRISE re-imaged this spot again through a much clearer atmosphere on 14 December 2019 (see animation). Much of the diffuse dark material has faded, perhaps from dust fallout, such that the crater is now more distinct. At least two bright spots are still visible.

In 2020 we expect three launches to Mars leading to landing attempts in early 2021: NASA’s unnamed (Mars 2020) rover, that will collect samples for return to Earth; the ESA/Roscosmos ExoMars lander and Rosalind Franklin rover; and an orbiter, lander, and Huoxing-1 (Mars-1) rover from China. HiRISE will be ready to see what happens.
Alfred McEwen wrote:

Watching the InSight Lander Region (ESP_062884_1845)

HiRISE periodically images the InSight lander region in case anything changes, such as the appearance of new dust devil tracks. InSight has detected many passing atmospheric vortices, but they do not necessarily disturb the surface sufficiently to create a new track visible from orbit.

The cutout (with the the lander in the upper left corner) was given a “hard” stretch, saturating the brightest and darkest regions, to better detect subtle dust devil tracks. There are several southeast-to-southwest trending streaks to the east of the lander that may be from dust devils, but they were also present in a prior HiRISE image acquired about one month earlier, so they did not form in the past month. The bright spot next to the lander is a specular reflection from the smooth hemispherical cover over the seismometer.
Alfred McEwen wrote:

North Polar Block Party (ESP_062866_2640)

The steep edge of the north polar cap is falling apart. This animation shows where a section of the slope at right has collapsed since 3 Mars years ago and deposited a field of ice blocks.

Credit: NASA/JPL-Caltech/University of Arizona
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor