Tag: Mars Reconnaissance Orbiter

Data from Opportunity suggests surface dew periodically appears even in the dry equatorial regions

4:43 pm

Using data from the rover Opportunity, scientists now think that the renewal of Martian salt crusts on rock surfaces on the rim of Endeavour Crater could possibly by caused by the appearance of rare thin wetting events, and that such events could have even occurred very recently and be on-going..

The scientists looked at the rate of erosion and renewal of the salt crusts, and found them to be in a steady state. The erosion is slow, taking from 200,000 to 2,000,000 years to remove 1 to 2 millimeters. However, periodically a thin film of water or wetting occurs, not unlike dew on Earth, which quickly acts to renew the crust. As David Mittlefehldt of the Astromaterials Research Office at the Johnson Space Center and the lead author of the paper explained to me,

Taken together, the data leaves open the possibility the salt mobilization has occurred within the last few thousand years. It could be ongoing in the sense that over a period of thousands? or hundreds? of years it might happen again.

In other words, the evidence suggests that every few hundred or thousand years the surface of these rocks gets wet, which results in the placement of a new thin layer of salt crusts.

Mittlefehldt also emphasized to me that these wetting events are rare, and “there is also the case that such an event may never come again because of changing conditions.”

The situation is essentially like on Earth, where in some places hydrologists measure the size of floods by how rare they are. A 1,000 year flood is big, but it happens very rarely. At Endeavour Crater these wetting events are comparably rare, but they do not involve big floods, but a mere moistening of the ground.

The location of Endeavour Crater is about 2 degrees south latitude, so it sits in the dry equatorial regions where no surface or near surface ice has so far been found. However, the cyclic nature of Mars’ orbit and obliquity could have changed this in the past, and could change this again in the future. At this time we simply don’t have enough information to know.

0 comments

On the edge of Mars’ glacier country

1:25 pm

Color dry mesas on Mars
Click for full image.

Today’s cool image sits right on the southern edge of Mars’ northern glacier country, at 29 degrees north latitude. The picture to the right, cropped and reduced to post here, was taken of this location on June 4, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what appears to be the exposed and scraped bedrock and mesas on the floor of an unnamed 60-mile-wide crater.

That scraped bedrock is quite beautiful, reminiscent of the bare carved mesas and bedrock one sees throughout the southwest of the United States. To hike from that central valley to the top of the bright mesa would be a fine experience, especially because of the suggested change in colors in the color strip.

The overview map below gives more context.
» Read more

0 comments

Glaciers and mesas on Mars

2:19 pm

Overview map

Cool image time! Today we return to glacier country on Mars, that band of mensae mesas and glaciers that stretches more than 2,000 miles in the northern mid-latitudes, as shown on the overview map above.

No rovers or landers have yet visited this region, nor are any planned. To the west just beyond the map’s left edge is the planned landing site of Europe’s Franklin rover. To the east and south and just beyond the map’s right edge is where America’s Perseverance rover presently travels in Jezero Crater.

Our journey today begins from afar, and will steadily zoom into the area of the red cross and a most intriguing feature seen in a recent picture taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

Before we look at that high resolution image, it is better to view the area using MRO’s context camera, as what it shows helps make sense of the features in the close-up.
» Read more

4 comments

Perseverance’s 2nd drill attempt to get sample appears successful

11:18 am

It appears that Perseverance’s second drill attempt on Mars has successfully obtained sample material in its core.

Data received late Sept. 1 from NASA’s Perseverance rover indicate the team has achieved its goal of successfully coring a Mars rock. The initial images downlinked after the historic event show an intact sample present in the tube after coring. However, additional images taken after the arm completed sample acquisition were inconclusive due to poor sunlight conditions. Another round of images with better lighting will be taken before the sample processing continues.

Once they know for sure if they have a sample, they will store it and then move on, heading to the area that Ingenuity scouted for them in mid-August.

Posted halfway to Las Vegas.

4 comments

A peanut-shaped crater in the northern plains of Mars

1:21 pm

Context camera image of peanut-shaped crater
Click for full image.

Cool image time! The photo to the right, rotated, cropped and reduced to post here, was taken in May 2008 by the wide angle context camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists have since labeled a “peanut-shaped crater.”

What caused this unusual shape? The obvious and most likely explanation is that this was a double impact that occurred simultaneously. Imagine the ground being hit either by an asteroid with two lobes or by two similar-sized asteroids falling side-by-side.

Fast forward thirteen years to 2021. In the fifteen years since 2006 when MRO begin science operations in orbit around Mars no high resolution images were taken of this crater. Finally, on July 30, 2021, scientists finally decided to take a high resolution image of this crater’s western half. You can see that image below, rotated, cropped, and reduced to post here.
» Read more

3 comments

Stucco on Mars!

12:33 pm

Stucco on Mars
Click for full image.

Cool image time! The picture to the right, cropped to post here, was taken on June 8, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a strangely flat plain with a complex stucco-type surface of ridges and depressions. The sunlight is coming from the west, which makes the smoother flat areas depressions.

What are we looking at? What causes this strange surface? Make sure you look at the full image, because the section I cropped out doesn’t give a true sense of the terrain’s vastness.

The MRO science team labeled the photo “volcanic terrain,” but that tells only part of the story, since this volcanic terrain is actually part of Mars’ most interesting lava plains, as the overview map below shows.
» Read more

2 comments

An ancient curving channel on Mars

10:30 am

Context image of curving channels
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken by the wide angle context camera on Mars Reconnaissance Orbiter (MRO) in April 2019. It shows an area on Mars where a number of meandering curving channels flow downhill from the west to the east.

Earlier MRO images had already spotted these channels, so when this context image was taken the scientists also took a high resolution image of the same channels, with the white box indicating the area covered by the rotated, cropped, and reduced image below.

Both images are today’s MRO image of the day, where the MRO team notes that “The objective of this observation is to examine a complex network of channels. Some parts of the channels are quite curved.”
» Read more

1 comment

New cracks across old Martian lava flows

1:03 pm

New cracks across an old lava flow
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on June 4, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It captures one of the many deep straight fissure canyons that make up the feature dubbed Cerberus Fossae in the center of Mars’ volcano country.

The crack is called a graben, and happens when the ground is either stretched from pressure from below, or when two adjacent large blocks of material move sideways relative to each other.

What makes this particular graben interesting are two features. First, the overlapping break suggests something complex took place at this spot when the crack separated. Second, the crack cut across the foot of an older frozen lava flow, meaning it has to be younger than that flow.

The overview map below provides a clue when that lava flow might have occurred, while also suggesting this crack in Cerberus Fossae might be much younger than expected.
» Read more

6 comments

A weak avalanche season on Mars?

1:39 pm

The north pole scarp
Click for full image.

Today’s cool image from Mars is cool both for what is visible in the photo and for what is not, the latter of which might turn out to be a discovery of importance.

The photo to the right, cropped and reduced to post here, was taken on June 24, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a section of the edge of Mars’ north polar ice cap, with north at the top.

This scarp is probably more than 2,000 feet high, though that height drops to the south as the upper layers disappear one by one from either long term erosion or sublimation. Those layers represent the visible information in the photo that is cool. They give us tantalizing clues about the geological and climatic history of Mars. Each layer probably represents a climate period when the north icecap was growing because the tilt of the planet’s rotation was even less than the 25 degrees it is now. When that tilt is small, as small as 11 degrees, the poles of Mars are very cold, and water ice migrates from the mid-latitudes to the poles, adding thickness to the icecaps. When the tilt grows, to as much as 55 degrees, the mid-latitudes are colder than the poles, and the water ice migrates back to the mid-latitudes.

What is not visible in this picture, however, might be far more significant.
» Read more

0 comments

A dry bedrock Martian crater floor?

1:01 pm

A dry bedrock crater floor?
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on June 21, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The location is a very eroded crater at about 26 degrees north latitude. The image shows the crater’s crater floor, with a variety of bedrock-type features, sharp ridges, abrupt scarps, and flat smooth plateaus, with a hint of lobate glacial flows in the image’s southeast quadrant.

At 26 north latitude, it is unlikely that anything here is icy, unless it is very well protected by debris. Most of these features are almost certainly bedrock, though their formation could very well have been shaped by ice in past eons when this location was more amenable to water ice.

The wider MRO context camera image of the entire crater, plus the overview map, give a larger picture, and raise some interesting questions.
» Read more

2 comments

Lacy patterns in the high north of Mars

12:27 pm

lacy patterns in the high north of Mars

Cool image time! The photo to the right, cropped, reduced, and rotated so that north is up, was taken on May 12, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the strange lacy patterns seen routinely in the very high northern latitudes surrounding the Martian north pole.

Located in a region of the vast northern lowland plains dubbed Scandia Tholi, such features are apparently common here. From a 2011 geology paper of the region’s geological history:

We find that Scandia Tholi display concentric ridges, rugged peaks, irregular depressions, and moats that suggest uplift and tilting of layered plains material by diapirs and extrusion, erosion, and deflation of viscous, sedimentary slurries as previously suggested. These appear to be long-lived features that both pre-date and post-date impact craters.

The small circular feature near the bottom of the picture appears to be a mesa, and might be a pedestal crater, so old that the surrounding terrain has worn away and left the hardened-by-impact crater as a butte. To its right is a larger circular mesa with its scarp well eroded into hollows. This might also be a pedestal crater, or not.

The white lacy patterns could be frost, either water ice or dry ice. That the white lace tends to favor the north-facing slopes lends support to this guess. The photo was taken in the early spring, so the thin mantle of carbon dioxide that falls to cover the polar region south to sixty degrees latitude is only beginning to sublimate away.

0 comments

A Martian river of ice

12:59 pm

Glacial flow on Mars?
Click for full image.

Cool image time! The photo to the right, rotated, cropped and reduced to post here, was taken on May 13, 2021 by the high resolution camea on Mars Reconnaissance Orbiter (MRO). It spans the entire 4.7 mile width of the southern hemisphere canyon dubbed Reull Vallis. The white arrow indicates the direction of the downhill grade

The scientists title this image “Lineated Valley Fill.” The vagueness of this title is because they have not yet confirmed that this lineated valley fill is a glacier flowing downhill to the west.

Nonetheless, the material filling this valley has all the features one expects glaciers to exhibit. Not only is the the lineation aligned with the flow, it varies across the width of the canyon as glaciers normally do. At the edge the parallel grooves are depressed, probably because they are torn apart by the canyon walls as the glacier flows past. In turn, at the center of the flow the grooves are thinner and more tightly packed, and appear less disturbed. Here, the flow is smooth, less bothered by surrounding features.

This pattern also suggests the merging of two flows somewhere upstream.

A glance at the spectacular Concordia glacier in the Himalayas near the world’s second highest mountain, K2, illustrates the similarity of this Martian feature to Earth glaciers.

Reull Vallis itself flows down to Hellas Basin, the deepest basin on Mars. As it meanders downhill along its 650 mile length it steadily gets wider and less distinct as it drops into Hellas. Along its entire length MRO has photographed numerous similar examples of this lineated fill, all suggesting that under a thin layer of debris is a thick glacier, slowerly carving this canyon out.

The overview map below illustrates these facts nicely, while further reinforcing these glacial conclusions.
» Read more

8 comments
1 … 52 53 54 55 56 … 90