Tag Archives: Mars Reconnaissance Orbiter

Status update on Mars Reconnaissance Orbiter

Link here. The story is focused on the decision by NASA to hold off launching a replacement for MRO and instead keep it operating for another decade. In telling this story, however, the article also provides us a detail look at the spacecraft’s present condition.

[A]ging batteries and gyroscopes, used to store electricity and aid navigation, will have to be carefully watched in the coming years to keep the mission going. “We found that they weren’t charging at full capacity,” Tamppari said of the batteries. MRO charges its batteries through its solar arrays while in sunlight. During night passes over Mars, the orbiter draws electricity from its batteries for about 40 minutes during each two-hour lap around the planet. The spacecraft now charges its batteries higher than before, NASA said, and engineers sent up commands for MRO to reduce the draw on the batteries while in shadow.

MRO’s two inertial measurement units are also showing signs of their age. Each redundant unit contains three gyroscopes and three accelerometers, feeding data about the spacecraft’s orientation to on-board computers. One measurement unit likely in the final months of its useful lifetime, Tamppari said, and the other is showing signs of degradation.

Ground controllers found a work-around by implementing an “all-stellar” navigation mode on MRO in March. The new technique allows the orbiter to sense the positions of the stars to determine which way it is pointing. “In all-stellar mode, we can do normal science and normal relay,” said Dan Johnston, MRO project manager at JPL, in a statement released in February. “The inertial measurement unit powers back on only when it’s needed, such as during safe mode, orbital trim maneuvers, or communications coverage during critical events around a Mars landing.”

There’s more at the link. Since MRO is also used as the main communications relay satellite between the Martian ground-based probes and the Earth, the story also outlines the communications capabilities of all spacecraft presently orbiting Mars. All told, it seems that if MRO fails the research on the surface will be significantly impacted, even if the rovers and landers are all still working.

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More weird Mars geology

Low resolution of full image of crater

Cool image time! Yesterday the Mars Reconnaissance Orbiter team released 460 images taken by the spacecraft’s high resolution camera, HiRISE, as part of their normal and routine image release program. Obsessed with space exploration as I am, I like to scan through these new images to see if there is anything interesting hidden there that will show up eventually in a press release. For example, the first image in this release is a look at Vera Rubin Ridge and Curiosity. I would not be surprised if there is a press release soon using this image, probably aimed at outlining the rover’s future route up Mount Sharp. (The present overview traverse map is getting out of date.)

Sometimes however I find images that might never get a press release but probably deserve it. The image on the right, reduced in resolution to show here, is one such example. It is a strip taken from rim to rim across an unnamed crater located in the mid-northern latitudes of Mars, west of Olympus Mons. A review of past images by other Mars orbiters/probes suggests that no good high resolution image of this crater had ever been taken before.

If you click on the image on the right, or go to the actual image site, you can see the original in full resolution. It is definitely worthwhile doing this, because the strip shows some strange and inexplicable geology on the floor of the crater as well in its confusing central peak region. Numerous features appear to have been exposed by later erosion. The many small craters for example are I think what planetary geologists call pedestal craters. The surrounding terrain is less erosion-resistant, so as that terrain erodes away it leaves the crater behind, with its floor actually sitting higher than the surrounding flats.

What makes these craters even weirder however is that their rims appear to have eroded away even more than the surrounding terrain, so that all of these small craters (assuming that is what they are) have ringlike depressions surrounding a circular platform.

In the crater’s central peak region the terrain is even more strange. Sticking up out of the ground are some arched short ridgelines, which appear to have been exposed by erosion. That peak area however also has many strange flow features that I find completely baffling. It almost appears to me that as the molten peak area started to solidify after impact, someone went in with a stirring spoon and did some mixing!

The map below the fold provides the location context for this crater, with the crater’s location indicated by the arrow.
» Read more

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Mars Reconnaissance Orbiter comes out of safe mode

On February 23 the Mars Reconnaissance Orbiter (MRO) engineering team was able to bring the spacecraft out of safe mode, after a low battery voltage reading caused it to shut down.

Mission team members brought MRO out of safe mode on Friday (Feb. 23), NASA officials said. The orbiter seems to be in good health overall; the battery voltage is back to normal, MRO is communicating with Earth, and temperatures and power levels are stable, agency officials said.

But MRO’s handlers haven’t put the orbiter back to work yet. “We’re in the diagnostic stage, to better understand the behavior of the batteries and ways to give ourselves more options for managing them in the future,” MRO project manager Dan Johnston, of NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement. “We will restore MRO’s service as a relay for other missions as soon as we can do so with confidence in spacecraft safety — likely in about one week. After that, we will resume science observations.”

Overall this sounds like very good news.

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Mars Reconnaissance Orbiter in safe mode

After detecting low battery voltage, Mars Reconnaissance Orbiter (MRO) went into safe mode on February 15.

The orbiter is solar-powered but relies on a pair of nickel-hydrogen batteries during periods when it is in the shadow of Mars for a portion of each orbit. The two are used together, maintaining almost identical charge during normal operations.

The spacecraft remains in communication with Earth and has been maintaining safe, stable temperatures and power, but has suspended its science observations and its service as a communications relay for Mars rovers. Normal voltage has been restored, and the spacecraft is being monitored continuously until the troubleshooting is complete.

It appears that all is under control. If MRO goes down, however it will a big loss for Mars research, as the spacecraft not only produces the highest resolution images of the ground, it also acts as one of several communications satellites between the Earth and the rovers on Mars. With two rovers there now, and at least two more planned for arrival in 2020, the loss of this communications link would be crippling.

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Massive flow on Mars

Massive flow on Mars

Cool image time! The image on the right, cropped to post here, comes from a Mars Reconnaissance Orbiter image that shows a massive relatively recent and dark slope streak that emanates out from a single point on the surface. (Note that the release at this link rotates the image so that north points down. I have rotated back so that north points up.)

Streaks form on slopes when dust cascades downhill. The dark streak is an area of less dust compared to the brighter and reddish surroundings. What triggers these avalanches is not known, but might be related to sudden warming of the surface.

These streaks are often diverted by the terrain they flow down. This one has split into many smaller streaks where it encountered minor obstacles. These streaks fade away over decades as more dust slowly settles out of the Martian sky.

Point of origin for flow

Location of flow, west of Olympus Mons

The MRO release focuses on the fingerlike breakup of the flow as it descends into sand-dune filled plain. What is more interesting to me is the terrain where this flow originated. A close-up of that area from the full image, shown on the right, reveals a feature that could be a wash running in line with the flow’s origin, and leading uphill to a dark feature that is a likely a cliff face. (The light in this image is coming from the southeast.)

This location, at 15.2N latitude, 214.9E longitude and shown by the small cross in the image on the right and captured from this page, is west of Olympus Mons, the largest volcano on Mars. This suggests to me that the originating feature might be an outlet from a lava tube, from which water suddenly seeped out to produce this massive slope streak. A look at the mesa from which this flow came, cropped from the full image and posted below the fold, shows numerous similar slope streaks of varying ages flowing out of this mesa, with some very faint because they occurred farther in the past. Some are even within the bowl at the top of the mesa.

Whether these come from lava tubes is definitely unclear, and I suspect I will be told by geologists not likely. The seeps however do suggest strongly that this mesa might be a very good location for future colonists to look for underground water ice. Since clouds form on the western slopes of Arsia Mons, the southernmost of the three giant volcanoes to the east of Olympus Mons, and that past glacial activity has been documented there, I wonder if some of these same conditions might also exist here, on the nearby terrain west of Olympus Mons.
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A good health check for Mars Reconnaissance Orbiter

Link here. The article outlines in good detail the spacecraft’s present condition, which is excellent despite being in space since 2005, as well as outlining the measures being taken to keep it operational into the 2020s.

This item is probably the biggest cause for concern:

For example, some HiRISE images taken in 2017 and early 2018 show slight blurring not seen earlier in the mission. The cause is under investigation. The percentage of full-resolution images with blurring peaked at 70 percent last October, at about the time when Mars was at the point in its orbit farthest from the Sun. The percentage has since declined to less than 20 percent. Even before the first blurred images were seen, observations with HiRISE commonly used a technique that covers more ground area at half the resolution. This still provides higher resolution than any other camera orbiting Mars — about 2 feet (60 centimeters) per pixel — and little blurring has appeared in the resulting images.

HiRISE is the spacecraft’s primary instrument, and its most valuable. If it goes, we will lose our best tool right now for looking in detail at the Martian surface.

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Weird Martian geology: Kaiser Crater

Kaiser Crater bedrock

Cool image time! This week JPL’s image site highlighted a picture taken by Mars Odyssey of the floor and dunes inside Kaiser Crater, located to the west of Helles basin in an area dubbed the Noachis Region.

To my eye, the Mars Odyssey picture was interesting, but not worth a post here on Behind the Black. However, I decided to take a look at what HiRise, the high resolution camera of Mars Reconnaissance Orbiter (MRO), had taken of the same area, just out of curiosity. A search at the master HiRise image site at the same latitude and longitude (-45 latitude, 180 longitude) showed that HiRise had imaged a part of the same area, but at much higher resolution.

When I zoomed in on this hi resolution image I came across some interesting and weird geology, cropped to show here on the right. Now this, I thought, is worth posting. Notice how the dark tracks, caused by dust devils, leave no tracks as they cut across the brighter areas. Obviously, these bright areas have no dust or sand, and are likely solid bedrock of some kind. The depressions might be craters, but they also might not. The raised area around the depressions might have been caused by the impact, or it might have been caused by some internal geological process that caused the depression while also raising the surrounding bulge. Since then the wind has been steadily depositing sand in the depressions, causing it to get trapped there.

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The mysterious dark splotches of Mars

The dark splotches of Mars

Cool image time! The image on the right, cropped and reduced in resolution to post here, shows one particular dark splotch in a region with several similar dark areas.

Geologists aren’t quite sure what to make of the dark splotch in the middle of this image, one of several similar dark splotches that extend east and west for over 100 kilometers. From measurements made in infrared, this and other dark splotches have what we call “high thermal inertia,” meaning that it heats up and cools down slowly. Scientists use thermal inertia to assess how rocky, sandy, or dusty a place is. A higher thermal inertia than the surrounding area means it’s less dusty.

The image below the fold shows at full resolution the area indicated by the white box. It provides me no clue as to the cause for the darker color. I think we can speculate all we want, but the truth is that we simply don’t have enough information. We need a closer look, including boots on the ground, to figure this out.
» Read more

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Mars or a bacterial cell?

Mars's southern polar regions

Cool image time! The image on the right, reduced and cropped to show here, was taken by Mars Reconnaissance Orbiter and shows just one spot in Mars’s southern polar regions. The surface only looks like bacteria because the basic structure of both is based on fractals. Scientists call this area “swiss-cheese terrain” because of the many holes that have opened up there.

The texture is very alien, bearing more of a resemblance to the universe of the very small, rather than the universe far, far away. But if this is a polar cap, then why does it not look like the polar caps on Earth? Indeed, there is no equivalent terrain observed here on Earth.

The so-called “Swiss cheese terrain,” referencing the numerous holes of the region, is a product of seasonal exchange between the surface and the Martian atmosphere. With a predominantly carbon dioxide content at 98 percent, the colder temperatures condense the gas out of the atmosphere to produce dry ice. The prevalence of water is more concentrated in the north, leaving the South polar region more carbon dioxide rich, and it’s this difference in composition that generates the unusual texture of the Swiss cheese terrain.

Be sure and take a look at the full resolution image. It is quite wild.

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A Martian Journey

The exploration of the solar system has barely begun. Though we regularly get to see some spectacular images taken by the fleet of unmanned planetary probes that now circle or rove the various planets throughout the solar system, we mustn’t think we have seen very much. In truth, we have only gotten a very distant glimpse of only a few tiny spots, most of which have been viewed from very far away. Even at the highest resolution the images do not really tell us what it really will be like when we can stroll across those surfaces routinely.

To give you an idea of how much remains hidden, let’s take a journey inward from Mars orbit. The image below looks down on a good portion of the Martian globe, with the giant volcano Olympus Mons on the left, its three companion volcanoes in line to the east, and the vast valley of Valles Marineris east of these. This valley would cover the continental United States almost entirely, and extend significantly beyond into the oceans on either side.

Olympus Mons and Valles Marineris

This was essentially our first good look at Mars, taken from orbit by Mariner 9 in 1971.
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Near the Martian south pole

Near the Martian south pole

Cool image time! The image above, reduced and cropped to show here, shows an area at 87 degrees south latitude, not far from the south pole of Mars and in the region at the edge of its icecap of dry ice.

It is late summer in the Southern hemisphere, so the Sun is low in the sky and subtle topography is accentuated in orbital images.

We see many shallow pits in the bright residual cap of carbon dioxide ice (also called “Swiss cheese terrain”). There is also a deeper, circular formation that penetrates through the ice and dust. This might be an impact crater or it could be a collapse pit.

Because of the low Sun angle the bottom of the deep pit is poorly lit, making it hard to determine the pit’s nature. What can be seen at its bottom however are some patches of carbon dioxide ice, melting in the same manner as the dry ice in the surrounding terrain. Also, the dust pattern surrounding the pit indicates the prevailing winds at this location, consistently blowing to the northeast.

I am certain there will be additional photos taken of this pit, when the Sun is higher in the sky and its floor is thus better illuminated.

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The soft avalanches of Mars

Krupac Crater gullies

Cool image time! The image on the right, reduced in resolution to show here, shows the gullies flowing down Krupac Crater on Mars. Be sure to check out the original, released today by the Mars Reconnaissance Orbiter science team, since they have enhanced the colors to bring out the sandy flows, noting as well that while most of these gullies are found in higher latitudes, this crater at 7.8 latitude has them as well.

Although large gullies (ravines) are concentrated at higher latitudes, there are gullies on steep slopes in equatorial regions. An enhanced-color closeup shows part of the rim and inner slope of Krupac Crater located just 7.8 degrees south of the equator.

The colors of the gully deposits match the colors of the eroded source materials. Krupac is a relatively young impact crater, but exposes ancient bedrock. Krupac Crater also hosts some of the most impressive recurring slope lineae (RSL) on equatorial Mars outside of Valles Marineris.

Below I have cropped out a small section showing, at full resolution, the termination point of one of these flows, indicating where this section is on the larger image to the right. This avalanche is clearly not liquid, though it has a very sandy and soft nature, suggesting — as some scientists have theorized — that liquid from below the surface might have played a part in its flow.

It is important in looking at these images to repeatedly remind yourself that the gravity here is about one third that of Earth, and thus the angle of repose will be different, and that avalanches will behave very differently in this environment. Moreover, Mars’s far colder climate will also effect things. The avalanche we are looking at could not happen in this way on Earth.

close-up of flow

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Strange beat-up Martian terrain

Strange terrain

Cool image time! The image above, taken by Mars Reconnaissance Orbiter and cropped to show here, reveals some very strange terrain, pounded by numerous impacts. The full color-enhanced image, which only covers a small area of the much larger strip image, shows a rough surface that on Earth would definitely be labeled “badlands.”

The very tiny cropped section above especially intrigued me because of the pronounced cliff that appears to be the north wall of a crater in which the east, west, and south walls have eroded away. The riverlet-like flows down the cliff-face are also intriguing, as are the cross-crossing features in the crater floor.

Make sure you look at the full images. Quite strange and fascinating. Even though the complete image strip isn’t color enhanced. it is filled with many interesting geological forms. I haven’t yet been able to find the spot shown by the color-enhanced section, but it is there nonetheless. I wonder if any of my readers can locate it.

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The Earth and Moon, as seen from Mars

The Earth and Moon as seen from Mars

Cool image time! The image above, a composite of four separate Mars Reconnaissance Orbiter pictures, was taken on November 20, 2016.

Each was separately processed prior to combining them so that the moon is bright enough to see. The moon is much darker than Earth and would barely be visible at the same brightness scale as Earth. The combined view retains the correct sizes and positions of the two bodies relative to each other.

The reddish region on Earth is Australia, with Antarctica the bright white area below that.

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Lace on Mars

Lace on Mars

Cool image time! The image on the right, cropped and reduced in resolution to show here, was taken by Mars Reconnaissance Orbiter June 21, 2016. It shows a region in the high northern latitudes, 80 degrees.

Some seasonal ice on Mars is transparent so that the sunlight penetrates to the bottom of the ice. Heat from this sunlight can turn the ice directly into a gas in a process called sublimation and this gas can scour channels in the loose dirt under the ice. Channels formed by sublimation of a layer of seasonal dry ice are so dense in this area that they look like lace. Gas flow erodes channels as it escapes to the surface of the overlying seasonal ice layer seeking the path of least resistance.

The resolution of the full image is 9.7 feet per pixel. This means that if Curiosity was driving across this surface we would see it. I guarantee however that Curiosity would not find driving here very easy. The ice surface is likely very delicate, and would likely cause any vehicle to bog down. The surface is also likely very alien-looking, which makes me very much want to see what it looks like, up close. This look will unfortunately have to wait, as we as yet do not have the right technology to do it. We would need I think a drone, capable of flying in Mars’s thin atmosphere.

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The weird south pole of Mars

Mars' south pole region

Cool image time (literally)! The photo above, cropped slightly to show here, was taken by Mars Reconnaissance Orbit (MRO) in August 2016 and was released today as part of the monthly release of captioned images. And though it looks like a fractal computer-generated animation still, it is instead real, showing the strange and quite alien terrain that routinely forms at the carbon dioxide ice cap there.

The polar cap is made from carbon dioxide (dry ice), which does not occur naturally on the Earth. The circular pits are holes in this dry ice layer that expand by a few meters each Martian year. New dry ice is constantly being added to this landscape by freezing directly out of the carbon dioxide atmosphere or falling as snow. Freezing out the atmosphere like this limits how cold the surface can get to the frost point at -130 degrees Celsius (-200 F). Nowhere on Mars can ever get any colder this, making this this coolest landscape on Earth and Mars combined!

This region is about 4 degrees north of the south pole itself.

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MRO color images of Schiaparelli crash site

Schiaparelli crash site

The image above, cropped from a wider image released today by the Mars Reconnaissance Orbiter science team, shows the Schiaparelli impact sites in color and in very high resolution. There are also high resolution images of the heat shield and parachute/back shell. As they note in describing the above image,

Where the lander module struck the ground, dark radial patterns that extend from a dark spot are interpreted as “ejecta,” or material thrown outward from the impact, which may have excavated a shallow crater. From the earlier image, it was not clear whether the relatively bright pixels and clusters of pixels scattered around the lander module’s impact site are fragments of the module or image noise. Now it is clear that at least the four brightest spots near the impact are not noise. These bright spots are in the same location in the two images and have a white color, unusual for this region of Mars. The module may have broken up at impact, and some fragments might have been thrown outward like impact ejecta.

In other words, the lander crashed hard when it hit the ground, throwing pieces and ground material everywhere.

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New details emerge of Schiaparelli crash site

Schiaparelli crash site

A new high resolution image from Mars Reconnaissance Orbiter’s HIRISE camera, reduced in resolution on the right, confirms that Schiaparelli crashed into the ground on October 19.

The scene shown by HiRISE includes three locations where hardware reached the ground. A dark, roughly circular feature is interpreted as where the lander itself struck. A pattern of rays extending from the circle suggests that a shallow crater was excavated by the impact, as expected given the premature engine shutdown. About 0.8 mile (1.4 kilometers) eastward, an object with several bright spots surrounded by darkened ground is likely the heat shield. About 0.8 mile (1.4 kilometers) south of the lander impact site, two features side-by-side are interpreted as the spacecraft’s parachute and the back shell to which the parachute was attached.

The center insert is a close-up of the impact site on the left, which clearly shows that the lander hit the ground hard, producing impact ejecta. That the rays are somewhat asymmetric also suggests that Schiaparellit hit the ground at an oblique angle.

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MRO images Schiaparelli on Mars

before and after Schiaparelli

A comparison of images taken by Mars Reconnaissance Orbiter before and after Schiaparelli’s failed attempt to land on Mars have revealed changes that are likely the lander on the surface. The image on the right is a composite that I’ve made showing the two images. The black spot near the top and the white spot near the bottom are not in the first image.

It is thought that the white spot is likely Schiaparelli’s parachute, while the dark spot is thought to be the lander’s impact point.

The larger dark spot near the upper edge of the enlargement was likely formed by the Schiaparelli lander. The spot is elliptical, about 50 by 130 feet (15 by 40 meters) in size, and is probably too large to have been made by the impact of the heat shield.

The large size of the dark spot suggests that the lander hit the ground hard enough to create this large scar.

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Fossilized rivers on Mars

The uncertainty of science: Using high resolution images from Mars Reconnaissance Orbiter scientists have identified more than 10,000 miles of fossilized rivers on Mars.

The new study examined images covering an area roughly the size of Brazil at a much higher resolution than was previously possible – six metres per pixel compared to 100 metres per pixel. While a few valleys were identified, the team revealed the existence of many systems of fossilised riverbeds which are visible as inverted channels spread across the Arabia Terra plain.

The inverted channels are similar to those found elsewhere on Mars and Earth. They are made of sand and gravel deposited by a river and when the river becomes dry, the channels are left upstanding as the surrounding material erodes. On Earth, inverted channels often occur in dry, desert environments like Oman, Egypt, or Utah, where erosion rates are low – in most other environments, the channels are worn away before they can become inverted. “The networks of inverted channels in Arabia Terra are about 30m high and up to 1–2km wide, so we think they are probably the remains of giant rivers that flowed billions of years ago. Arabia Terra was essentially one massive flood plain bordering the highlands and lowlands of Mars. We think the rivers were active 3.9–3.7 billion years ago, but gradually dried up before being rapidly buried and protected for billions of years, potentially preserving any ancient biological material that might have been present,” added Joel Davis.

These geological forms are different than most of the more well-known Martian channels in that they are not channels but meandering riverlike ridges, higher than the surrounding terrain. Arabia Terra, where they are located, is a transition region in the northern mid-latitudes between Mars’s southern highlands and its northern flat plains, where some believe an ocean once existed.

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A glacier on Mars

A glacier on Mars

Cool image time! The image on the right, cropped and reduced in resolution, is a Mars Reconnaissance Orbiter picture taken on March 28, 2016 of a glacial flow coming down off of mountains in Mars’ northern mid-latitudes. The mountains are to the south and beyond the bottom right. The flow is to the northwest. The full image can be found here. As noted on the image site,

These flow-like structures were previously called “lobate debris aprons,” but the Shallow Radar (SHARAD) instrument on [Mars Reconnaissance Orbiter] has shown that they are actually debris-covered flows of ice, or glaciers. There is no evidence for present-day flow of these glaciers, so they appear to be remnants of past climates.

Need I say it? This is water, on Mars, and in abundance. Think that this might be good real estate when those first settlers arrive?

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New images of failed Beagle 2 on Mars

By carefully improving the resolution of images taken by Mars Reconnaissance Orbiter of the landing site of the 2003 European Mars lander Beagle 2, scientists think the lander might have successfully landed but failed to deploy its solar shields completely.

Showing a bright blip in dusty terrain, the new picture is four times the resolution of previous images. The image adds weight to the theory that the diminutive spacecraft – just under a metre in diameter – landed as planned on Mars in 2003, but failed to fully unfurl its solar panels. “Given the size of Beagle 2, even with super-resolution images you are not likely to see more than a series of blobs because it is so small,” said Mark Sims, of the University of Leicester and former mission manager for Beagle 2. “What it does show is that it is on the surface and it is at least partially deployed.”

The technique they have developed for improving image resolution will also be useful to tease out new details about the Martian surface.

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An avalanche on Mars, as it happens

Avalanche on Mars

Cool image time! In their routine monitoring for avalanches at the layered deposits at the Martian north pole, the Mars Reconnaissance Orbiter science team captured the avalanche on the right, as it happened.

This picture managed to capture a small avalanche in progress, right in the color strip. … The small white cloud in front of the brick red cliff is likely carbon dioxide frost dislodged from the layers above, caught in the act of cascading down the cliff. It is larger than it looks, more than 20 meters across, and (based on previous examples) it will likely kick up clouds of dust when it hits the ground.

They note that avalanches in this area of Mars are common in the spring when things are warming, and have been documented previously, but possibly not so dramatically.

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A detailed status update on Mars Reconnaissance Orbiter

Link here. The orbiter, which continues to send down spectacular images while acting as a workhorse communications relay for the rovers on the ground, appears to be in reasonable shape. It has enough fuel to operate into the late 2020s. The other known problems appear manageable.

Zurek said the most significant technical issue aboard MRO is in one of the spacecraft’s inertial measurement units used to determine the orbiter’s motion and orientation. Zurek said a laser inside one of the unit’s gyroscopes is showing signs of aging, and ground controllers are trying to coax the sensor along by switching to an identical backup unit.

In the meantime, engineers are working on changing the orbiter’s navigation logic to rely on star trackers in case both navigation sensors go down, Zurek said. One of the gimbals used to point MRO’s power-generating solar panels toward the sun is also sticky, a sign of age-related “arthritis” aboard the spacecraft, Zurek said.

MRO also abruptly switches to its backup “B side” computer on occasion, temporarily interrupting scientific observations for a few days each time. Zurek said the orbiter’s ground team has learned to deal with the problem, which has escaped diagnosis with a root cause.

Of course, there are always the unknown problems that haven’t yet popped up that could be devastating. Let us hope none appear soon, since NASA will not be able to send a replacement until 2022, at the earliest.

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The wild Martian terrain

Yardangs on Mars

This week’s image release from the high resolution camera on Mars Reconnaissance Orbiter illustrate well the wild and mysterious geology of the Martian surface. I include cropped sections from two images here, just to give you a taste. Go to the link to do your own exploring.

The image to the right is a cropped and scaled down version of the original image, so the details are not easily seen. Make sure you look at the original. The strange yardang ridges, all aligned alike, rise up out of a relatively smooth plain.

Yardangs are formed when a surface that is composed of materials of differing strengths (i.e., of both harder and softer materials) is shaped by the abrasive action of sand and dust carried by the wind. In this case, and given the proximity of the Apollonaris Patera volcanic center, we think that these wind-carved deposits are comprised of volcanic ash and pyroclastics that erupted from Apollonaris when it was last active in the not-too-distant geologic past. Over time, the softer materials (likely volcanic ash) were eroded away, leaving behind the harder materials in the form of elongated ridges that are parallel to the direction of the prevailing wind. The end result is a stunning, out-of-this-world display of yardangs, sculpted with the artistic chisel of the Martian wind.

That’s the theory, anyway. The actual geological process that formed these ridges is probably a lot more complicated.

The image below the fold illustrates the on-going surface activity on Mars.
» Read more

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Layered mesas inside Martian crater

Layered mesas inside a Martian crater

Cool image time! In their weekly release of new images, the hi-resolution camera team for Mars Reconnaissance Orbiter have posted a wonderful image of the complex layering and terracing inside Spallanzani Crater, located in the high latitudes of the red planet’s southern hemisphere. The image on the right is only one small section of the much larger image.

So what is the composition of these layers? Spallanzani Crater lies in the high latitudes of the Southern hemisphere (around 60 degrees in latitude) so there is a good possibility that the deposits are ice-rich. If we look more closely we will notice fractured mounds, which sometimes indicate the presence of subsurface ice. Another interesting observation is the presence of grooves in the shaded slopes of some of the layers. Perhaps these grooves formed because of the sublimation (the direct transfer of solid ice to water vapor) of ice from these slopes since slopes tend to get warmer than the surrounding terrains.

This image hardly shows a breakthrough discovery, but I like it because it illustrates nicely the wonderful but very alien landscape of Mars. To walk its surface will be a daily adventure for its first colonists.

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Mars Reconnaissance Orbiter photographs Comet Siding Spring

During Comet Siding Spring’s flyby of Mars on Sunday Mars Reconnaissance Orbiter was able to capture an image of the comet’s nucleus.

Prior to its arrival near Mars astronomers estimated the nucleus or comet’s core diameter at around 0.6 mile (1 km). Based on these images, where the brightest feature is only 2-3 pixels across, its true size is shy of 1/3 mile or 0.5 km.

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