Tag Archives: Mars

Solar storm activates global aurora on Mars

The strong solar flare that occurred earlier this month was strong enough to activate a global aurora on Mars.

The solar event on Sept. 11, 2017 sparked a global aurora at Mars more than 25 times brighter than any previously seen by the MAVEN orbiter, which has been studying the Martian atmosphere’s interaction with the solar wind since 2014. It produced radiation levels on the surface more than double any previously measured by the Curiosity rover’s Radiation Assessment Detector, or RAD, since that mission’s landing in 2012. The high readings lasted more than two days.

Strangely, it occurred in conjunction with a spate of solar activity during what is usually a quiet period in the Sun’s 11-year sunspot and storm-activity cycle. This event was big enough to be detected at Earth too, even though Earth was on the opposite side of the Sun from Mars.


Mangalyaan passes three years in Mars orbit

India’s Mangalyaan orbiter has passed its third anniversary operating in Mars orbit.

The spacecraft could last as long as five more years before running out of fuel. Though it has five instruments and has taken more than 700 images, its importance so far is not in the science it has done but in what it has taught Indian engineers for running future more sophisticated missions.


Curiosity tops Vera Rubin Ridge

Curiosity's view from on top of Vera Rubin Ridge, sol 1812

The image above is a reduced resolution version of a panorama created by reader Phil Veerkamp of images downloaded today from Curiosity. If you click on the image you can see the full resolution image. It looks to more to the east than the panorama shown in my September 6 rover update, revealing more of the type of surface the rover will have to cross on its drive forward on this new geological layer called the Hematite Unit.

Curiosity has now topped Vera Rubin Ridge, but the plateau above is really not as flat as the image implies. The Hematite Unit that the rover is now traversing still climbs upward, and they will continue to gain altitude now with almost every drive.


Mars rover update: September 6, 2017

Summary: Curiosity ascends up steepest part of Vera Rubin Ridge, getting just below the ridgetop, while Opportunity inspects its footprint in Perseverance Valley.


For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Curiosity panorama, Sol 1807

Curiosity's location, Sol 1802

Since my last update on August 11, Curiosity has been slowly working its way along the base of Vera Rubin Ridge, and up its slope. Today’s update from the science team describes how the rover is now on the steepest part of that slope, which is also just below the ridgetop. The panorama above looks east at the ridge, at the sand-duned foothills in the Murray Formation that Curiosity has been traversing since March 2016, and the crater plains beyond.

The image on the right shows Curiosity’s approximate position, with the point of view of the panorama indicated. The image also shows their planned upcoming route across the Hematite Unit. As they note in their update:

Curiosity now has great, unobstructed views across the lowlands of Gale crater to the rear of the rover. The view is improving as the air becomes clearer heading into the colder seasons. The first image link below shows a Navcam view into the distance past a cliff face just to the left of the rover. The image is tilted due to the to the unusually high 15.5 degree tilt of the rover as it climbs the ridge. Part of Mount Sharp is in the background. The second link shows an image looking ahead, where we see much more rock and less soil. The foreground shows that some of the pebbles are relatively well rounded. The rock face up ahead is smooth, which will mean easier driving.

That report I think is somewhat optimistic.
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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.


SpaceX postpones Mars Dragon missions

Based on statements from one NASA official, it appears that SpaceX has put its plans to fly a Dragon capsule to Mars on “the back burner.”

Jim Green, head of NASA’s planetary science division, told Spaceflight Now in an interview that SpaceX has told the agency that it has “put Red Dragon back on the back burner.”

“We’re available to talk to Elon when he’s ready to talk to us … and we’re not pushing him in any way,” Green said. “It’s really up to him. Through the Space Act Agreement, we’d agreed to navigate to Mars, get him to the top of the atmosphere, and then it was up to him to land. That’s a pretty good deal, I think.”

It is my impression that, because NASA has forced SpaceX to give up on propulsive landing of its Dragon manned capsules, the company cannot afford to invest the time and money on it themselves, and thus do not have a method yet for landing a Dragon on Mars. Thus, they must postpone this program.


Water ice found near Martian equator

A review of old Mars Odyssey data has revealed the presence on Mars of water ice near the planet’s equator.

The article makes a big deal about the importance of this discovery for the possibility of past or even present life on Mars. I say that its real importance relates to future colonists, and cannot be understated.

I should add one caveat: The resolution of the data is not great, 290 kilometers, which leaves a lot of room for error.


Mars rover update: August 11, 2017

Summary: After a two week hiatus because the Sun was between the Earth and Mars and blocking communications, both rovers are once again on the move.


For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Curiosity panorama, Sol 1782

Vera Rubin Ridge close-up

Since my last update on July 12,, Curiosity spent most of the month waiting out the solar conjunction that placed the Sun between the Earth and Mars and blocked communications. In the past few days, however, the rover has begun to send down images again while resuming its journey up Mt. Sharp. The panorama above, reduced to show here, was taken by the rover’s left navigation camera, and shows the mountain, the ridge, and the route the rover will take to circle around the steepest sections to get up onto the ridge. To see the full resolution panorama click on the picture.

To the right is a full resolution section of the area in the white box. As you can see, the geology of the ridge is many-layered, with numerous vertical seams or cracks. In order to track the geological changes across these layers as the rover climbs, the science team is as expected taking a systematic approach.

Lately, one of our biggest science objectives is to conduct bedrock APXS measurements with every 5-meter climb in elevation. This allows us to systematically analyze geochemical changes in the Murray formation as we continue to climb Mount Sharp. Yesterday’s drive brought us 6 meters higher in elevation, so another touch and go for today it is!

Below is a cropped and reduced resolution image of the most recent orbital traverse image, dated sol 1754. The dotted line shows where I think the rover’s has traveled in the last 28 sols. I have also annotated what I think is the point of view of the panorama above.
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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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New images downloaded from Curiosity for the first time in two weeks

For the first time since communications with Mars ceased two weeks ago because the orbits of the Earth and Mars had placed the Sun in between, new images have been downloaded from Curiosity.

For the past two weeks, the last raw images posted had been from sol 1760. Today, the Hazard Avoidance Cameras (Hazcams) added daily images through sol 1774 (taken as per previously uploaded commands). The images all show the same view, the part of Vera Rubin ridge that the rover has been circling around to get to the place where it will be easier to climb up. The science team probably programmed this sequence so that they could look for any changes from wind, over time.

No new images from either Curiosity’s other cameras or from Opportunity have yet appeared, but I expect this to soon change.


Opportunity enters Perseverance Valley

Opportunity in Perseverance Valley

Just prior to the drop in communications this week because of the Sun’s position between the Earth and Mars, Opportunity was ordered down into Perseverance Valley, where it will sit until the return of full communications.

Opportunity entered Perseverance Valley on the west rim of Endeavour crater. The rover is positioned within the valley where she will spend the solar conjunction period.

Solar conjunction is when the Sun comes between Earth and Mars, which occurs about once every 26 months. During this time, there will be diminished communications to Opportunity. More on solar conjunction here: https://mars.jpl.nasa.gov/allaboutmars/nightsky/solar-conjunction/

Two weeks of commanding have been uploaded to the rover to keep her active during solar conjunction with short communications with the Mars orbiters during the period.

The image on the right, reduced to show here, was taken by the rover’s navigation camera looking back uphill at the crater’s crest and the rover’s tracks in the valley. For the scientists the tracks are important because they reveal what the surface of the valley is like, which will help them determine whether it was formed from flowing water, flowing ice, or wind.

Even more significant, this initial drive into the valley means the science team has decided that either the wheel issues in June were not serious enough to prevent them from making this downhill trip, or the science is important enough that they are willing to risk the rover to get that science.


Opportunity takes panorama at top of Perseverance Valley

On top of Perseverance Valley

During Opportunity’s two week pause in its travels in June as engineers tried to diagnose a problem with its left-front wheel, it took a wide panorama of the surrounding terrain, including the top of Perseverance Valley, released today.

The full panorama, shown above in reduced resolution, is a bit confusing. The head of Perseverance Valley to the northeast is on the right. The view straight ahead looks west, away from the crater. The hill and raising terrain on the left is the crater rim to the south of Perseverance Valley. The panorama is not a complete 360 degree view, as it does not include a direct view to the east and into Endeavour Crater itself.

Be sure and click on the link and look at the full image. The top of the valley is really interesting to view. Was it formed by wind or water or water ice? They hope to find out.


Hubble shoots movie of Phobos

Phobos over Mars

Cool image time! By taking a quick series of thirteen images, the Hubble Space Telescope was able to shoot a short movie of the rotation of Phobos above the surface of Mars. The gif animation on the right is the smaller of the two animations released today. Be sure and view the full resolution version.

What is even cooler is that movie was apparently unplanned. From the link:

Over the course of 22 minutes, Hubble took 13 separate exposures, allowing astronomers to create a time-lapse video showing the diminutive moon’s orbital path. The Hubble observations were intended to photograph Mars, and the moon’s cameo appearance was a bonus.

In terms of science this movie has a somewhat limited value. In terms of space engineering it is triumph, and once again illustrates the unprecedented value of having an optical telescope in space. Woe to us all when Hubble finally dies, as we have no plans to replace it.


Mars rover update: July 12, 2017

Summary: Curiosity looks at some big dune ripples, then creeps up hill. Opportunity tests its wheels.


For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

The interior of a dune ripple

Since my last update on June 23,, Curiosity has worked its way around and, for a few days, even into the small sandy field at the base of Vera Rubin ridge. The scientists noticed that the sandy here had a series of large ripples, and they wanted to take a close look at at least one. The image on the right, cropped to show here, was taken shortly after they had the rover drive through one ripple in order to expose its interior. You can see the robot arm directly above the cut created by the rover’s wheels. On the cut’s wall several distinctly different toned layers are visible. A close look reveals that they are wavy, and probably indicate numerous and repeated overlays as the wind brushes a new layer of dust on top of old layers, time after time. The different tones indicate a change in the material’s composition, which could reveal something about some past events in either Mars’ weather or geology.

In order to decipher this information, however, they will need to be able to date the layers, and figure out when each tonal change happened. I am not sure Curiosity can do this, especially since they have not scooped up any of this dust for later analysis.

They are now approaching Vera Rubin Ridge, and should climb up onto in the coming weeks. At that point they will move off the Murray Formation, where they have been since March 2016, made up of dried and ancient crushed mud, and up onto a lighter, yellowish layer of rock, dubbed the Hematite Unit. This October 3, 2016 press release. gives a good outline of the geology of these regions.
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Improved software uploaded to Curiosity to extend wheel life

Engineers have designed and uploaded new software to Curiosity to better protect and use the rover’s wheels as it travels over rough terrain.

The software, referred to as traction control, adjusts the speed of Curiosity’s wheels depending on the rocks it’s climbing. After 18 months of testing at NASA’s Jet Propulsion Laboratory in Pasadena, California, the software was uploaded to the rover on Mars in March. Mars Science Laboratory’s mission management approved it for use on June 8, after extensive testing at JPL and multiple tests on Mars.

The timing is important, because Curiosity is about to move into terrain that looks far rougher than the ground it has so far traversed.


A river canyon on Mars

A river on Mars

Cool image time! The image on the right, reduced in resolution significantly to show here, was taken by the Themis camera on Mars Odyssey, and shows an unnamed canyon on Mars. Be sure to click on the image to see the full resolution version.

This canyon of course no longer has anything flowing in it. Moreover, it is not clear whether this was formed by water or lava. Unfortunately, the image is part of a series of “Art images” from Mars Odyssey, where they pick an image and suggest it looks like something else. In this case, they are claiming this looks like a “snake, slithering down the image.” Cute, but not very helpful. And unfortunately, they don’t add any further details at all about the image or its location. The context image suggests this canyon is next to a volcano.

After doing further research at the Themis image site, I was able to locate this image on Mars (using latitude 32.0515 and longitude 152.236 given at the link) and look at the images surrounding this one. Further research identified the volcano as Hecates Tholus in the Elyesium Plantia region to the west of Mars’s giant volcanoes.

Looking at all the nearby Mars Odyssey images, it appears that there are a lot of flows like this in this area, and all of them appear to be lava flows, with this one being the largest. A close look at the area just to the south of where the deep canyon opens out shows that the small surface flow draining into the canyon also appears to sit on much larger surface flows (at least two) that left the surface higher than the surrounding terrain.

Elyesium Plantia itself is a plateau, somewhat close to the border between Mars’s southern highlands and the northern plains where some scientists think an ocean might have once existed. Thus, it makes sense that the canyon drains north, as it is following the dip down to those northern low plains.


Mars rover update: June 23, 2017

Summary: Curiosity continues up hill. Opportunity has wheel problems.


For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

The march up Mt Sharp continues. Since my last update on May 15, Curiosity has continued working its way up towards what the science team has named Vera Rubin Ridge, the beginning of a lighter, yellowish layer of rock, dubbed the Hematite Unit, that sits higher up the mountain’s slope. They have been traveling on the Murray Formation now for more than a year, since March, 2016, so entering this new layer of geology is eagerly anticipated by the science team. (This October 3, 2016 press release. gives an overall picture of the geology Curiosity is traversing.)

Reader Phil Veerkamp sent me a beautiful panorama he stitched together from recent Curiosity images of Vera Rubin Ridge, directly to the south of the rover and higher up hill. Below is a reduced resolution version. Be sure you click on it to explore the full resolution image. This is a new type of terrain, significantly different than anything Curiosity has seen up to now. It also appears that the rover will see far less dust, and might be traveling mostly over solid boulders. Below I have cropped out a very small section of the ridge line near the center of the full image, just to illustrate this.
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A dust-off broom for Mars

Romanian engineers have developed a small plasma jet capable of blowing Martian dust from solar panels and other equipment that can be used by future missions.

The “plasma broom” solution developed by Ticoş and colleagues uses bursts of plasma jet produced by a simple plasma accelerator. When a large current is passed through two electrode plates separated by a field of rarefied gas, the voltage difference between the two electrodes ionizes the gas, creating the plasma. In the broom, this is done with a coaxial gun – the two metal electrodes are arranged as an inner rod within a hollow cylindrical shell. The discharge current flowing through the central rod electrode produces a magnetic field, which, together with the electric field, exerts a Lorentz force on the ionized gas that expels it. “The trick is that you need a quite high current in order to produce a reasonable magnetic field and this can be achieved more conveniently in a pulsed operation,” Ticoş explains. “For a fraction of a second (100 µs) the current is very high (several kiloamps) and the force pushing the plasma is quite strong.” During a pulse, the plasma is expelled at a very high speed – several kilometres per second – and so can simply blow dust away from an area two to four times bigger than the diameter of the jet.

An advantage of the plasma broom is that it uses low-pressure CO2 as the gas between the electrodes. This is particularly ideal for operation on Mars as the atmospheric pressure there is 150 times lower than on Earth and the atmosphere is 96% CO2. This means the gun will be able to function in “open” Martian atmosphere without the need for a pump or gas bottle. Ticoş and colleagues have also considered the energy required for the cleaner to function on Mars. This depends on the voltage the gun operates at and can vary between a few hundred to a few thousand Joules per pulse. “We did an energy budget estimate taking into account the solar irradiance on Mars,” says Ticoş, “and it appears perfectly feasible to fire a few shots even on a daily basis for cleaning the solar panels, which will boost considerably the energy production rate.”

Essentially, they are using ion engine concepts to create a can of dust-off, using the Martian atmosphere itself as the can.

Hat tip Mike Buford.


Cumulative data from Curiosity shows Gale Crater lake stratified

The cumulative data from Curiosity since its arrival on Mars three and a half years ago shows that the lake that once filled Gale Crater lake had had a stratified chemical make-up.

Previous work had revealed the presence of a lake more than three billion years ago in Mars’ Gale Crater. This study defines the chemical conditions that existed in the lake and uses Curiosity’s powerful payload to determine that the lake was stratified. Stratified bodies of water exhibit sharp chemical or physical differences between deep water and shallow water. In Gale’s lake, the shallow water was richer in oxidants than deeper water was.

“These were very different, co-existing environments in the same lake,” said Joel Hurowitz of Stony Brook University, Stony Brook, New York, lead author of a report of the findings in the June 2 edition of the journal Science. “This type of oxidant stratification is a common feature of lakes on Earth, and now we’ve found it on Mars. The diversity of environments in this Martian lake would have provided multiple opportunities for different types of microbes to survive, including those that thrive in oxidant-rich conditions, those that thrive in oxidant-poor conditions, and those that inhabit the interface between those settings.”

While what Hurowitz says above is true, remember that this discovery provides zero evidence of past life on Mars. All it has done is teach us something about the different conditions in the lake at different depths.


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.


Curiosity data increases time water existed Gale Crater

New research using data from Curiosity has found evidence suggesting that significant water was present in Gale Crater for a very long time.

Lighter-toned bedrock that surrounds fractures and comprises high concentrations of silica — called “halos”— has been found in Gale crater on Mars, indicating that the planet had liquid water much longer than previously believed. The new finding is reported in a new paper published today in Geophysical Research Letters, a journal of the American Geophysical Union.

“The concentration of silica is very high at the centerlines of these halos,” said Jens Frydenvang, a scientist at Los Alamos National Laboratory and the University of Copenhagen and lead author of the new study. “What we’re seeing is that silica appears to have migrated between very old sedimentary bedrock and into younger overlying rocks. The goal of NASA’s Curiosity rover mission has been to find out if Mars was ever habitable, and it has been very successful in showing that Gale crater once held a lake with water that we would even have been able to drink, but we still don’t know how long this habitable environment endured. What this finding tells us is that, even when the lake eventually evaporated, substantial amounts of groundwater were present for much longer than we previously thought—thus further expanding the window for when life might have existed on Mars.”

The actual paper provides no time frame. What it does state is that for the halos to have formed requires a lot of time, and that during that time a lot of groundwater was required.


Mars rover update: May 15, 2017

This update could also be entitled, “Up and down into Martian gullies,” as that is what both rovers, Curiosity and Opportunity, are presently focused on doing.


Curiosity's position, Sol 1696 (May 12, 2017)

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

In the past month, since my previous April 21, 2017 update, Curiosity has been working its way up the dry wash, frequently stopping to inspect the rocky surface terrain within. As they note,

As we climb up Mount Sharp, recently over slopes of 4-6 degrees, we have seen more varied outcrop structures and chemistries than the rest of the Murray formation, and such changes catch the collective eye of the team.

Only in the last week have they shifted to the east, as planned. Their near term goal is the lighter, yellowish layer of rock, dubbed the Hematite Unit, that sits higher up the slope of Mount Sharp. As they have been traveling on the Murray Formation now for more than a year, since March, 2016, I am certain the science team is even more eager to get to this different layer of geology to find out what it is made of and why it is there.

You can get an overall view of the geology Curiosity is traversing from this October 3, 2016 press release. Below is a version of the traverse map shown at that site that I posted as part of my October 6, 2016 rover update, updated to show Curiosity’s present location. It is apparent that Curiosity is finally moving out of the foothills below Mount Sharp and beginning its climb up the mountain’s actual slopes.
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UAE reveals details on its 100 year Mars colonization plan

The United Arab Emirates (UAE) has unveiled some of the reasoning behind its plan to colonize Mars by 2117, including an overall outline of its long term approach.

“In the UAE, we live in a rough neighborhood,” Al Gergawi added. “Our neighborhood has over 100 million youth, with over 35 percent unemployment.”

This high rate of youth unemployment in the region has a well-known negative impact such as radicalisation and even terrorism, Al Gergawi explained. One of the rationales for the Mars 2117 programme, however, is to turn the circumstances of young people in the Middle East into a positive impact that engages them in meaningful goals involving education in science and technology. “This is the impact we’re betting on,” said Al Gergawi. “We want to enable the youth to play an active role in advancing the global efforts toward enhancing the Red Planet and other planetary bodies.”

…“The Mars 2117 Project is a long term project, where our first objective is to develop our educational system so our sons will be able to lead scientific research across the various sectors. The UAE became part of a global scientific drive to explore the space, and we hope to serve humanity through this project,” Abu Dhabi Crown Prince His Highness Sheikh Mohamed bin Zayed Al Nahyan added.

I wish them well. The aims and approach seem to be right, though the hill they need to climb is quite steep.


Two Dragon Mars missions in 2020?

It appears that SpaceX is considering flying two test Dragon capsules to Mars in 2020.

NASA’s manager of science missions, Jim Green, said on Tuesday that the 2020 launch window when Earth and Mars are in favorable alignment for relatively short transits is getting crowded. Speaking Tuesday at the Humans to Mars conference in Washington, DC, Green said, “Every 26 months, the highway to Mars opens up, and that highway is going to be packed. We start out at the top of that opportunity with a SpaceX launch of Red Dragon. That will be followed at the end of that opportunity with another Red Dragon. Those have been announced by SpaceX.” NASA plans to launch a Mars lander in 2020 as well.

Two Red Dragon missions in 2020 have not yet formally been announced by SpaceX. Company spokesman John Taylor told Ars he would have to look into the question of sending two Dragons to Mars in 2020. However, other industry sources told Ars this is definitely under consideration by SpaceX, although no final decisions have been made.

That would mean two Falcon Heavy launches that year, just for this. And it would happen long before NASA manages its first launch of a complete SLS rocket.


Europe considers a helicopter drone for future Mars missions

The European Space Agency is considering flying a technology demonstration helicopter drone on a future Mars mission.

Note that they don’t yet have the money to build this, and it appears that they don’t yet have a mission to fly it on. What they have done is just completed a preliminary study, which suggests the idea is feasible. They are now lobbying for more cash to move forward.


Curiosity’s last dune investigation

As Curiosity moves closer to the very base of Mount Sharp, it is presently making its last investigation of the various types of dunes found at the foot of the mountain.

From early February to early April, the rover examined four sites near a linear dune for comparison with what it found in late 2015 and early 2016 during its investigation of crescent-shaped dunes. This two-phase campaign is the first close-up study of active dunes anywhere other than Earth.

Among the questions this Martian dune campaign is addressing is how winds shape dunes that are relatively close together, on the same side of the same mountain, into different patterns. Others include whether Martian winds sort grains of sand in ways that affect the distribution of mineral compositions, which would have implications for studies of Martian sandstones. “At these linear dunes, the wind regime is more complicated than at the crescent dunes we studied earlier,” said Mathieu Lapotre of Caltech, in Pasadena, California, who helped lead the Curiosity science team’s planning for the dune campaign. “There seems to be more contribution from the wind coming down the slope of the mountain here compared with the crescent dunes farther north.”

The article also included a vague update on the status of Curiosity’s drill, out of commission since its drill feed mechanism had problems moving the drill up and down back in the fall of 2016.

Engineers are assessing how the use of vibration to deliver samples may affect the drill feed mechanism, which is used to move the drill bit forward and backwards. In addition, high winds at the linear-dunes location were complicating the process of pouring sample material into the entry ports for the laboratory instruments.

“A balky brake appears to be affecting drill feed mechanism performance,” said Curiosity Deputy Project Manager Steven Lee, of NASA’s Jet Propulsion Laboratory, Pasadena, California. “In some cases, vibration has been observed to change feed effectiveness, so we’re proceeding cautiously until we better understand the behavior. In the meantime, the engineering team is developing several methods to improve feed reliability.”

What this release does not say is whether they are any closer to solving the problem, or whether the drill is essentially out of business for the reminder of Curiosity’s life. To me, the silence on this question is deafening, and strongly suggests that they have decided the drill cannot be used, for the foreseeable future.


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


Mars rover update: April 21, 2017


Curiosity's position, Sol 1664 (April 10, 2017)

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Since my previous February 14, 2017 update, Curiosity has worked its way through the dunes and has emerged, as planned at the head of what looks like a dry wash flowing down from Mount Sharp. At the time I had predicted that the science team would then have the rover make a beeline to Mount Sharp, following the smoothest route. That prediction is almost certainly wrong. Instead, the scientists are probably going to have the rover zig-zag its way south into the dry wash so that they can study the geology there. This is what they have been doing, as shown on the traverse map to the right, which shows Curiosity’s location through Sol 1664 (April 10). Ideally I expect them to want to check out the flow areas of the central parts of the wash as well as the contact point on either side where the color of the terrain changes from dark to light. This appears to be what they doing now, two weeks later, based on this update posted yesterday.

The 23 m drive on Sol 1673 put Curiosity alongside Murray bedrock blocks that appeared to be capped with a different material, with a darker color and smoother texture relative to the Murray

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Scientists release geological map of potential landing site for 2020 rover

Researchers have released a detailed geological map of Northeast Syrtis Major, one of the prime candidate landing sites for NASA’s next Mars rover, scheduled for launch in 2020.

Within Northeast Syrtis are the mineral signatures of four distinct types of watery and potentially habitable past environments. Those minerals had been detected by prior research, but the new map shows in detail how they are distributed within the region’s larger geological context. That helps constrain the mechanisms that may have formed them, and shows when they formed relative to each other.

The lowest and the oldest layer exposed at Northeast Syrtis has the kind of clay minerals formed when rocks interact with water that has a fairly neutral pH. Next in the sequence are rocks containing kaolinite, a mineral formed by water percolating through soil. The next layer up contains spots where the mineral olivine has been altered to carbonate—an aqueous reaction that, on Earth, is known to provide chemical energy for bacterial colonies. The upper layers contain sulfate minerals, another sign of a watery, potentially life-sustaining environment.

Understanding the relative timing of these environments is critical, Mustard says. They occurred around the transition between the Noachian and Hesperian epochs—a time of profound environmental change on Mars.

This press release is very much an effort by these scientists to influence the final landing site choice. They like this site, and they want to convince other scientists that are part of the project to agree with them.

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