Tag: science

Perseverance gets a glimpse into the history of Jezero crater

10:03 am

A glimpse into the history of Jezero Crater
Click for full image.

Cool image time! The photo to the right, cropped, reduced, and enhanced to post here, was taken on August 17, 2022 by one of Perseverance’s high resolution camera. It shows the exposed layers of a nearby cliff face that comprises the end of the delta that once flowed into Jezero Crater in the distant Martian past.

My guess is that this cliff is about 20 feet high. The more massive, thicker and younger layers near the top, compared to the thinner and older layers below, suggest a major change in the cyclic events. The early cycles that lay down this delta were initially shorter and able to place less material with each cycle, while the last few cycles were longer, producing thicker layers.

The difference in layers also strongly suggests that all the blocks at the foot of the cliff fell from more massive layers at the top. Material that broke off from the lower thinner layers has likely long ago eroded away.

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InSight power levels remain steady on Mars

4:54 pm

InSight's status through August 21, 2022

The InSight science team today released its weekly update on the lander’s ability to generate power from its dust-covered solar panels, I have charted the new numbers, through August 21, 2022, on the graph to the right. From the update:

InSight was generating an average of 400 watt-hours of energy per Martian day, or sol. The tau, or level of dust cover in the atmosphere, was estimated at .88 (typical tau levels outside of dust season range from 0.6-0.7).

For the fourth straight week the daily power level remained steady, not dropping as predicted by engineers to a point in August that the mission would end. As it appears the seismometer can function when the panels produce 400 watt-hours per day, the lander is thus holding its own instead of shutting down.

That the amount of dust in the atmosphere increased slightly is both good and bad news. The good news: Even with slightly more dust, InSight’s power levels did not drop. The bad news: There is still plenty of dust in the air that can settle on the solar panels and further degrade their ability to generate electricity.

InSight’s future is thus a day-to-day thing, though it appears at this moment that it can likely continue to gather earthquake data for another week.

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Ingenuity completes 30th flight

3:57 pm

The Mars helicopter Ingenuity sometime during the August 20-21 weekend successfully completed its 30th flight, a short hop designed to check out its systems after a two-month pause during the dusty Martian winter.

The tweet mentions the flight was also an effort to clear off any dust that settled on the helicoper’s solar panels. In addition, the flight tested precision landings in anticipation of the present plans to use a helicopter on a future mission to recover Perseverance’s Martian samples.

The tweet provides no information about the flight, but this update from August 19, 2022 describes the flight plan:

When things get underway, the helicopter will climb to a max altitude of 16.5 feet (5 meters), translate sideways about 6.5 feet (2 meters), and then land. Total time aloft will be around 33 seconds.

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Storm fronts on Jupiter

10:27 am

Storm front on Jupiter
Click for full image.

Cool image time! The picture to the right, cropped and reduced to post here, was processed by citizen scientist Thomas Thomopoulos from a raw image taken by the Jupiter orbiter Juno on August 17, 2022.

The orbiter was 18,354 miles above the cloud tops when the image was snapped. It shows a stormy cloud band in the southern hemisphere.

You can get a sense of the processing that Thomospoulos did by comparing this image with the raw photo. The original has almost no contrast, either in color or in contrast. By enhancing both Thomospoulos makes the violent nature of these large storms, thousands of miles in size, quite visible.

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A global map of Mars’ future mining regions

9:38 am

A global map of Mars' future mining regions
Click for labeled image.

Using data accumulated in the past decade from orbiters, scientists have now published a global map of Mars, showing the regions on the red planet where there are high concentrations of hydrated minerals, minerals formed in the past in conjunction with the presence of water.

The maps to the right show those regions in various colors, indicating different types of minerals.

On Earth, clays form when water interacts with rocks, with different conditions giving rise to different types of clays. For example, clay minerals such as smectite and vermiculite form when relatively small amounts of water interact with the rock and so retain mostly the same chemical elements as the original volcanic rocks. In the case of smectite and vermiculite those elements are iron and magnesium. When the amount of water is relatively high, the rocks can be altered more. Soluble elements tend to be carried away leaving behind aluminium-rich clays such as kaolin.

The big surprise is the prevalence of these minerals. Ten years ago, planetary scientists knew of around 1000 outcrops on Mars. This made them interesting as geological oddities. However, the new map has reversed the situation, revealing hundreds of thousands of such areas in the oldest parts of the planet.

Though this data once again suggests that liquid water once flowed on the surface of Mars, for future colonists it is more important in that it identifies the regions where the most valuable resources will likely be found. For example, most of the colored regions on the map are located in the dry equatorial parts of Mars. However, south of the giant canyon Valles Marineris is a mineral region at about 30 to 40 degrees south latitude, to the northwest of Argyre Basin. This is also a region with a high concentration of glacial features. The two combined will likely make this region very valuable real estate.

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August 22, 2022 Quick space links

11:03 am

From BtB’s stringer Jay:

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Another Webb infrared image of Jupiter released

8:53 am

Jupiter as seen in the infrared by Webb
Click for original image.

The science team for the James Webb Space Telescope today released another infrared false-color image of Jupiter, this time processed for science instead of calibration of the telescope after launch.

That image is to the right, reduced to post here. From the caption:

Several exposures in three different filters were assembled to create this mosaic, after being corrected for the rotation of the planet. The combination of filters yields an image whose colors denote the height of the clouds and the intensity of auroral emissions.

The F360M filter (mapped to the red-orange colors) is sensitive to light reflected from the lower clouds and upper hazes. The red features in the polar regions are auroral emissions, caused by ions excited through collisions with charged particles at altitudes up to 1000 km above the cloud level. Auroral emission in red is evident in the northern and southern polar regions and reaches high above the limb of the planet. In the F212N filter (mapped to yellow-green colors), the gaseous methane in Jupiter’s atmosphere absorbs light; the greenish areas around the polar regions come from stratospheric hazes 100-200 km above the cloud level. The stratospheric haze that appears green in this composite is also concentrated in the polar regions, but extends down to equatorial latitudes and can also be seen along the limbs (edges) of the planet. The cyan channel holds the F150W2 filter, which is primarily sensitive to reflected light from the Jupiter’s deeper main cloud level at about one bar.

The Great Red Spot, the hazy equatorial region and myriad small storm systems appear white (or reddish-white) in this false-color image. Regions with little cloud cover appear as dark ribbons north of the equatorial region. Some dark regions — for example, those next to the Great Red Spot and in cyclonic features in the southern hemisphere — are also dark-colored when observed in visible wavelengths.

This image is part of the telescope’s early release science program.

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Ingenuity gearing up for 30th flight

10:33 am

The engineering team for the Ingenuity helicopter on Mars announced yesterday that they have successfully completed two some spin-up tests and are preparing for the first short hop following the pause in flights during the height of the Martian winter dust season.

To confirm that she is still flightworthy, we performed a 50-rpm spin on Aug. 6, and on Aug. 15 we performed a high-speed spin, which spun up the rotor system to flight-like speeds of 2,573 rpm for several seconds. Telemetry downlinked after both tests indicates Ingenuity is a go for flight.

Our 30th flight will be similar to our second flight. On April 22, 2021, Flight 2 was the first to include sideways movement: We “translated” 13 feet (4 meters) and then returned before landing. Flight 30 will be shorter, translating sideways only 7 feet (2 meters) and then landing, but with the specific goal of providing a data point on Ingenuity’s ability to accurately approach a landing target. Our navigation system’s performance will be of value to the Sample Recovery Helicopter team (part of the Mars Sample Return Program) in their early design work for a next-generation Mars Helicopter navigation system.

The last sentence references the recent decision to use a helicopter on the future sample return mission to land near the cached Perseverance samples and grab them.

The 30th flight is supposed to occur sometime in the next few days.

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Strings in Perseverance’s drill?

12:01 pm

String in Perseverance's drill
Click for full image.

Since August 5th, the Perseverance science team has been trying to figure out the origin as well as the consequences of “two string-like pieces” of foreign object debris (FOD as used by today’s acronym-happy scientists) that they have spotted next to one of the rover’s coring drill bits.

The photo to the right, cropped and reduced to post here, looks directly down at that core drill bit and shows one of those strings both to the side of the bit as well in full resolution in the inset. From today’s update:

Since first identified Aug. 5 in imagery of the rover’s sample collection system after a 12th rock core sample was taken, the FOD has been the focus of several methodical diagnostic activities in an attempt to better understand the nature of the debris.

We’ve commanded the rover to move, rotate, or vibrate components we think could harbor FOD. And we’ve obtained multiple sets of images of the components from different angles and in different lighting conditions from rover cameras: Mastcam-Z, Navcam, Hazcam, Supercam, and even the WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) camera located on the rover’s turret. Finally, a thorough review of recent coring and bit-exchange activities confirm that they all executed nominally with no indication of interference from the FOD.

Analysis of the latest round of imaging, downlinked earlier today, indicates that while the two small pieces remain visible in the upper part of the drill chuck, no new FOD has been observed. In addition, imagery taken of the ground beneath the robotic arm and turret, as well as the rover deck, also showed no new FOD.

Because these strings do not appear to interfere in any way with the drill’s operation, the science team has decided neither is a cause for concern, and will therefore command the rover to leave this just-completed drill site and move on to the southwest to a location at the base of the delta the rover visited about three months ago.

The strings themselves are likely pieces from the equipment released during the rover’s landing, and might even have come from the tangled string the rover imaged on the nearby ground in July, and that was gone just four days later. The wind had blown it away, and may have even at that time blown pieces into the drill.

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A “What the heck!?” crater on Mars

3:16 pm

A
Click for full image.

Today’s cool image falls into what I call my “What the heck?” category. The photo to the right, cropped and reduced to post here, was taken on May 31, 2022 by the high resolution camera on Mars Reconnaissance Orbiter. It was also picked by the science team as that camera’s picture of the day on July 12, 2022. From the caption:

This seems to belong to a class of craters in the Cerberus Plains that was flooded by lava, which was subsequently uplifted and fractured by an unknown process. This class of filled, uplifted and fractured craters is informally called “the waffle.” A combination of volcanic and periglacial processes seems possible.

In other words, the scientists only have a vague idea what created the broken up floor of this crater. For example, why did only the material in the interior of the crater get uplifted and fractured? Did this uplift occur before, during, or after the lava event?

The overview map below tells us a little about where that lava came from, and when.
» Read more

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Universe’s most massive star is found to be less massive than previously believed

2:18 pm

The uncertainty of science: Using data from the Gemini South telescope in Chile, astronomers have determined that the universe’s most massive star, dubbed R136a1, is actually less massive than previously believed.

By pushing the capabilities of the Zorro instrument on the Gemini South telescope of the International Gemini Observatory, operated by NSF’s NOIRLab, astronomers have obtained the sharpest-ever image of R136a1 — the most massive known star. This colossal star is a member of the R136 star cluster, which lies about 160,000 light-years from Earth in the center of the Tarantula Nebula in the Large Magellanic Cloud, a dwarf companion galaxy of the Milky Way.

Previous observations suggested that R136a1 had a mass somewhere between 250 to 320 times the mass of the Sun. The new Zorro observations, however, indicate that this giant star may be only 170 to 230 times the mass of the Sun. Even with this lower estimate, R136a1 still qualifies as the most massive known star.

What astronomers are trying to figure out is the highest possible mass a star can possibly have. This new data suggests that this upper limit is smaller than previously believed.

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Get above 30 degrees latitude on Mars and you can find ice everywhere

1:23 pm

Global overview of Mars' ice features

Glacial features inside a Mars crater
Click for full image.

Today’s cool image provides further proof that there is ample near surface ice almost anywhere on Mars once you get above 30 degrees latitude, in either the northern or southern hemispheres. The photo to the right, rotated, cropped, reduced, and annotated to post here, was taken on May 26, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the interior slope of an unnamed 15-mile-wide crater that sits inside the much larger 185-mile-wide Newton crater, located in the cratered southern highlands of Mars.

The black cross on the global map of Mars above marks the location of this crater.

The photo was taken as part of the routine monitoring planetary scientists are doing of the gullies that flow down this crater’s interior rim, a monitoring program that goes back to 2007. It is thought that those gullies might be created by seasonal frost, either water ice or dry ice, that causes erosion.

What struck me about the photo however was the glacial features on the floor of the crater. Near the bottom of the interior slope those features look broken up, as if the pressure from above pushed the ice sheets apart. Farther from the interior slope the features more resemble a typical glacial flow, slowly inching downward toward the crater’s low spot. All these glacial features also lend weight to the theory that water ice somehow caused or contributed to the formation of those gullies.

The global map above shows that this crater, while well within the 30 to 60 degrees mid-latitude band where many Martian glaciers are found, is also far from the many regions on Mars that scientists have mapped as having high concentrations of glaciers. And yet, the glacial features are here as well.

Near surface ice will not be found at every spot on Mars. However, once you get above 30 degrees latitude, the evidence increasingly suggests that you won’t have to go far or dig down deep to find it.

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A detailed description of Rocket Lab’s private Venus mission

10:00 am

Planned insertion of Rocket Lab's probe into Venus's atmosphere
Click for full figure.

Capitalism in space: In partnership with scientists at MIT, the Planetary Science Institute, and others, Rocket Lab engineers this week published a detailed description of the company’s planned privately funded mission to Venus, presently targeting a launch in May 2023.

From the paper’s abstract:

The Rocket Lab mission to Venus is a small direct entry probe planned for baseline launch in May 2023 with accommodation for a single ~1 kg instrument. A backup launch window is available in January 2025. The probe mission will spend about 5 min in the Venus cloud layers at 48–60 km altitude above the surface and collect in situ measurements. We have chosen a low-mass, low-cost autofluorescing nephelometer to search for organic molecules in the cloud particles and constrain the particle composition.

The figure above is figure 6 from the paper. It shows the probe’s planned path through Venus’s atmosphere. If the mission launches in May ’23 the probe would enter the atmosphere in October ’23.

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Samples from Ryugu prove the truly delicate and long-lived nature of the rubble-pile asteroid

9:27 am

Two new studies of samples brought back from the rubble-pile asteroid Ryugu by the Japanese probe Hayabusa-2 have found that the asteroid not only was never heated above 86 degrees Fahrenheit, it also contained dust grains older than the solar system itself.

The evidence from the first study, completed by Japanese scientists, suggested that:

  • 1.Asteroid Ryugu accreted some components that originated in the outer Solar System and contained abundant water and organics. The asteroid then traveled to the inner Solar System.
  • 2.Organics associated with coarse-grained phyllosilicates may serve as one of the potential sources of water and organics to the Earth.

The second study, using samples provided to American scientists, found two tiny dust grains that must have come from the material that existed before the formation of our solar system.

The team detected all the previously known types of presolar grains—including one surprise, a silicate that is easily destroyed by chemical processing that is expected to have occurred on the asteroid’s parent body. It was found in a less-chemically-altered fragment that likely shielded it from such activity.

This is not the first discovery of presolar grains, but their delicate existence in Ryugu confirms the conclusions of the first study, that Ryugu had to have formed in the outer solar system and then migrated inward over eons.

The second study also reviewed the make-up of the sample and concluded that Ryugu appears to most closely match the family of carbonaceous Ivuna-type (CI) chondrites, thought to be among the most primitive asteroids known, of which very few have been studied because of they rarely survive the journey through the Earth’s atmosphere.

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Astrobotic makes bid to buy assets of bankrupt Masten

9:02 am

Capitalism in space: Astrobotic, a startup focused on building lunar and planetary unmanned landers, has now made a formal bid to buy the remaining assets of Masten Space Systems, which had also been a startup focused on planetary missions but recently went bankrupt.

In a filing with the U.S. Bankruptcy Court for Delaware Aug. 14, Masten said it received a “stalking horse” bid of $4.2 million for Masten’s assets, including a SpaceX launch credit worth $14 million, from Astrobotic. The agreement, in effect, sets a minimum price for the sale of those assets but does not prevent Masten from seeking higher bids through an auction process that runs through early September.

The agreement appears to supersede an earlier agreement between Masten and a third lunar lander company, Intuitive Machines, included in Masten’s Chapter 11 filing July 28. That agreement covered the SpaceX launch credits alone and Masten did not disclose the value of it in its original filing.

Masten’s long term specialty has been vertical take-off and landing, something it has successfully done for the last several years on suborbital flights. This technology would be of great value to both Astrobotic and Intuitive Machines in developing their own first lunar landers.

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InSight’s power status continues to hold steady on Mars

11:21 pm

InSight power status through August 14, 2022

According to a new status update posted today by the science team, the power status for the Mars InSight lander continues to hold steady.

The graph to the right adds the new data, showing that the daily watt hours of power produced each day continues to hold at 400, while the dust in the atmosphere continues to drop towards its normal level of between 0.6 and 0.7 tau during the non-dust seasons.

These new numbers appear to be generally good news. Even though the dust continues to settle out of the atmosphere, it does not appear to be adding dust on the solar panels that would reduce their capability to generate power. Though the science team had predicted that the power levels would cause the mission to end sometime in August, at 400 watts per hour InSight has apparently continued to generate enough electricity to keep its seismometer running for at least another week.

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August 16, 2022 Quick space links

2:06 pm

Tiangong-3 in orbit
Click to see full image.

Some quickie stories worth noting, most provided by stringer Jay:

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Jupiter’s internal structure, based on Juno data

12:05 pm

Jupiter's internal structure
Click for original figure.

Scientists using Juno data of Jupiter’s magnetic field, combined with computer modeling, have now produced a rough map of the gas giant’s internal structure.

The image to the right, figure 2, of their paper, shows that structure. I have annotated the figure to provide some sense of scale. The bold violet line indicates their conclusions about the size of the dynamo that drives Jupiter’s powerful magnetic field, comprising more than 80 percent of the planet’s internal diameter. From the caption:

The gray area depicts the core (0.2 RJ) and the possible dilute core region. The violet area between the dotted lines (0.68 and 0.84 RJ) depicts the [hydrogen-helium] phase separated layer. The top dotted line at 0.95 RJ depicts the depth where the jets decay down to the minimum. The arrows represent possible convection area with unknown origin depth.

While this is a good first hypothesis based on the available data, that data remains quite sparse and uncertain. Thus, the conclusions here must be taken with a great deal of skepticism.

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More evidence of recent active volcanism on Venus

11:37 am

In a just published paper, scientists using archive data from the Magellan radar orbiter that circled Venus from 1990 to 1994, combined with data from Europe’s Venus Express that orbited from 2006 to 2015, have detected more evidence of recent volcanic activity in a canyon dubbed Ganis Chasma located in a rift zone called Atla Regio.

From the paper’s conclusion:

The pattern of the radar emissivity in these regions is consistent with relatively young and unweathered materials. The transient IR-bright spots in these regions detected 20 years after Magellan, provide independent corroboration of active volcanism in Ganis Chasma since the 1990’s.

As a possible site of current tectonic and volcanic activity, Atla Regio represents one important science target for the upcoming missions to Venus.

There are presently four missions planned for Venus, Europe’s EnVision orbiter, NASA’s VERITAS and DAVINCI+ probes, and Russia’s Venera-D missoin. All will certainly take a closer look at this region to see if there is active volcanism going on there now.

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Dust and clouds in the Martian atmosphere, as seen by UAE’s Al-Amal orbiter

11:18 am

Two new science papers have just been released detailing results from the Al-Amal (Hope) Mars orbiter that was designed and built by American universities for the United Arab Emirates (UAE).

Both papers used data obtained from the orbiter’s infrared spectrometer, dubbed the Emirates Mars Infrared Spectrometer (EMIRS).

Daily cloud cover changes on Mars
Figure 1 from paper. Click for full image.

First, the instrument tracked the daily changes in the planet’s cloud cover.

A prominent region of clouds that is commonly observed near the equator during Mars’ cold season—known as the aphelion cloud belt—was observed to reach a minimum near midday, with more clouds typically observed in both the morning and afternoon. Distinct differences were found in clouds observed near volcanoes, which tended to reach a minimum before local noon and increase throughout the afternoon.

The figure to the right shows this. In the morning and afternoon (LTST’s 7 and 17), there is a high concentration of clouds in the equatorial region above the Tharsis Bulge where the highest Martian volcanoes are located. During the middle of the day (LTSTs 11 and 13) this cloud cover largely dissipates, with a corresponding increase in cloud cover in Hellas Basin, in the southern hemisphere.

The second paper took a more general look at the data, including the change in temperature depending on elevation as well as dust and water content during the Martian northern spring and summer. From the abstract:
» Read more

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Cones south of Starship’s prime landing sites on Mars

3:55 pm

Cones near Phlegra Mountains
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on May 7, 2022 by the high resolution camera on Mars Reconnaissnace Orbiter (MRO). It shows what the scientists have labeled as “Cones in Phlegra.”

Cones such as these are one of the prime geological mysteries of Mars’ northern lowland plains. Scientists do not know yet whether they are either mud or lava volcanoes, or even if they are sedimentary mesas that resisted subsequent erosion. In fact, it was hoped by some American scientists that the Chinese would send its Zhurong rover north towards a nearby cone to find out, but alas, the Chinese decided to head south instead.

Zhurong however was on the other side of Mars. The overview map below shows us where these cones are located.
» Read more

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A distant cliff and a rocky path forward

11:11 am

Mosaic of Gediz Vallis
Click for full image.

Close-up of distant cliff face
Click for full image.

Two cool images arrived today from Curiosity, as it is about to enter the Martian canyon of Gediz Vallis. The mosaic above, cropped, reduced, and annotated to post here, was assembled from photos taken by the rover’s right navigation camera on August 15, 2022. The photo to the right, cropped and reduced to post here, was taken the same day by the rover’s Chemistry camera, normally designed to take very close-up pictures of nearby features. In this case the science team aimed it at a distant cliff face, marked by the arrow in the panorama above, to get a preview of some of the many layers in that mesa.

And has become quite expected from Mars, the number and types and variety of layers is astonishing. The layer that forms the flat bright area at the center of this image is what scientists have dubbed “the marker layer”, since they have found it at similar elevations in many places on the flanks of Mount Sharp. (See the annotated overview map from a post last week.)

Curiosity’s planned route is to head to the right of this mesa, circling around it to get into the upper reaches of Gediz Vallis. First however engineers are going to have to figure out how to get the rover past the somewhat large scattered rocks on the ground directly ahead, without further damaging Curiosity’s already tattered wheels. At first glance there does not appear to be any clear path.

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Curiosity finally looks out into Gediz Vallis

12:56 pm

First look into Gediz Vallis
Click to view full mosaic.

Overview map
Click for interactive map.

Cool image time! Curiosity’s right navigation camera today produced the mosaic above, cropped and reduced to post here, taking its first good look into Gediz Vallis, the canyon that the rover has been aiming for since it landed on Mars ten years ago.

The green dot on the overview map to the right marks the approximate location of a recurring slope lineae, a streak that comes and goes depending on the seasons whose cause remains uncertain. The yellow lines show the approximate area covered by the mosaic. The red dotted lines show Curiosity’s upcoming route. According to previously announced plans, the rover will not head straight into Gediz Vallis, but circle to the west or right of the mesa to the right of Kukenan.

The valley of course looks spectacular. For scale, the cliff face of Kukenan is estimated to be about 1,500 feet high.

The most important revelation from this image however is the ground terrain. It looks like Curiosity will have no problem moving forward into the canyon from this point, something the science team could not know for sure until the rover reached the saddle and could look down and actually see ahead.

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InSight seismometer data suggests no underground ice at landing site

9:25 am

Using a computer model combined with seismometer data gathered by the Mars lander InSight, scientists have concluded that there is little or no underground ice in the equatorial region where InSight sits.

From the paper’s abstract:

We use rock physics models to infer cement properties from seismic velocities. Model results confirm that the upper 300 m of Mars beneath InSight is most likely composed of sediments and fractured basalts. Grains within sediment layers are unlikely to be cemented by ice or other mineral cements. Hence, any existing cements are nodular or formed away from grain contacts. Fractures within the basalt layers could be filled with gas, 2% mineral cement and 98% gas, and no more than 20% ice. Thus, no ice- or liquid water-saturated layers likely exist within the upper 300 m beneath InSight. Any past cement at grain contacts has likely been broken by impacts or marsquakes.

As the lander sits just north of the equator in the red planet’s equatorial zone, which ample orbital data has suggested is a dry region (as shown in the global map below), this result is not a surprise. It does provide further confirmation however of this conclusion, that if there is any water on Mars within 30 degrees latitude of the equator, it will be deep underground, and likely only in certain regions.
» Read more

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A typical Martian rock on Mount Sharp

10:03 am

Panorama of pass
Click for full 360 degree panorama.

Typical Martian rock
Click for full image.

Cool image time! The photo to right, taken by the Mars rover Curiosity on August 9, 2022, provides a nice close-up of what might be a somewhat typical rock on the flanks of Mount Sharp in Gale Crater, many layered with some of those layers extending outward to the side for somewhat ridiculous distances as thin flakes.

The scientists call it a float rock, because they think it actually fell from the cliff dubbed Bolivar in the panorama above. Thus, it gives geologists data on the layers higher up that are not easily accessible from Curiosity’s present position.

The panorama is a mosaic created from images taken by the rover’s right navigation camera on August 8, 2022. The white arrow marks the rock. The green dot marks the approximate location on the cliff face of a previously observed recurring slope lineae, streaks that appear to come and go seasonally whose origin is still not understood.

The red dots mark my guess as to the route engineers will pick for Curiosity as it weaves its way around the other float rocks ahead.
» Read more

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Fractures in the Martian northern lowland plains

1:35 pm

Fractures in the northern lowland plains
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on April 21, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) of a spot in the Martian northern lowland plains.

Generally the surface of these lowland plains — especially at high latitudes above 30 degrees — tends to appear very water saturated, producing blobby features and what look like mud volcanoes. This picture however features something different, what the scientists have labeled fractures, geological features that appeared caused by dry conditions and sudden quake-like events. The break in the fracture near the top of the photo illustrates why water flow had little if anything to do with its formation. Other fractures in the full image show the same thing. Also the stippled surface along the picture’s right edge also suggest there is little near surface water or ice at this location.

The location, as shown by the overview map below, suggests that water might still have played a part, but only a long time ago.
» Read more

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InSight’s power status holding steady on Mars

9:47 am

InSight's status as of August 9, 2022

Yesterday the InSight science team posted the lander’s ongoing power status, as it has been doing about every week since in June the team announced that they expected power to run out sometime in August, ending the mission.

I have created the graph to the right, showing the data from all those updates, to try to glean the overall trends. The red line indicates the tau level of dust in the atmosphere, essentially telling us how much that dust is blocking light from the Sun. Normally outside of dust season this number should range from 0.6 to 0.7. Since May 17 that dust level has been steadily declining, which thus increases the amount of sunlight reaching the panels.

The blue line marks the amount of power the lander’s panels have been able to produce. The lack of change in this line reveals both good and bad news. The good news is that the power level is holding steady, at a level that allows InSight’s one operating instrument, its seismometer, to continue to function. Should this power level continue to remain stable, that seismometer should be able to operate past August, thus extending the instrument’s life longer than expected.

The bad news is that the power levels are not going up as the dust level is dropping. This suggests that the dust layer on the panels that is preventing them from generating power is actually getting thicker. InSight has still not experienced any puff of Mars’ weak wind capable of blowing dust off those panels. Instead, as the dust settles out of the atmosphere with the end of dust season, some is settling on the panels themselves.

As new updates arrive I will update this graph. Stay tuned. InSight is not yet dead, though the vultures are unfortunately circling overhead.

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Mapping the break-up and impact of one of the first asteroid’s tracked from space to the ground

11:33 am

Computer simulation of asteroid break-up
Click for full figure.

By analyzing 600 scattered pieces recovered from a 20-foot wide asteroid that broke-up and landed in the Sudan in 2008, scientists have discovered that some surface pieces were able to reach the ground unscathed because they were on the asteroid’s protected aft as it plowed through the atmosphere.

This asteroid was one of the first ever discovered shortly before impact and then tracked as it hit the atmosphere and broke up, the pieces falling as meteorites. The image to the right, figure 4 of the paper, shows the computer simulation of the asteroid’s break-up, based on the data obtained by mapping the location of its pieces on the ground. From the press release:

“Because of the high speed coming in, we found that the asteroid punched a near vacuum wake in the atmosphere,” says Robertson. “The first fragments came from the sides of the asteroid and tended to move into that wake, where they mixed and fell to the ground with low relative speeds.”

While falling to the ground, the smallest meteorites were soon stopped by friction with the atmosphere, falling close to the breakup point, while larger meteorites were harder to stop and fell further downrange. As a result, most recovered meteorites were found along a narrow 1-km wide strip in the asteroid’s path. “The asteroid melted more and more at the front until the surviving part at the back and bottom-back of the asteroid reached a point where it suddenly collapsed and broke into many pieces,” said Robertson. “The bottom-back surviving as long as it did was because of the shape of the asteroid.”

No longer trapped by the shock from the asteroid itself, the shocks from the individual pieces now repulsed them, sending these final fragments flying outwards with much higher relative speed. “The largest meteorites from 2008 TC3 were spread wider than the small ones, which means that they originated from this final collapse,” said Jenniskens. “Based on where they were found, we concluded that these pieces stayed relatively large all the way to the ground.”

The location of the large meteorites on the ground still reflects their location in the back and bottom-back part of the original asteroid.

While there is a certain randomness in how any asteroid breaks up, this data will help scientists better understand the make-up of future meteorites they find. The bigger more widely scattered pieces likely came from the asteroid’s rear surface.

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Further damage to Curiosity’s wheels

10:14 am

Curiosity wheel comparison of damage
For the original images, click here for the top photo and here and here
for the bottom photo.

The photo comparison to the right, created from high resolution images taken by Curiosity on Mars two months apart, provides us a new update on the state of the rover’s damaged wheels. It shows damage on the same wheel that I have been tracking for several years.

The numbers indicate the same treads, or grousers as termed by the science team. The “+” sign indicates spots where new damage has occurred since the previous photo.

The top photo was taken on June 3, 2022, and was the first to show new damage in more than five years. The bottom photo was taken on August 6, 2022, and shows that another small piece on the same grouser has broken off during the past two months.

Other than this change, however, the rest of the grousers appear unchanged. Moreover, a comparison with an earlier image of this same wheel taken in the summer of 2021 shows that grouser #6 as well as the unnumbered one just below appear also unchanged.

The damage in grouser #5 however is still concerning, and reflects the increasing roughness of the terrain as Curiosity climbs higher and higher on Mount Sharp. Though the science team has been very careful since the rover’s first few years on Mars to travel around obstacles that could damage the wheels, it apparently is becoming harder to do so.

However, even if this wheel eventually loses all the metal between the zig-zag grouser treads, the science team has said it has “proven through ground testing that we can safely drive on the wheel rims if necessary.” The team as also said they do not think that is likely, at least not for a long time, and based on the rate of damage documented by these pictures, this appears very true.

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Strange terrain southwest of Jezero Crater

1:17 pm

Strange terrain near Jezero Crater

Cool image time! The photo to the right, cropped and reduced to post here, was taken on June 16, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists have merely label “landforms.”

I instead call them strange. Clearly we are seeing exposed layering that surrounds the mesa in the middle of the image. This in turn suggests that the mesa top was once the surface of this whole region, and that region had been formed by the repeated placement of multiple sedimentary layers. Then, over time the surrounding terrain was eroded away, exposing those underlying layers.

Even so, some of the parallel lines do not appear to be layers, but striations etched into the ground. To get a better look, the white box marks the area covered by a full resolution close-up below.
» Read more

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