Tag: science

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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Curiosity celebrates ten years on Mars

9:31 am

Curiosity's location in Gale Crater

Sometime today the rover Curiosity will celebrate its tenth anniversary on Mars. The oblique graphic of Gale Crater above, first released by the science team shortly before landing in 2012, has been further annotated with a red line to show the rover’s journey since then. As noted by Scott VanBommel, Planetary Scientist at Washington University, today on the science team’s blog:

As we the science and engineering teams have aged this last decade, so has Curiosity. The toll of ten years and nearly 28.5 km [17.7 miles] of Mars driving shows with every MAHLI wheel imaging activity, with less energy available for a plan, and with aging mechanisms. This is the life of a Mars rover. Spirit and Opportunity were no different, yet they persisted and paved the way scientifically and technologically for the rovers of today. Curiosity has made numerous scientific discoveries during these ten years, emphasized by the over 500 science team publications, with many more ahead as we continue our ascent and exploration of Gale crater and Mount Sharp.

I look forward to the next ten years.

Despite that aging, Curiosity’s general condition appears quite excellent, with its wheels the greatest concern but generally holding up. Based on the last ten years, the rover is likely to remain operational for at least ten more years, if not longer.

In the more immediate future, the rover is only days away from getting its first good look down into Gediz Valles, that canyon on the graphic above that it has been traveling towards since day one.

A good review of five of Curiosity’s biggest discoveries using its sample analysis instrument can be found here.

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SpaceX launches South Korea’s Danuri lunar orbiter

4:50 pm

SpaceX today successfully launched South Korea’s Danuri lunar orbiter, also called the Korea Pathfinder Lunar Orbiter.

The first stage completed its sixth flight, landing on a drone ship in the Atlantic. The fairings completed their fourth flight.

Danuri is now on its way to the Moon, with a planned arrival in lunar orbit on December 16, 2022. It carries six instruments, one of which was developed by NASA. The spacecraft, while designed to study the Moon, is primarily a technology test mission laying the groundwork for more sophisticated interplanetary South Korean missions. More information about the mission can be found here.

The leaders in the 2022 launch race:

34 SpaceX
28 China
10 Russia
6 Rocket Lab
5 ULA

The U.S. now leads China 49 to 28 in the national rankings, and the entire world combined 49 to 45. With this launch American private enterprise has now surpassed the entire launch total for all of 2021, and has the most launches for the U.S. since 1967, when it completed successfully 57 launches.

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Glacial flows pushing out through a Martian crater rim

12:51 pm

Wider view of 6-mile-wide crater
Click for full image.

Today’s cool image once again illustrates how Mars is far from a waterless planet. Instead, there is strong evidence that water ice can be found across most of the Red Planet’s surface, excluding the equatorial regions lower than 30 degrees latitude.

The photo to the right was taken on September 11, 2021 by the wide view context camera on Mars Reconnaissance Orbiter (MRO). It shows a 6-mile-wide unnamed crater on Mars, located at 35 degrees south latitude, with what appears to be a glacier in its interior, flowing to the southwest towards several breaches in the crater’s southwest rim. Several of those breaches now sit higher than the flow, suggesting that the glacier itself was once higher and flowed out of those gaps. Now the level has dropped, and the only place the glacier exits the crater is the central gap at the center of the white rectangle.

That white rectangle marks the area covered by a recent MRO high resolution image, taken on March 29, 2022 and cropped and reduced to post below.
» Read more

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Lucy science team ends attempt to deploy solar array

9:12 am

Lucy's planned journey
Lucy’s planned mission, the yellow dot indicating approximately
its present position. Click for full image.

The Lucy science team has decided to end further attempts to fully deploy one of the spacecraft’s two solar arrays, leaving it just short of fully deployed.

On seven occasions in May and June, the team commanded the spacecraft to simultaneously run the primary and backup solar array deployment motors. The effort succeeded, pulling in the lanyard, and further opening and tensioning the array.

The mission now estimates that Lucy’s solar array is between 353 degrees and 357 degrees open (out of 360 total degrees for a fully deployed array). While the array is not fully latched, it is under substantially more tension, making it stable enough for the spacecraft to operate as needed for mission operations.

The press release announcing this decision is horribly written. First, it buries this decision to the release’s last three paragraphs so that it can rave about the brilliance of Lucy’s engineers and scientists in solving the overall problem. Second, it never actually states that this is the decision that has been made. It implies it.

Regardless, it appears the engineers are satisfied that the almost fully deployed array will hold its position for the rest of the mission. They have decided that the risk of trying to fully deploy it is greater than the risk of having it slightly open.

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The scattered debris from Perseverance’s landing, now being tracked by the rover

10:51 am

Perseverance's parachute, as photographed by Ingenuity
Click for full image.

A piece of string on Mars
Click for full image.

The Perseverance science team today posted a detailed update on the various pieces of debris that both the rover and the Ingenuity helicopter have been tracking since both landed on Mars in February 2021.

Some of the EDL [entry, descent, landing] hardware broke into smaller pieces when it impacted the surface. These pieces of EDL debris have been spotted in images of the Hogwallow Flats region, a location roughly 2 km to the northwest of the EDL hardware crash zones. As of Sol 508 (July 24, 2022), the operations team has catalogued roughly half a dozen pieces of suspected EDL debris in this area. Some of these EDL debris are actively blowing around in the wind. So far, we’ve seen shiny pieces of thermal blanket material, Dacron netting material that is also used in thermal blankets, and a stringlike material that we conclude to be a likely piece of shredded Dacron netting.

To the right are two of the most interesting examples. The top image shows the parachute and associated equipment from the landing, taken by Ingenuity during a flight in April 2022. That image, when compared with an earlier picture taken from orbit, showed that the wind of Mars, though incredibly weak, had been able to shift the parachutes edges.

The second image shows the string that the rover photographed on July 12, 2022, and had blown away four days later when Perseverance re-photographed this site.

Today’s update notes that the area in the crater they have dubbed Hogwallow Flats “appears to be a natural collecting point for windblown EDL debris.” The flats are an area at the foot of the delta that flowed into Jezero Crater in the past, and is an area where Perseverance has been traveling most recently.

That the wind has been able to move small pieces so effectively is I think somewhat of a surprise. That it is gathering the material against the crater’s western cliffs suggests the prevailing winds here blow to the west.

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500 healthcare workers, fired for refusing COVID jab, win $10.3 million lawsuit

1:53 pm

Victory!

Bring a gun to a knife fight: Because NorthShore University HealthSystem in Illinois refused in 2020 to give any employee a religious exemption from getting the COVID jab and thus fired 500 healthcare workers, those workers sued, and last week they won a $10.3 million settlement from the university.

As part of the settlement agreement, NorthShore will pay $10,337,500 to compensate hundreds of health care employees. NorthShore will also change its unlawful “no religious accommodations” policy to make it consistent with the law, and to provide religious accommodations in every position across its numerous facilities. No position in any NorthShore facility will be considered off limits to unvaccinated employees with approved religious exemptions.

In addition, employees who were terminated because of their religious refusal of the COVID shots will be eligible for rehire if they apply within 90 days of final settlement approval by the court, and they will retain their previous seniority level.

The non-profit law firm that brought the case, Liberty Counsel, is taking a 20% cut of this class action, rather than the traditional 33% cut. As for the 500 fired workers:
» Read more

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Curiosity heads into the pass

10:16 am

Mosaic by Curiosity
Click for full mosaic.

Overview map
Click for interactive map.

Cool image time! The mosaic above, cropped, reduced, and annotated to post here, was created from 31 navigation images taken by the Mars rover Curiosity, and shows the rover’s upcoming drive. From the science team’s July 29, 2022 update:

We are attempting to reach a high point, just at the top right edge of the image, so we can look down into the valley to see if there is a way out on the other side and to help plan our path forward. High tilts, sand, and large and small rocks clutter the terrain, requiring the Rover Planners to pick their way around while making sure they stay clear of the hazards.

After the drive, we took a lot of imaging from our new location, including a 360 degree Mastcam mosaic and an upper tier of imaging to catch the tall relief of the valley walls.

The green dot in the image above as well as the overview map to the right indicates 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 blue dot on the map marks the rover’s position on August 1, 2022. The yellow lines indicate the approximate area covered by the mosaic above. The large red dots on the overview indicate the rover’s original planned route, with the smaller red dots indicating the hoped-for route to get back to that path.

In the far distance the upper slopes of Mount Sharp can faintly be seen through the winter dust haze. That mountain is about 18,000 feet high, though its actual peak is not yet visible. Curiosity is still about 16,000 feet below that peak. Kukenan is about 1,500 feet high. The cliff with the slope lineae is probably about 400-500 feet high The two side hills that delineate the pass ahead are probably no more than 200 feet high.

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First Webb infrared image of Cartwheel Galaxy

9:13 am

Webb's view of the Cartwheel Galaxy
Click for full image.

Scientists today have released a new infrared image of the Cartwheel Galaxy, taken by two instruments on the James Webb Space Telescope. That image is to the right, reduced to post here. From the caption:

In this near- and mid-infrared composite image, MIRI data are colored red while NIRCam data are colored blue, orange, and yellow. Amidst the red swirls of dust, there are many individual blue dots, which represent individual stars or pockets of star formation. NIRCam also defines the difference between the older star populations and dense dust in the core and the younger star populations outside of it.

The galaxy, located about a half billion light years away, is one of the more well known astronomical objects due to its unusual shape, believed caused by a collision with a smaller galaxy sometime in the past. Earlier this year for example astronomers discovered a supernovae had exploded in the galaxy sometime in 2021. To see a 1995 Hubble optical image, go here.

This Webb image reveals many new details previously obscured by dust.

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Sunspot update: Activity recovers mostly from last month’s decline

9:04 pm

It is the start of the month, and thus time to post NOAA’s monthly update of its graph tracking the number of sunspots on the Sun’s Earth-facing hemisphere. That graph is below, with some additional details added by me to provide a larger context.

After the first real decline in sunspot activity in June, the Sun recovered that decline almost completely in July. Though the ramp up to solar maximum has stalled somewhat in the last two months, the trend continues to point to a very active maximum, much higher than predicted as well as much stronger than the last very weak maximum in 2020.

» Read more

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Ice in the Martian equatorial region?

1:55 pm

Global overview of ice on Mars

Glacial features in low latitude Martian crater

Today’s cool image to the right, rotated, cropped, and reduced to post here, is actually an older captioned image, published in 2017 by the science team for the high resolution camera on Mars Reconnaissance Orbiter (MRO). I missed its significance when it was first released. From the caption by Alfred McEwen of the Lunar & Planetary Laboratory in Arizona:

The material on the floor of this crater appears to have flowed like ice, and contains pits that might result from sublimation of subsurface ice. The surface is entirely dust-covered today. There probably was ice here sometime in the past, but could it persist at some depth?

This crater is at latitude 26 degrees north, and near-surface ice at this latitude (rather than further toward one of the poles) could be a valuable resource for future human exploration.

As shown in the global map of Mars above, this 26-mile-wide unnamed crater, marked by the black cross, is well inside the equatorial region 30 degrees north and south from the equator where almost no evidence of near surface ice has been found. Whenever I look at an image from MRO, if the picture appears to show ice or glacial features, its latitude is always 30 degrees or higher. If it does not, it is almost always in this equatorial region.

This crater however shows evidence of glacial features in its interior, but is far closer to the equator than normal. How could this be? It is possible that its high altitude, sitting in the southern cratered highlands, might have helped preserve its buried but near surface glacial features.

Regardless, as McEwen notes, its location closer to the equator is tantalizing, because it suggests that such ice could exist even in the equatorial regions, though buried and thus not detected by the instruments presently available in Mars orbit.

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Inverted Martian tadpole

2:17 pm

Inverted Martian tadpole
Click for full image.

Cool image time! On Mars it is not unusual to see what scientists call tadpole features, craters with meandering canyons or channels either flowing into or out from the crater’s rim. The photo to the right, rotated, cropped, and reduced to post here, is another example, though with one major difference. The channel and crater are inverted, with the channel instead a ridge and the crater a circular plateau. The picture itself was taken on April 16, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

Orbital images have found on Mars a lot of what scientists call pedestal craters, where the impact packed and hardened the ground under the crater so that when the surrounding terrain eroded away the crater remained, as a plateau.

Scientists have also found on Mars a lot of what they call “inverted channels,” places where the channels of a drainage pattern followed the same geological process, becoming more resistant to erosion so that over time it turned from a channel to a ridge.

Here we have a combination of both. The overview map below provides us the larger picture.
» Read more

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Study: The Moon’s poles might not be the only places to find lunar water

1:03 pm

Global map of hydrogen abundances on Moon
Click for full image.

According to a new study published in June in the Journal of Geophysical Research: Planets, while the lunar poles might contain water ice in permanently shadowed craters — based on detected hydrogen abundances — there is an even higher concentration of hydrogen found in the Aristarchus Plateau region in the lower mid-latitudes.

The map to the right is figure 9 from the paper, annotated to post here, showing the Moon’s hydrogen abundances globally, with lighter areas having higher concentrations. The boxes indicate five lunar regions that appear to hold higher levels of hydrogen and thus might contain higher amounts of water. From the paper’s conclusions:

The bulk hydrogen map also led to the first identification of bulk hydrogen enhancements within a pyroclastic deposit (Aristarchus Plateau), an identification that corroborates previous suggestions that hydrogen was among the volatiles involved in the eruption and emplacement of pyroclastic deposits. Further, with the understanding that there are enhanced bulk hydrogen abundances within at least one pyroclastic deposit and not just a surface enhancement, this leads to the implication that the hydrogen contained within just the Aristarchus Plateau may represent a significant fraction of the hydrogen that exists in the Moon’s near-subsurface, including that at both lunar poles. [emphasis mine]

It is important to note that finding high hydrogen abundances does not automatically mean you have found water. For hydrogen to exist on the Moon the atom must be bound in a molecule, and usually water is chosen as the most likely candidate. In the case of Aristarchus, however, the paper instead suggests that hydrogen was placed there as pyroclastic deposits, when active volcanism was occurring a long time ago. While water ice might not be present now in these regions, the data also suggests that water played a major role in its formation.

These hydrogen abundances however also signal the faint possibility of that water ice might be buried here, below the surface, left over from those early volcanic processes. The data also suggests even if the hydrogen is bound in other materials, mining and processing might be able to extract water from it.

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The big storms at Jupiter’s poles are coherent and stable

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Storms on Jupiter
Click for full image.

After four years of observations by Juno in orbit around Jupiter, scientists studying the storms at the gas giant’s poles have found that those storms are stable, long-lasting features. From the abstract of their paper:

These data have shown cyclones organized in snowflake-like structures. The Jupiter’s polar cyclones are long-lasting features, which did not disappear or merge during four years of observations.

The image to the right, posted by me earlier this week, shows several of these storms, or vortices, at Jupiter’s north pole. Previous work had documented the overall pattern, as described in the paper:

The observed vortices display geometrical symmetries around both poles: circumpolar cyclones (CPCs), organized in a regular pattern, surround a central one. At the north pole, eight circumpolar vortices form an octagonal structure, while at the south pole, five circumpolar vortices are arranged in a pentagonal pattern; both central polar vortices show some degree of displacements to the geometrical pole, about 0.5° for the Northern Polar Cyclone (NPC) and 1°-2° for the Southern Polar Cyclone (SPC).

While this research has found little change in these storms over four years, it is unknown what their long term evolution will be for an entire Jupiter year, twelve Earth years long.

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New paper: Glaciers on Mars could have been extensive, despite the lack of expected subsequent landforms

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glacial drainage patterns as expected on Mars
Click for full figure.

According to a new paper published this week, scientists now posit that glaciation could have been much more extensive in the geological history of Mars than presently believed, despite the lack of the expected subsequent landforms as seen on Earth.

From the abstract:

The lack of evidence for large-scale glacial landscapes on Mars has led to the belief that ancient glaciations had to be frozen to the ground. Here we propose that the fingerprints of Martian wet-based glaciation should be the remnants of the ice sheet drainage system instead of landforms generally associated with terrestrial ice sheets. We use the terrestrial glacial hydrology framework to interrogate how the Martian surface gravity affects glacial hydrology, ice sliding, and glacial erosion. …[W]e compare the theoretical behavior of identical ice sheets on Mars and Earth and show that, whereas on Earth glacial drainage is predominantly inefficient, enhancing ice sliding and erosion, on Mars the lower gravity favors the formation of efficient subglacial drainage. The apparent lack of large-scale glacial fingerprints on Mars, such as drumlins or lineations, is to be expected. [emphasis mine]

In other words, on Earth the higher gravity causes glaciers and ice sheets to slide, with the liquid water at the base acting as a lubricant. On Mars, the lower gravity slows that slide, so that the water at the glacier’s base drains away instead, causing erosion and the formation of a drainage pattern in the ground beneath the glacier or ice sheet.

The image above, from figure 1 of the paper, shows on the left a graphic of the two types of drainage patterns expected, and on the right two examples found on Earth (D1: Devon Island; D2: Northwest Territories). Orbiter images of Mars have found variations of these types of drainage patterns in numerous places in Mars’ mid-latitude glacial bands, as shown below.
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NASA/ESA revise plan to recover Perseverance core samples from Mars

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NASA and ESA yesterday announced that the agencies have revised their plan to recover Perseverance core samples from Mars, dropping the launch of a rover to pick up the samples.

Instead, they have decided to use Perseverance to bring the samples to the return vehicle, which will also carry two small helicopters.

In 2030, if all goes as planned, the NASA lander will touch down near where Perseverance is working. The rover will drive over to the lander, and an ESA-built robot arm will extract the tubes one by one and place them inside a spherical container the size of a basketball. In early 2031, a rocket on the lander will loft the container into Mars orbit, where a return craft built by ESA will snare it, enclose it in several layers of shielding for safety, and then head for home. In 2033, a saucer-shaped descent pod will carry the samples down to the Utah desert.

If Perseverance gets into difficulties during its 9-year wait for company, controllers can instruct it to drop its cargo of sample tubes onto the ground, creating a second depot. If that happens, the helicopters come into play: they can fly up to 700 meters, land next to a sample tube—each weighs up to 150 grams—and, with wheels on the bottom their feet, roll over the tube and pick it up with a grabber. On returning to the lander, they will drop the tubes on the ground for the arm to pick up.

The change means that the rover the United Kingdom was planning to build will either be abandoned, or repurposed as a lunar rover.

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A Martian slot canyon!

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A Martian slot canyon
For originals go here, here, and here.

Overview map
Click for interactive map.

Cool image time! The mosaic to the right is made up of three images produced by the high resolution camera on the Mars rover Perseverance (found here, here, and here). All three were taken on July 24, 2022 and look north to the nearest cliff face at the head of the large delta that flowed into Jezero Crater some time in the distant past.

The rover was about 80 feet away from the feature when the photo was snapped. Though scale in the photo is not provided, using the scale in the overview map below I would guess this slot canyon is several feet wide, with some spots narrow enough that your body would touch both walls at spots. Its height is likely nor more than 20 feet high, at the very most.

On the overview map, the blue dots mark Perseverance’s location, in both the main map and the inset. The green dot marks where the helicopter Ingenuity presently sits. The red dotted line is my guess as to the future route of the rover up into the delta. The yellow lines indicate the area viewed in the mosaic.

Though hardly as deep as the many slot canyons found in the American southwest, that this slot exists on Mars is quite intriguing. Did it form like those southwestern slots from water flow? Probably not. More likely we are looking at a fracture produced by shifts in the entire delta itself, and then later widened by wind.

That the cliff shows multiple layers suggests the delta was laid down in multiple events, and that the fracture occurred after the delta was emplaced. That the layers on either side of the fracture appear to match up strengthens this conclusion. These layers also suggest that the layering is not simply in a series of small events. The layers are also grouped into larger aggregates, suggesting those larger groupings mark longer epochs, each with its own unique conditions.

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