Tag: science

Ingenuity completes 32nd flight

10:21 am

According to a tweet from JPL, Ingenuity successfully completed its 32nd flight on Mars on September 18, 2022.

The 55.3-second flight covered 93.74m at a max speed of 4.75 meters per second.

That is about 308 feet distance, comparable to the helicopter’s previous flight. Though it probably continued to the west, as with that last flight, JPL’s tweet did not provide any directional information.

This second short hop in a row however suggests that the team’s focus has definitely shifted from scouting for Perseverance to practicing precision landings, thus gathering data to help build the future Martian helicopter that will be used to pick up Perseverance’s core samples some time in the future.

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Want to do a virtual hike in Jezero Crater on Mars? You can!

10:01 am

Using data from Mars orbiters, Perseverance, and Ingenuity, scientists have now created a virtual hiking map of Jezero Crater, allowing anyone to explore in detail the same places that the rover and helicopter have visited.

You can view the map here. From the press release:

The map allows virtual hikers to zoom in and out, and pan rapidly across scenes, so that they can explore the landscape from large scales down to centimetre-detail. Some of the 360° panoramas integrated with the waypoints have been synthetically rendered from orbital image data. Others are real panoramas stitched together from a multitude of single images taken by the Mastcam-Z camera instrument onboard the Mars 2020 Rover Perseverance, which have been provided by the University of Arizona. The sounds have been recorded by the SuperCam instrument on that same rover mission.

I’ve played with the map only a little, but find it quite amazing and useful, especially because it seems to work well on my relatively ordinary desktop Linux computer.

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Webb’s first infrared image of Neptune

9:30 am

Webb's infrared view of Neptune
Click for full image.

The science team for the James Webb Space Telescope today released that telescope’s first infrared image of Neptune.

That image is to the right, cropped and reduced slightly to post here. It is, as the press release touts, the best view in decades of Neptune’s rings. From the caption:

The most prominent features of Neptune’s atmosphere in this image are a series of bright patches in the planet’s southern hemisphere that represent high-altitude methane-ice clouds. More subtly, a thin line of brightness circling the planet’s equator could be a visual signature of global atmospheric circulation that powers Neptune’s winds and storms. Additionally, for the first time, Webb has teased out a continuous band of high-latitude clouds surrounding a previously-known vortex at Neptune’s southern pole.

The dots around the gas giant are the heat signatures of seven of its fourteen moons.

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InSight’s power level holding steady

9:57 pm

InSight's on-going power levels

The Energizer bunny of Mars, the InSight lander, continues to hold on. The engineering team tonight issued another status report, as shown in the graph to the right. For the past week the lander continued to produce 420 watt-hours per day, even though the tau level of dust in the atmosphere increased from 0.8 to 0.85.

The tau level of dust outside of the winter dust season is normally between 0.6 and 0.7. Even though Mars is moving out of winter, that level has increased slightly above InSight. And yet, even with a higher dust content and thus less sunlight, the lander’s dust-covered solar panels are generating power, at a very slightly higher level.

The InSight team had expected the lander to die in early September, at the latest. Instead, it keeps running, thus allowing it to detect on September 5th an impact created by a cluster of three asteroids, the first time scientists have ever pinpointed exactly when such a new impact occurred on Mars.

For the lander to survive for even longer, all it needs is one gust of wind across the solar panels to clean them off. The science team had expected this to happen periodically, based on past experience with the Spirit and Opportunity rovers. Unfortunately for InSight, it has not yet happened even once since it arrived on Mars in 2018. Nonetheless, it only has to happen once to save the lander.

Stay tuned. All is not yet lost.

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Jupiter’s endless interweaving storms

1:01 pm

Jupiter's endless interweaving storms

Cool image time! The photo to the right, rotated so that north is up and then reduced slightly to post here, was created by citizen scientist Thomas Thomopoulos from a raw photo taken by Juno during its 44th orbit of Jupiter.

To bring out the details Thomopoulos enhanced the colors, then enlarged the entire photo and cropped the area of interest.

Unfortunately, the Juno team that releases these photos does not provide information for easily establishing scale. In an email to me Thomopoulos noted that the largest circular storm in the northern half of the image is likely a vortex, which on Jupiter tend to range from 600 to 3,500 miles in diameter. He also noted that Juno was a little less than 27,000 miles away from Jupiter when this photo was snapped on August 17, 2022. Thus, I suspect this particular vortex sits on the larger end of that size range, which makes it a little less than half the size of the Earth.

As for the colors, as with many similar Juno images, the white clouds appear to almost always sit at the top of these storms and jets, almost like thunderheads.

Though the largest feature here is that large vortex to the north, most of the gigantic Jupiter storms visible seem instead to form as bands, the storms churning about madly as they are driven along the gas giant’s very fast ten hour rotation period.

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The strange scattered rocks of Gediz Vallis on Mars

10:28 am

The strange rocks of Gediz Vallis
Click for full image.

Cool image time! The photo to the right, reduced to post here, was taken on August 20, 2022 by Curiosity’s high resolution camera. It shows some of the scattered and very delicate rocks that it is finding on the floor of Gediz Vallis, the valley the rover had been striving for since landing more than a decade ago and finally entered in mid-August.

Because of Mars weak gravity, about 39% of Earth’s, and very thin atmosphere, about 1% of Earth’s, it is possible for surface rocks to erode into such delicate shapes. The shapes appear to be further encouraged by the many layers that exist in Mars, with each layer having different characteristics. In the case of the hanging flakes to the right, these layers were more resistant to erosion and thus remains intact while material above and below was slowly blown away.

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Some scientists make educated guess as to the number of ants on Earth

9:38 am

It’s time for junk science! By combing through thousands of research papers, a team of scientists have estimated the Earth’s population of ants numbers approximately 20 quadrillion.

So for the work, researchers combed through 12,000 reports from databases in many languages, including Bulgarian and Indonesian, finding 489 studies with rigorous enough methods of collecting and counting ants to be included. Most of the studies were not focused on ants per se but on larger questions of biodiversity and evolution and just happened to sample ants. The team was surprised to find how concentrated ants are in the tropics, being most plentiful there in savannas and moist forests.

This estimate is 2 to 20 times higher than previous guesses. It is also a somewhat pointless exercise, mostly because there is no way to check the number. It is simply an educated guess, from which little real knowledge can be gleaned.

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Webb instrument has technical issue partly preventing its use

9:31 am

Because a an issue with the mid-infrared instrument (MIRI) on the James Webb Space Telescope, the telescope’s engineering team has paused use of that instrument while it reviews the situation.

On Aug. 24, a mechanism that supports one of these modes, known as medium-resolution spectroscopy (MRS), exhibited what appears to be increased friction during setup for a science observation. This mechanism is a grating wheel that allows scientists to select between short, medium, and longer wavelengths when making observations using the MRS mode. Following preliminary health checks and investigations into the issue, an anomaly review board was convened Sept. 6 to assess the best path forward.

The Webb team has paused in scheduling observations using this particular observing mode while they continue to analyze its behavior and are currently developing strategies to resume MRS observations as soon as possible. The observatory is in good health, and MIRI’s other three observing modes – imaging, low-resolution spectroscopy, and coronagraphy – are operating normally and remain available for science observations.

I am quoting almost entirely NASA’s short announcement. The announcement is vague, confusing, and (quite typically) written to minimize the reality of the issue. I can’t figure out how MIRI’s other observing modes are available if they have paused use of a mechanism that allows them to choose modes.

Regardless, Webb is awful young to have this kind of problem.

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Interstellar clouds backlit by nearby massive star

1:27 pm

Interstellar clouds backlit by nearby massive star
Click for full image.

Cool image time! The photo to the right, cropped and reduce to post here, was taken by the Hubble Space Telescope of what astronomers believe is a newly formed massive star about 9,000 light years away that has periodically spewed out material during eruptions.

The scientists hope to use Hubble to determine the speed in which this material is flying away from the star by taking pictures at intervals and then measuring the amount of change from image to image. This data will also allow the scientists to better gauge the distance to this star, as well as its actual mass, information that will help them better understand what is happening.

I highlight this picture however simply because of its beauty. The interstellar clouds on the left are all apparently backlit by the brightest star on the right, and thus their shape is easy to perceive.

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InSight’s seismometer detects its first new impact on Mars

1:13 pm

Martian impact discovered by InSight
Click for full image.

Using data from InSight’s seismometer that suggested a new impact had occurred at a specific location on September 5, 2022 on Mars, scientists used the high resolution camera on Mars Reconnaissance Orbiter (MRO) to search and find that impact.

The photo to the right, reduced to post here, is that MRO photo.

The initial impact itself created a small marsquake that was detected by InSight’s seismometer. The instrument recorded seismological data that showed the moment the meteoroid entered Mars’ atmosphere, its explosion into pieces in the atmosphere, and finally, the impact that created a series of at least three craters in the surface.

MRO then flew over the approximate site where the impact was “felt” to look for darkened patches of ground using its Context Camera. After finding this location, HiRISE captured the scene in color. The ground is not actually blue; this enhanced-color image highlights certain hues in the scene to make details more visible to the human eye – in this case, dust and soil disturbed by the impact.

This was thus the first new Martian impact detected based on its actual occurrence, rather than simply finding a change between two photos taken at different times. The latter only tells you a time period when the impact occurred. InSight’s detection here marks the impact’s exact moment.

Nor is this the only such discovery. It appears that InSight detected at least two other impacts (here and here), that only subsequently were linked to MRO impacts. In those cases, the new impact had already been found by MRO, and only afterward were scientists able to identify its seismic vibration in InSight data, thus pinpointing the exact date it took place.

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Valeri Polykov, holder of the record’s longest stay in space, passes away

10:00 am

Valeri Polykov
Valeri Polykov

Russian astronaut Valeri Polykov, who holds the record for the longest spaceflight yet of any human in history, has passed away at the age of 80.

In 1994 and 1995 Polykov spent 437 days on Russia’s space station Mir, the equivalent of fourteen months and two weeks. His thoughts at launch, as he told me personally when I interviewed him while writing Leaving Earth, were not so confident:

“What if something goes wrong?” [he explained]. “I had sacrificed so much time. The government has spent so much, more than they can afford. And I’ve learned so much for them myself, for them.

“Better I die if something went wrong,” he thought. “Better if I had a gun to shoot myself.”

Nothing went wrong however. Polykov, a doctor, had pushed for this long mission to find out if it would be possible for a person to function after a year-plus of weightlessness upon arrival on Mars. Originally planned to last 18 months, circumstances eventually shortened it to 14 months-plus. When Polykov came home in March 1995, he managed to walk a few steps on his own, shortly after being removed from the capsule. To his mind, he had proved that a person could function on their own on Mars after such a long flight.

Others disagreed. As I wrote in Leaving Earth, though he was almost normal within a week of landing,

Polykov had come back to Earth very weak. For at least those first few hours, he needed help from those around him. Any spacefarer arriving on Mars after a year in space must be prepared to face that same challenge.

Regardless, Polykov, like Brian Binnie, was one of the early giants in space exploration. His contribution must not be forgotten.

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Webb takes its first infrared image of Mars

9:12 am

Webb's first infrared image of Mars
Click for full image.

Astronomers have now released the the James Webb Space Telescope’s first infrared image of Mars, taken on September 5, 2022.

The image to the right, cropped and reduced to post here, shows some of the data obtained. Because Mars is so close, it is actually too bright for Webb’s instruments. To get any data, the exposures were very very short, and still the brightest areas — as indicated by large areas of yellow — are overexposed. The cause of the different brightness of Hellas Basin, however, is not simply because the basin — the deepest point on Mars — is cooler.

As light emitted by the planet passes through Mars’ atmosphere, some gets absorbed by carbon dioxide (CO2) molecules. The Hellas Basin – which is the largest well-preserved impact structure on Mars, spanning more than 1,200 miles (2,000 kilometers) – appears darker than the surroundings because of this effect. “This is actually not a thermal effect at Hellas,” explained the principal investigator, Geronimo Villanueva of NASA’s Goddard Space Flight Center, who designed these Webb observations. “The Hellas Basin is a lower altitude, and thus experiences higher air pressure. That higher pressure leads to a suppression of the thermal emission at this particular wavelength range [4.1-4.4 microns] due to an effect called pressure broadening. It will be very interesting to tease apart these competing effects in these data.”

The NASA press release says the scientists are preparing a paper analyzing the spectral data and what it revealed about “dust, icy clouds, what kind of rocks are on the planet’s surface, and the composition of the atmosphere,” I suspect however that Webb’s capabilities for studying Mars are much more limited than implied, and that it will over time take much fewer images of the red planet, compared to Hubble.

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Deep inside the youngest flood lava event on Mars

1:30 pm

Deep inside the youngest flood lava event on Mars
Click for full image.

Cool image time! Today we return to the Athabasca Valles flood lava event, believed to be the youngest major lava event on Mars that I highlighted in a cool image last week.

Then, I showed two meandering lava flows near the edge of this Great Britain-sized flood lava plain, produced 600 million years ago in only a matter of weeks. Today, we take a look deep within the lava plain. The photo to the right, rotated, cropped, and reduced to post here, was taken on May 6, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label “a lava-crater interaction.”

In plain English, we are looking at a crater that has been inundated by the flood lava, filling it.
» Read more

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Starlink being tested in Antarctica

9:33 am

Capitalism in space: The National Science Foundation (NSF) has begun testing a single Starlink terminal at its McMurdo station in Antarctic, with the hope that the service can improve communications at the station significantly.

Everyone at the base shares a 17 Mbps link, according to the United States Antarctic Program, which severely limits what people can do. The station actually blocks people from using high-bandwidth apps like Netflix, cloud backups, and video calls, with the exception of once-weekly Skype or FaceTime sessions at a public kiosk or mission-critical communications.

The addition of Starlink probably doesn’t mean that McMurdo residents will be able to hold a Netflix movie night or anything — the terminals can handle around 50-200 Mbps, which still isn’t a ton to go around, even during the winter when far fewer people are at the base — but it could help make transferring important scientific data off of the icy continent easier.

According to SpaceX’s plans, this new service in Antarctica means that by year’s end Starlink will be available on all seven continents.

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New theory: Saturn’s rings came from a lost and destroyed moon

9:24 am

The uncertainty of science: According to a new computer simulation, scientists have proposed that the reason Saturn’s rings are tilted 27 degrees is because they were created by the destruction of a moon 160 million years ago, an event that was also linked to the way the orbits of Saturn and Neptune interact, combined with the on-going slow evolutionary changes in Titan’s orbit around Saturn.

Wisdom and his colleagues believe Saturn acquired its tilt because of a peculiar synchronicity: the precession of Saturn’s spin axis—the way it wobbles like a top with a particular rhythm—is suspiciously in tune with a precession in Neptune’s orbit. If Saturn and Neptune were trapped in this resonance, Saturn’s tilt would be “kind of vulnerable to other forces that could cause it to change,” says Rola Dbouk, an MIT graduate student in planetary science. In 2020, Cassini scientists discovered what the study team thinks is that external stimulus: Titan, Saturn’s largest moon, is migrating away from Saturn by 11 centimeters a year. In a study published today in Science, Dbouk, Wisdom, and colleagues show how Titan’s migration, in combination with the Saturn-Neptune resonance, could have ratcheted up Saturn’s tilt over the course of 1 billion years.

The work also yielded a potential explanation for the origin of Saturn’s rings. Using Cassini’s measurements of Saturn’s gravitational fields to model the planet’s interior structure, the researchers refined calculations for the wobble of Saturn’s spin axis and found it is no longer in sync with Neptune. “Something kicked it out of the resonance,” Dbouk says. They first ruled out the possibility that chaotic changes in the orbits of some of the largest of Saturn’s dozens of moons could be responsible. But when they added another moon to the mix, things got interesting.

In simulations, the researchers included an object about the size of Iapetus, Saturn’s third largest moon, orbiting about 43 Saturn radii out—between the orbits of Titan and Iapetus. They found this moon could have provided the necessary nudge to the resonance if it were suddenly knocked from its orbit because of chaotic interactions with its neighbors about 160 million years ago.

To say that this theory is uncertain is no different that saying the sky is blue. It is so uncertain that it is difficult to take it seriously. It could be right, but as one scientist quoted at the article noted, there is no way to test it.

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September 15, 2022 Quick space links

3:44 pm

Courtesy of BtB’s stringer Jay, who trolls Twitter so I don’t have to.

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Overlapping galaxies

9:22 am

Overlapping galaxies, as seen by Hubble
Click for full image.

Cool image time! The picture to the right, cropped and reduced to post here, was taken by astronomers using the Hubble Space Telescope, and captures two galaxies that happen to overlap in their line of sight to Earth.

The two galaxies, which have the uninspiring names SDSS J115331 and LEDA 2073461, lie more than a billion light-years from Earth. Despite appearing to collide in this image, the alignment of the two galaxies is likely just by chance — the two are not actually interacting.

This image was taken as part of the citizen-scientist project dubbed Galaxy Zoo, whereby volunteers review lower resolution images of strange-looking galaxies and propose the best for Hubble higher resolution imaging.

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Astronomers propose method for predicting the stars that will go supernovae

9:12 am

The uncertainty of science: Using a computer model based on the most recent data that suggests red supergiant stars like Betelgeuse are the kind of stars that produce certain kinds of supernovae, astronomers now think they have a method for predicting which of those stars are about to go supernovae.

You can read the science paper here. From the link above:

In a few examples, astronomers have looked back at old catalogs and found images of the stars before they exploded, and they all seem to be red supergiants like Betelgeuse. That’s a clear indication that those kinds of stars are supernova candidates, ready to go off at a moment’s notice.

The stars that result in these kinds of supernovas are thought to have dense shrouds of material surrounding them before they explode. These shrouds are orders of magnitude denser than what’s measured around Betelgeuse.

More importantly, the data suggests that once this shroud of material forms, the supernova will follow, in just a few years. As the scientists conclude in their paper:

The final overarching conclusion we can make from this work is that, shortly before core-collapse, [red supergiants] must undergo some prodigious mass-losing event which radically alters the appearance of the star. Therefore, the signature of an imminent explosion should be a dramatic change in the progenitor stars’ optical – near-IR photometry on timescales of less than a month. Such a signature should be detectable in the coming era of wide-field short cadence photometry. [emphasis mine]

Near-IR (infrared) photometry is exactly in the wavelengths in which the James Webb Space Telescope operates. Thus, if it is lucky and sees this kind of star in an image, and a supernova follows shortly thereafter, this theory will have been proven correct.

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The shattered cliffs of Mount Sharp

11:04 am

A broken cliff on Mars

Cool image time! The picture above was taken on August 11, 2022 by the left navigation camera on the Mars rover Curiosity. It shows a great example of the strange manner in which the bedrock in the layered cliffs on Mount Sharp appear to break apart.

I am not certain exactly where this feature is, or its exact scale, but based on the date and where Curiosity was located when the photo was taken, it likely is a small section from one of two hills, Deepdale and Bolivar, that Curiosity passed between in mid-August. It is likely somewhere in the panorama included in my August 11th post, but I have not yet been able to locate it.

Nonetheless, the breakage here is typical of these cliff faces. The structural strength of these layered hills is not very high, so at some point one section can break away from another as the hill sags downward to the left. What makes the cracks here more intriguing is that something caused the higher sections surrounding the main block to widen. On Earth we would assume that this widening was caused by rainwater pouring in from the top. On Mars, that explanation doesn’t hold water.

Wind? Seasonal thermal changes? Neither explains the change in the width of the cracks along their length. Maybe the wider cracks indicate an increased sagging of the hill to the left. The layers below this broken block have simply not slid to the left as much.

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InSight’s power level goes up!

5:54 pm

InSight's power levels as of September 5, 2022

The most recent status update on the Mars lander InSight, released today, shows a slight rise in the amount of power generated by its dust-covered solar panels.

As shown on the graph to the right, on August 27, 2022 the power level was 400 watt-hours generated per Martian day. On September, 5, 2022, the power level was 410 watt-hours per Martian day, the first power increase since late July. At the same time, the dust in the atmosphere continued to clear, going from a tau level of .88 to 0.8. Outside of the winter dust season tau is usually between 0.6 and 0.7.

The slight power increase continues to suggest that the lander’s death might be delayed. At 400 watt-hours per day, it has been able to run its seismometer since the beginning of July. With this slight increase, the chance increases that InSight will finally get that one gust of wind or dust devil that will blow the dust off its solar panels and allow it to recover some power and operate for longer.

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Crazy badlands in the equatorial region of Mars

2:49 pm

Badlands in the equatorial regions of Mars
Click for full image.

Cool image time! The photo to the right, rotated and cropped to post here, was taken on June 17, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The section highlighted is at full resolution, in order to make clear the absolutely crazy and complex terrain seen in the full image.

This terrain is not glacial, as the location is only about 1 degree south of the Martian equator. There might have been surface or near surface ice here once in the past, but there is none now.

Could we be looking at some form of lava flow? This is possible, because a close look at the context map at the image link suggests this region has been partly covered by some material, obscuring some craters to the east and west. However, there is no visible evidence anywhere in this region of a volcanic vent or caldera. If this covering material was volcanic it is very unclear where it came from.

The overview map below does not really provide any answers, but at least gives the context.
» Read more

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CAPSTONE in safe mode

1:07 pm

The lunar orbiter CAPSTONE, presently on its way to the Moon, went into safe mode on September 8th at the end of a mid-course correction engine burn.

The CAPSTONE mission team has good knowledge of the state and status of the spacecraft. The mission operations team is in contact with the spacecraft and working towards a solution with support from the Deep Space Network.

Under such conditions engineers almost always recover the spacecraft so that the mission proceeds as normal. No guarantees of course, but it is not unreasonable to expect the same with CAPSTONE.

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A “what the heck?!” mesa in the southern polar regions of Mars

4:49 pm

A
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on July 28, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label a “Circular and Banded Landform.”

I put this mesa into a geological category I dub “What the heck?!” We are clearly looking at a mesa, probably no more than 200 feet high, if that. What makes it baffling are the parallel bands that not only cut across the mesa but extend in the same direction for many miles in all directions. Though at first glance these bands appear to be dunes, their rocky eroded look along the mesa’s northwest rim suggests instead the bands are the top edge of many vertically oriented parallel layers, which at this mesa’s flanks are eroding alternatively at different rates.

The overview map below shows us where this mesa is located, relative to the south pole.
» Read more

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September 8, 2022 Quick space links

3:30 pm

Courtesy of string Jay:

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Russia confirms Luna-25 delayed till next year

8:42 am

The landing area for Luna-25
The landing zone for Luna-25 at Boguslawsky Crater

The head of Roscosmos, Yury Borisov, confirmed yesterday that the launch of Russia’s first lunar science probe since the 1970s has been delayed until 2023.

The Doppler speed and distance sensor made by the Vega Concern owned by the Rostech State Corporation, that could guarantee a soft landing, underperformed in terms of measurement precision, a source in the space industry told TASS in July. The launch will likely be postponed until 2023, the source added.

Russian sources had indicated in July that this delay was likely. Yesterday’s announcement merely made it certain.

This project has been under development for almost a quarter of century, which appears to be the average development time for government-run projects, whether in Russia or in the U.S. Just long enough to provide an almost entire career for bureaucrats.

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Ingenuity completes 31st flight

3:06 pm

Perseverance's location on September 2, 2022
Click for interactive map

Though no details have yet been released, the engineering team for the Mars helicopter Ingenuity has posted the numbers for the helicopter’s 31st flight, which took place yesterday.

Ingenuity flew 318 feet to a height of 33 feet for 56 seconds. The maximum ground speed was 10.6 mph. The white dot on the map to the right indicates the approximate landing spot. The blue dot Perseverance’s location as of September 3rd.

The flight plan had been to fly 319 feet, so Ingenuity landed one foot short of that plan.

That difference does not indicate any problems. However, one of the present goals of the engineering team is to improve their landing accuracy in order to provide data for the future sample return helicopter that is now in development to come and get Perseverance’s sample cores. That future helicopter will need to be able to land very precisely, and they are using Ingenuity to refine the Martian flight software.

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An example of the youngest big lava flow on Mars

1:34 pm

An example of the youngest big lava flow on Mars
Click for full image.

Overview map

Cool image time! The photo above, rotated, cropped, and reduced to post here, was taken on May 13, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows two dramatic ancient flows of flood lava. The arrows indicate what I think is the direction of flow for each, though the direction of the flow to the north appears more certain. In a wider context camera image the bulk of the evidence suggests the southern flow is heading west (as indicated by the arrow), but there are scalloped mesas within it that suggest the opposite.

The overview map above marks the location of this picture by the white cross inside the Athabasca Valles flood lava, thought by some scientists [pdf] to be Mars’ youngest major lava event that erupted about 600 million years ago and in just a matter of a few weeks poured out enough lava to cover an area about the size of Great Britain.

The general trend of the Athabasca flow was to the south, splitting into a big western and southeastern flows. This picture captures the southern edge of that southeastern flow, which might help explain why the flow directions in the picture seem so different from the main Athabasca flow. On a large scale, the flow was to the southeast. On a small scale at the edges the flow could go in many directions as the lava looks to find its level.

The Medusa Fossae Formation is the largest volcanic ash deposit on Mars, and is thought to be the source of most of the red planet’s dust. Though the origin of the ash is not yet known, it likely came from the eruptions that formed the planet’s giant volcanoes to the east and west.

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Research: Flies on ISS benefited greatly from simulated gravity

10:52 am

Scientists have found that providing fruitflies 1g of artificial gravity on ISS using a centrifuge acted to reduce the medical changes that weightlessness produces.

In this study, scientists sent flies to the space station on a month-long mission in a newly developed piece of hardware called the Multi-use Variable-gravity Platform (MVP), capable of housing flies at different gravity levels. The flies in this hardware had access to fresh food as they lived and reproduced. By using distinct compartments, the MVP allowed for different generations of flies to be separated. On the space station, one group of fruit flies experienced microgravity similar to their human counterparts. Another group was exposed to artificial gravity by simulating Earth’s gravity on the space station using a centrifuge – an instrument that spins to simulate gravity. While on the space station, cameras in the hardware recorded behavior of these “flyonauts”. At different points in time, some of the flies were frozen and returned to Earth to study their gene expression.

…More in-depth analysis on the ground immediately post-flight revealed neurological changes in flies exposed to microgravity. As the flies acclimated to being back on Earth after their journey, the flies that experienced artificial gravity in space aged differently. They faced similar but less severe challenges to the flies that were in microgravity.

You can read the paper here.

To some extent, this study tells us nothing. We already know from a half century of research that zero gravity causes negative physical changes in both fruit flies and humans. What we really need to know is the lowest level of artificial gravity that would be beneficial. It is much easier to engine a spacecraft to produce 0.1g of artificial gravity than 1g. Even 0.5g would ease the engineering problem. The problem is that we do not yet know the right number.

It is a shame the scientists didn’t subject some flies to 0.5g, just to find out if that level of artificial gravity worked to provide benefits.

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Computer model: Glaciers move slower in Mars’ gravity

10:00 am

Using a computer model that compared glacier flows on Earth and Mars, scientists have concluded that past glaciers on Mars flowed more slowly than on Earth, and produced different types of erosion features that might explain the red planet’s many riverlike geological features.

The new study modeled how Mars’ low gravity would affect the feedback between how fast an ice sheet slides and how water drains below the ice, finding under-ice channels would be likely to form and persist. Fast water drainage would increase friction at the interface of rock and ice. This means ice sheets on Mars likely moved, and eroded the ground under them, at exceedingly slow rates, even when water accumulated under the ice, the authors said.

From the paper [pdf]:

We show quantitatively that the lower surface gravity on Mars should alter the behavior of wet-based ice masses by modifying the subglacial drainage system, making efficient, channelized drainage beneath Martian ice both more likely to form and more resilient to closure. Using as an example the case of the ancient southern circumpolar ice sheet, we demonstrate that the expected finger-print of wet-based Martian ice sheets is networks of subglacial channels and eskers, consistent with the occur-rence of valley networks and inverted ridges found on the Martian highlands.

This paper confirms the sense I have gotten from the planetary community about glaciers on Mars, that it could be the flow of glaciers that formed its many meandering canyons, not liquid water. The case however is not yet proven, as this is only a computer model.

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