Tag: science

TESS in safe mode

9:43 am

NASA today revealed that on April 8, 2024 its TESS space telescope went into safe mode, for reasons that are not yet understood.

NASA’s TESS (Transiting Exoplanet Survey Satellite) entered into safe mode April 8, temporarily interrupting science observations. The team is investigating the root cause of the safe mode, which occurred during scheduled engineering activities. The satellite itself remains in good health.

The spacecraft itself remains healthy and they expect to resume science operations “in the coming days.”

That safe mode occurred while “scheduled engineering activities” were ongoing suggests that the two are linked. The lack of any details from NASA further suggests that someone did a “oops!” during those activities, and they are now scrambling to fix things.

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Idiocracy has arrived

1:54 pm

Sheila Jackson-Lee:
Sheila Jackson-Lee: “The Moon is made up
mostly of gases!””

Over the last few days the conservative press has been having a field day making justifiable fun of a number of Democrats and leftists for exhibiting incredible scientifict ignorance, an ignorance so profound as to be mind-boggling.

First, after the unusual 4.8 magnitude earthquake centered in New Jersey on April 5th, a Green Party senate candidate in New Jersey, Christina Amira Khalil, immediately tweeted, “I experienced my first earthquake in NJ. We never get earthquakes. The climate crisis is real.” The mocking on X was so great she quickly deleted the tweet.

Then, in an incredibly embarrassing segment of the television show, The View, one host, Sunny Hostin, showed off her complete lack of any scientific knowledge when she claimed that the earthquake, the solar eclipse, and even the normal arrival of the cicadas every seventeen years (which she thought happened every hundred-plus years) was evidence that climate change was real.

Finally, to top off this stream of utter empty-headiness, during an eclipse event in Texas, Congresswoman Sheila Jackson Lee gave a speech of such stunning incompetency and lack of knowledge you have to wonder how she can figure out how to put on her clothes each day. This quote has been most often used to ridicule her:
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Japan to sign deal with NASA to fly two Japanese astronauts to Moon

9:34 am

According to story in the Japanese press yesterday, a deal between Japan and NASA will be signed next week whereby Japan will have two astronauts go on Moon missions in exchange for providing cargo to the Lunar Gateway station as well as a manned lunar rover.

The report today is unclear whether those Japanese astronauts will land on the Moon, but I expect they will. The rover project is being led by Toyota. It will include a airtight cabin where spacesuits will not be necessary and passengers can also sleep, allowing for very long exploratory traverses from the landing site.

Reports of this deal have been appearing in the press since 2022, when NASA said it would involve flying one Japanese astronaut to the Moon. In December 2023 it was reported that the deal would be signed within a month. It is now April. It appears the extended negotiations have gotten Japan a second astronaut Moon walker.

NASA’s Artemis program is beginning to shape up as an international program for getting almost everyone to the Moon but Americans. I am exaggerating, but I think in the future Americans will find it easier to go on a private mission to the Moon than depend on NASA, especially because of all the international deals NASA will have to honor.

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The foot of a Martian glacier

1:00 pm

The foot of a Martian glacier
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on February 18, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as the “terminus of possible glacier-like feature.” That feature is at the lower left, at the point where glacier-like material appears to be flowing out of the channel from the northeast but then ending in an area of rough fingers.

That this looks exactly like a glacier does not guarantee that it is one, which is why the scientists insert the word “possible.” Nonetheless, the geology resembles that of a glacier, from the parallel lines along its length as well as its existence inside this channel. The location is also at 49 degrees south latitude, well within the mid-latitude strips on Mars where scientists believe many such glaciers exist.

The overview map below adds further weight to this conclusion. It also suggests that there are even more glaciers on Mars than research up to now has suggested.
» Read more

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ESA awards Thales Alenia contract to build Mars lander for Franklin rover

8:40 am

Oxia Planum drainages
The drainage patterns at the Franklin rover
landing site

Click for paper [pdf].

The European Space Agency (ESA) today awarded the Italian company Thales Alenia a €522 million contract to build the entry, descent, and landing module for ESA’s Franklin rover, now scheduled for launch in 2028.

Under this contract, Thales Alenia Space will lead the definition of the Entry, Descent and Landing Module and maintenance activities for the transfer module (carrier) and the rover, including upgrades and replacement of time-sensitive elements. A full audit and tests will be carried out on the rover to ensure its readiness for the new mission. In addition, replacement of some payload elements is planned, such as integration of the new Enfys infrared spectrometer. The batteries and tanks will be replaced on the carrier module as well as potential adjustments to align with the updated trajectories to Mars. New developments on the descent module and landing pad are also required, because the European avionics part of the descent module will be reused.

This contract was necessary because the project was initially a partnership with Russia, whereby Russia provided this lander as well as the launch services. That partnership was severed after Russia invaded the Ukraine, which caused this mission to Mars to be delayed four to six years.

NASA then chipped in $30 million to help pay for launch out of Cape Canaveral, though no launch company has been announced. I suspect both ESA and NASA wish to wait before making a deal, considering how launch costs are dropping. At present it is impossible to predict the landscape of that market in 2028.

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A whirlpool half-hidden by dust

10:23 am

A whirlpool half-hidden by dust
Click for original image.

Cool image time! The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope and shows us a magnificent spiral galaxy about 100 million light years away that also has very active nucleus at its center as well as many star-forming regions (in blue) in its outer arms.

That we do not see the same blue spiral arms on the right side of the photo is not because they are lacking, but because a very large stream of dust blocks our view.

This dark nebula is part of the Chamaeleon star-forming region, itself located only around 500 light-years from us, in a nearby part of the Milky Way galaxy. The dark clouds in the Chamaeleon region occupy a large area of the southern sky, covering their namesake constellation but also encroaching on nearby constellations, like Apus. The cloud is well-studied for its treasury of young stars, particularly the cloud Cha I, which has been imaged by Hubble and also by the … James Webb Space Telescope.

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Lunar Reconnaissance Orbiter snaps a smeared image of South Korea’s Danuri lunar obiter

10:04 am

Danuri as seen by LRO
Click for original image.

Cool image time! On March 5 to March 6, 2024, the orbits of NASA’s Lunar Reconnaissance Orbiter (LRO) and South Korea’s Danuri orbiter had three close approaches, during which LRO had a chance to snap pictures of Danuri as it zipped by in the opposite direction.

The first image is to the right, cropped but expanded to post here.

The flight paths of the two vehicles were nearly parallel but in opposite directions, resulting in extreme relative velocity. The LROC NAC exposure time was very short, only 0.338 milliseconds. But still, Danuri was smeared by a factor greater than 10x in the downtrack direction.

…On the first opportunity, LRO was slewed 43 degrees to capture Danuri from a distance of 5.0 kilometers

Of the three pictures taken, this one appears the best. In all three cases, the fast relative speed was too fast for the camera shutter, so that Danuri’s image was smeared as you see.

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Today’s eclipse

9:49 am

The next eclipses to cross the U.S.
Map by Michael Zeiler (GreatAmericanEclipse.com). Click for original.

Today a solar eclipse will cross some of the most populated areas of Mexixo, the United States, and Canada, as shown on the map to the right.

We shall not see such an event in North America again until 2046, and that will only cover a small part of the Pacific northwest. If you have never seen such an event, get your eclipse glasses (essential if you don’t want to go blind), take some time off of work, and go see it today. This link from Sky & Telescope covers about everything you need to know.

The experience is very hard to describe, though I tried when Diane and I traveled to South Bend, Idaho, in 2017 to experience that eclipse. As I wrote,

Totality was amazing. I was amazed by two things. First, how quiet it became. There were about hundred people scattered about the hotel lawn, with dogs and kids playing around. The hotel manager’s husband set up speakers for music and to make announcements, but when totality arrived he played nothing. People stopped talking. A hush fell over everything. Moreover, I think we somehow imagine a subconscious roar from the full sun. Covered as it was, with its soft corona gleaming gently around it, it suddenly seemed still.

Secondly, the amazing unlikeliness of the Moon being at just the right distance and size to periodically cause this event seemed almost miraculous. Watching it happen drove this point home to me. And since eclipses themselves have been a critical event in the intellectual development of humanity, helping to drive learning and our understanding of the universe, it truly makes me wonder at the majesty of it. I do not believe in any particular religion or their rituals (though I consider the Bible, the Old Testament especially, to be a very good manual for creating a good life and society), but I do not deny the existence of a higher power. Something made this place, and set it up in this wonderous way. Today’s eclipse only served to demonstrate this fact to me again.

I am sure your impressions will be unique to you.

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Varda quickly raises $90 million after completing its first orbital manufacturing mission

2:18 pm

As expect, Varda announced yesterday that it raised $90 million in investment capital following the publication of the results of its first orbital manufacturing mission, where its returnable capsule was used to produce test pharmaceuticals in space that cannot be made on Earth.

Varda announced April 5 it raised a Series B round led by venture firm Caffeinated Capital, with participation from Lux Capital, General Catalyst, Founders Fund and Khosla Ventures. The company has raised $145 million to date. The funding round comes on the heels of the successful conclusion of its first demonstration mission, W-1, on Feb. 21 when the company’s capsule landed at the Utah Test and Training Range. The capsule had been part of a spacecraft launched in June 2023 to test the ability to produce pharmaceuticals in microgravity.

The new funding will allow Varda to scale up production of spacecraft that take advantage of microgravity to produce pharmaceuticals that are not possible or cost-effective to make on the ground.

The company already has a second returnable capsule scheduled for launch this summer on a Rocket Lab Electron rocket.

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The taffy terrain in Mars’ death valley

1:42 pm

Taffy terrain in Hellas Basin on Mars

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on February 21, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled “banded terrain and layering,” it actually is a good example of “taffy terrain,” a weird Martian geological formation unique to the Red Planet that scientists as yet don’t quite understand. This 2014 paper only says this:

The apparent sensitivity to local topography and preference for concentrating in localized depressions is compatible with deformation as a viscous fluid. In addition, the bands display clear signs of degradation and slumping at their margins along with a suite of other features that include fractured mounds, polygonal cracks at variable size-scales, and knobby/hummocky textures. Together, these features suggest an ice-rich composition for at least the upper layers of the terrain, which is currently being heavily modified through loss of ice and intense weathering, possibly by wind.

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Voyager-1 still out of commission

8:05 am

Though engineers have now confirmed the cause of the computer problem that has prevented Voyager-1 from sending back readable data, a fix has not yet been attempted and the spacecraft remains in safe mode.

In early March, the team issued a “poke” command to prompt the spacecraft to send back a readout of the FDS [Flight Data Subsystem] memory, which includes the computer’s software code as well as variables (values used in the code that can change based on commands or the spacecraft’s status). Using the readout, the team has confirmed that about 3% of the FDS memory has been corrupted, preventing the computer from carrying out normal operations.

The team suspects that a single chip responsible for storing part of the affected portion of the FDS memory isn’t working. Engineers can’t determine with certainty what caused the issue. Two possibilities are that the chip could have been hit by an energetic particle from space or that it simply may have worn out after 46 years.

Although it may take weeks or months, engineers are optimistic they can find a way for the FDS to operate normally without the unusable memory hardware, which would enable Voyager 1 to begin returning science and engineering data again.

Considering that Voyager-1’s power supply will run out sometime in 2026, after almost a half century of operation, the engineers really don’t have that much time to fix the problem and resume science operations.

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Engineers confirm IXPE is fixed and resuming science observations

10:00 am

Engineers have now confirmed the software fix they sent to the IXPE space telescope on March 26, 2024 has worked, and have taken the telescope out of safe mode so that it can resume science observations.

The IXPE mission is now observing a new transient X-ray source – Swift J1727.8–161 – a candidate accreting black hole. The source has recently begun producing jets of material moving at a fraction of the speed of light. The IXPE observations will help to understand accretion onto black holes, including potentially revealing how the relativistic jets are formed.

The telescope observes the universe in X-rays, but does so by observing its polarization. This approach provides information not seen in direct observations.

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Complex ridged terrain in ancient Martian crater

2:06 pm

Complex ridges in an ancient Martian crater
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken on January 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Because an electronic unit for one of this camera’s filters has failed, causing a blank strip in the image center, I have filled in that gap using an MRO context camera image taken October 31, 2015.

The scientists describe this geology as “ridged terrain.” What I see is a surface that was like wet plaster once, and then a giant finger touched it and pulled away quickly, so that as it left some material pulled upward to create random ridges within the depression created by that finger.

These ridges are inside a very very ancient 110-mile-wide crater dubbed Margulis. According to the 2021 poster [pdf] of the scientists who did the first geological mapping of this crater, the crater floor “show remnants of sedimentary materials, suggesting the [crater was] subjected to widespread episodes of resurfacing and denudation.”

Though located in the dry equatorial regions, this ridged terrain suggests it formed suddenly when underground ice sublimated into gas, bursting upward to break the surface when the gas pressure became high enough.
» Read more

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Patches of volcanic Martian ash covering patches of frozen volcanic dunes

11:30 am

Patches of volcanic Martian ash over frozen volcanic dunes

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on December 24, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

What makes this terrain intriguing are the series of parallel ridges that cover most of the picture, with smaller ridges at right angles filling the hollows between. It appears we are looking at two different sets of dunes, the larger ridges indicating the southeast-to-northwest direction of the prevailing winds, while the smaller ridges in the hollows suggest the wind patterns within the hollows, causing smaller ripple dunes to form at right angles.

Note however the flat patches in the lower left. The material there appears to fill the hollows, covering the dunes. We can tell this by the hollows to the east, which have an almost identical dune pattern. Those flat patches then are likely covering similar dunes, with the patched material either having been blown away to expose the lower dunes, or having been blown here to cover them in patches. That the dunes appear unchanged under this patched material when exposed also suggests strongly that these dunes are hardened into stone, no longer soft sand that can be blown by the wind.
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Sunspot update: The weak solar maximum continues

10:38 am

NOAA yesterday posted its updated monthly graph tracking the number of sunspots on the Sun’s Earth-facing hemisphere. As I do every month, I have posted this graph below, with several additional details to provide some larger context.

The sunspot activity in March dropped, continuing the pattern of the last five months, where the Sun appears to be in a stable plateau after reaching a high peak in the summer of 2023. It continues to appear that we are in the middle low saddle of a double-peaked relatively weak solar maximum, with the Sun doing what I predicted in February:

If we are now in maximum, sunspot activity throughout the rest of 2024 should fluctuate at the level it is right now, with it suddenly rising again near the end of the year for a period lasting through the first half of 2025. After that it should begin its ramp down to solar minimum.

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Interacting galaxies

9:27 am

Interacting galaxies
Click for original image.

Cool image time! The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope as part of a dark energy survey. It shows two galaxies very close together, their perpheries only about 40,000 light years apart, with the larger galaxy about the size of the Milky Way.

For comparison, the Large Magellanic Cloud (LMC) is about 167,000 light years from the Milky Way, more than four times farther that this satellite galaxy. Yet the satellite galaxy here appears much larger than the LMC, having a central core that the LMC lacks. From the caption:

Given this, coupled with the fact that NGC 5996 is roughly comparable in size to the Milky Way, it is not surprising that NGC 5996 and NGC 5994 — apparently separated by only 40 thousand light-years or so — are interacting with one another. In fact, the interaction might be what has caused the spiral shape of NGC 5996 to distort and apparently be drawn in the direction of NGC 5994. It also prompted the formation of the very long and faint tail of stars and gas curving away from NGC 5996, up to the top right of the image. This ‘tidal tail’ is a common phenomenon that appears when galaxies get in close together, as can be seen in several Hubble images.

In this single picture we are witnessing evidence of a process that has been going on for likely many millions of years.

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Varda releases results of its in-orbit test for producing pharmaceuticals in weightlessness

9:48 pm

On March 20, 2024 Varda released the results from its seven-month-long flight of its unmanned capsule, claiming that the technology worked to produce pharmaceuticals in weightlessness that will be better at treating some difficult illnesses such as HIV.

From the abstract of the preprint paper [pdf]:

Despite notable progress in realizing the benefits of microgravity, the physical stability of therapeutics processed in space has not been sufficiently investigated. Environmental factors including vibration, acceleration, radiation, and temperature, if not addressed could impact the feasibility of in-space drug processing. The presented work demonstrates the successful recovery of the metastable Form III of ritonavir generated in orbit. The test samples and passive controls containing each of the anhydrous forms of ritonavir; Form I, Form II, Form III, and amorphous exhibit excellent stability. By providing a detailed experimental dataset centered on survivability, we pave the way for the future of in-space processing of medicines that enable the development of novel drug products on Earth and benefit long-duration human exploration initiatives.

More research is likely required, but I suspect Varda will be able to raise investment capital from this success, since there is a lot of money to be made from pharmaceuticals that can only be produced in weightlessness.

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The Martian view from high on Mount Sharp

11:47 am

The Martian view of mountains
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was downloaded today from left navigation camera on the Mars rover Curiosity.

The image looks to the north from the lower foothills of Mount Sharp. The view is downhill across the floor of Gale Crater. The intermittent dotted red line that weaves between those foothills marks the approximate route that Curiosity took to climb through them to reach this point.

About 20 to 25 miles away the mountainous rim of the crater can be seen dimly. The air is filled with dust, because its is almost the peak of the dust season at Gale Crater, located just south of the Martian equator.

The overview map below provides some further context.
» Read more

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China working to save classifed lunar mission from launch failure

9:40 am

Orbital data now suggests that Chinese engineers are attempting to save a classifed lunar mission from the failure of its launch rocket to put the two satellites in their proper high orbit.

The small DRO-A and B spacecraft launched from Xichang spaceport on a Long March 2C rocket March 13. Hours later, the first acknowledgement of the mission came from Chinese state media Xinhua, which announced that the spacecraft had not been inserted accurately into their designated orbit by the rocket’s Yuanzheng-1S upper stage. “The upper stage encountered an abnormality during flight, causing the satellites to fail to accurately enter the preset orbit,” Xinhua stated. “Relevant disposal work is currently underway,” it added, citing Xichang launch center.

Data from the U.S. Space Force’s 18th Space Defense Squadron (SDS) initially showed objects associated with the launch in low Earth orbit (LEO). However, subsequent Two Line Element (TLE) data sets, a mathematical representation of a satellite’s mean orbit, from 18 SDS show an object from the launch (international designator 2024-048A) in a 525 x 132,577-kilometer, highly-elliptical, high Earth orbit. This has since been raised, with the spacecraft tracked in a 971 x 225,193-km orbit on March 26.

This indicates that at least one satellite, and perhaps both—if still attached to one another—separated from the upper stage, and that the object’s orbit has been raised.

It is very possible that further engine burns could put these satellites into lunar orbit, which would then save the mission and turn the March 13 launch failure into a success.

Why China is keeping this particular lunar mission so secret is another question, that still remains unanswered.

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Martian waves of ridges and cracks

12:42 pm

Martian waves of ridges and cracks
Click for original image.

In preparing today’s cool image I initially planned to post an picture taken on December 26, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), as it showed a strange series of ridges that almost resembled waves or ripples on a pond.

In digging into MRO’s context camera archive to get the larger context, however, I immediately switched to the photo on the right, cropped, reduced, and sharpened to post here. Taken on December 17, 2010, it shows a much more mysterious and striking set of geological features than the closer view of the high resolution image, with the wave-shaped ridges on its western half but another set of wave-shaped cracks on its eastern half.

Even more intriguing, the arcs for the ridges curve in the opposite direction from the arcs for the cracks. It is almost as if there were two flows moving in opposite directions, right next to each other.
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The remnant of the supernova from 1181, as seen in multiple wavelengths

9:44 am

Supernova remnant as seen in multiple wavelengths
Click for original image.

Using a number of different telescopes and observing in many wavelengths outside the visible spectrum, astronomers have produced a new composite image of the remnant of a supernova that was detected in the year 1181 and remained visible to the naked eye for about six months.

That composite picture is to the right, cropped and reduced to post here. From the press release:

X-ray observations by ESA’s XMM-Newton (blue) show the full extent of the nebula and NASA’s Chandra X-ray Observatory (cyan) pinpoints its central source. The nebula is barely visible in optical light but shines bright in infrared light, collected by NASA’s Wide-field Infrared Space Explorer (red and pink). Interestingly, the radial structure in the image consists of heated sulfur that glows in visible light, observed with the ground-based Hiltner 2.4 m telescope at the MDM Observatory (green) in Arizona, USA, as do the stars in the background by Pan-STARRS (white) in Hawaii, USA.

Because the remnant is so dim in visible light, it has taken years of searching to locate it.

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SLIM survives its second lunar night, re-establishes contact

9:33 am

SLIM's view after surviving its 2nd night on the Moon
Click for original image.

According to Japan’s space agency JAXA, the SLIM lunar lander has successfully survived its long night on the Moon, re-establishiing contact with ground controllers yesterday.

Last night, we received a response from #SLIM, confirming that the spacecraft made it through the lunar night for the second time! Since the sun was still high and the equipment was still hot, we only took some shots of the usual scenery with the navigation camera

One of those pictures is to the right, reduced slightly to post here. It looks west across the floor of Shioli Crater, with the far rim about a thousand feet away. The picture is identical to previous images, tilted because the spacecraft landed on its side and has limited scientific capabilities, being primarily an engineering test mission.

That this engineering test has now survived two lunar nights speaks well for its design. It tells us that future Japanese lunar landers (and rovers) will have a good chance of surviving for a long time on the Moon.

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Scientists release detailed geological map of the landing site for Europe’s Franklin rover

10:01 am

Low resolution cropped section of map
Click for original image.

Scientists today released a new high resolution and very detailed geological map of the landing site for Europe’s Franklin rover, produced using orbital data from the U.S.’S Mars Reconnaissance Orbiter and Europe’s Trace Gas Orbiter.

A very low resolution version of the map is to the right.

The work was divided into 134 one-square-kilometre areas, so that the [80-person] team could fully cover the estimated landing area. Scientists used a web-based system that allowed everyone to work on the map in parallel. The software was provided by NASA’s Jet Propulsion Laboratory and set up at ESA [European Space Agency]. Data came from the Colour and Stereo Surface Imaging System (CaSSIS) onboard the ExoMars Trace Gas Orbiter and several instruments on NASA’s Mars Reconnaissance Orbiter (MRO), including the HiRISE camera, which returns images from Mars orbit at 25 cm per pixel.

The mapping leads then pieced together the information on all the areas to form a coherent map that shows the geology of the landing site in unprecedented detail. The map includes the main types of bedrock, and structures with distinct shapes like ridges and craters. It even features the material that rests on top, for example blown by the wind, or thrown long distances when meteorites impacted the surface.

The result is the highest resolution map of Oxia Planum yet, created at a scale of 1:25 000, by which every centimetre equals 250 metres on the martian surface. An average drive of 25 to 50 metres a day for Rosalind Franklin would be one to two milimetres on the map.

The team had the extra time to compile this map because the launch of Franklin to Mars was delayed a number of times because of engineering issues and the Ukraine War, which ended the Europe’s partnership with Russia, requiring ESA to find other means to launch and land the rover.

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Data from Perseverance suggests the delta in Jezero Crater was formed by a wide variety of different “fluvial” events

9:43 am

Jezero Crater delta
Jezero Crater delta

Using data from the Perseverance rover in Jezero crater, scientists now conclude that the delta that poured through a gap in the crater’s rim was formed by a wide variety of different “fluvial” events, not a steady flow as previously assumed.

From the paper’s conclusions:

The origin of this variability as well as that of the high discharge represented by the boulder conglomerate is still unknown. Realistic hypotheses include seasonal variations due to melting of snow, glacial input with possible episodic surges punctuating more regular fluvial input, or arid climate type of flows with intense storms and related flash floods.

We do not speculate further about the nature of fluvial activity in this study. However, the variability and the presence of high discharge rates have important implications on the lake evolution. Firstly, previous modeling of Jezero delta formation used steady-state discharge rates to estimate the time required to form the delta, an assumption that we can no longer justify according to our observations. Secondly, estimates of discharge rates … may be used as upper limits for some of the peak discharge rates, although the number of flood events is still difficult to determine from the sparse outcrops and the ubiquitous presence of scree.

In other words, the delta was not formed by a single event or a long stream of liquid flowing into the crater to form the lake that scientists believe once filled the crater. Instead, that flow varied, involved numerous distinct and different events over time, and likely included glacial ice transport as well.

Not that this is a surprise, but as always, the closer we get to a planet and the more detailed our data about it, the more complicated we find its nature and origins.

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The spiraling magnetic field surrounding the Milky Way’s central supermassive black hole

9:19 am

The magnetic field lines surrounding Sagittarius A*
Click for original image.

Astronomers have now produced the first detailed image of polarized light surrounding the Milky Way’s central supermassive black hole, dubbed Sagittarius A* (pronounced “Sagittarius A-star”) which in turn maps out the spiraling field lines of that black hole’s magnetic field.

The image to the right, reduced to post here, shows that image. From the press release:

“What we’re seeing now is that there are strong, twisted, and organized magnetic fields near the black hole at the center of the Milky Way galaxy,” said Sara Issaoun, CfA NASA Hubble Fellowship Program Einstein Fellow, Smithsonian Astrophysical Observatory (SAO) astrophysicist, and co-lead of the project. “Along with Sgr A* having a strikingly similar polarization structure to that seen in the much larger and more powerful M87* black hole, we’ve learned that strong and ordered magnetic fields are critical to how black holes interact with the gas and matter around them.”

Light is an oscillating, or moving, electromagnetic wave that allows us to see objects. Sometimes, light oscillates in a preferred orientation, and we call it “polarized.” Although polarized light surrounds us, to human eyes it is indistinguishable from “normal” light. In the plasma around these black holes, particles whirling around magnetic field lines impart a polarization pattern perpendicular to the field. This allows astronomers to see in increasingly vivid detail what’s happening in black hole regions and map their magnetic field lines.

Despite this similarlity, it still remains a mystery why the much larger M87 black hole is very active while Sagittarius A’ remains generally quiet.

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Engineers resolve issue on IXPE space telescope

9:01 am

Engineers have resolved the issue on the IXPE (Imaging X-ray Polarimetry Explorer) space telescope that was jumbling the data it was sending to Earth, and expect to return it to full science operations shortly.

On March 26, using procedures developed following that previous interruption, the team initiated a spacecraft avionics reset to address the issue, which put IXPE into a planned safe mode. The team has confirmed that IXPE is once again transmitting valid telemetry data and is now working to resume science operations, in as rapid and safe a manner as possible. The spacecraft is in good health.

The “previous interruption” was in 2023. In both cases it appears that simply rebooting the telescope’s software fixed the problem.

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Bursting bubbles of water gas on Mars

12:41 pm

Bursting bubbles on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on January 12, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Because of a technical issue that leaves a blank strip down the center of recent high-res MRO images, I have filled in that gap using a MRO context camera photo taken on January 12, 2015. The resolution is much less, but by doing so we can see the ground features as a unit.

What are we looking at? According to the scientists, this picture shows “fresh-looking ruptures,” referring to the broken line of sharp tears inside that meandering canyon that almost resemble a fresh wound in flesh. As this location is at 28 degrees south latitude, it lies on the edge of dry equatorial regions, where orbital images have sometimes found hints of a few remaining buried glaciers that are much more common closer to the poles.

In this case it appears the warmer equatorial climate has acted to heat up the buried ice so that it sublimated into gas. At some point the gas pressure caused the surface to burst, much like bubbles bursting on the surface of a pot of simmering tomato sauce, leaving behind these scars.
» Read more

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Intuitive Machines: Odysseus is dead

8:53 am

In a tweet on March 23, 2024 the company Intuitive Machines announced that the mission of its first lunar lander, Odysseus, is officially over with the spacecraft failing to come back to life after sunrise on the Moon.

As of March 23rd at 1030 A.M. Central Standard Time, flight controllers decided their projections were correct, and Odie’s power system would not complete another call home.

The engineers had begun listening for a signal on March 20th, when their computer models said enough sunlight would reach the solar panels to charge its communications system.

The failure of the lander to survive the lunar night is a disappointment, but it was never considered a strong possibility. Right now the company’s main task is to prevent the issues that caused Odysseus to land too fast and tip over, so that the next two missions, scheduled for either this year or next, each deliver their payloads properly on the Moon’s surface.

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The tangled view of astronomers

11:06 am

A protostar in formation
Click for original image.

The uncertainty of science: The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope as part of a survey of young stars surrounded by an edge-on dust disk. From the caption:

FS Tau is a multi-star system made up of FS Tau A, the bright star-like object near the middle of the image, and FS Tau B (Haro 6-5B), the bright object to the far right that is partially obscured by a dark, vertical lane of dust. The young objects are surrounded by softly illuminated gas and dust of this stellar nursery. The system is only about 2.8 million years old, very young for a star system. Our Sun, by contrast, is about 4.6 billion years old.

The blue lines on either side of that vertical dust lane are jets moving out from FS Tau B. The caption says their asymetrical lengths are likely due to ” mass is being expelled from the object at different rates,” but it just as easily be caused by the angle in which we see this object, making the nearer jet seem longer than the one behind.

That astronomers cannot move around such an object and see it from many angles explains the headline of this post. We can only see astronomical objects from one angle, and when they are complex objects such as this one, a large part of the research problem is disentangling the shapes we see into a coherent picture. Spectroscopy helps a lot, as it provides information about the speed and direction of different parts of the object, but even this can be enormously complicated and difficult to interpret.

Remember these facts when you read news reports about astronomical research. No matter how certain the press release sounds, its certainty is always tempered by many unknowns, some very pedestrian but fundamental.

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