Tag: exploration

Curiosity looks closely at the broken slab that had been stuck on its drill bit

12:37 pm

The rock Atacama
Click for original image.

As expected, the science team for the Mars rover hasdecided before moving on it would take a close look at the 28 pound slab of rock that had been stuck on its drill bit and when finally dropped free broken into several pieces when it hit the ground.

The top picture to the right, cropped and reduced to post here, shows that entire rock, labeled Atacama by the science team. The two insets below are close-ups of the delicate layering at the rock’s left edge as well as the drill hole itself. From team’s update today:

The highest-priority activities after liberating the drill included imaging the drill with Mastcam and ChemCam RMI, and imaging into the now-empty drill hole with MAHLI (the image above). The science team made the most of the freshly-broken surfaces created when Atacama fell back to Mars, and the freshly-exposed sand once hidden underneath Atacama.

The exposed sand is off camera, to the right. Expect a paper published about that sand, buried likely for millions of years, sometime in the next year or so.

The delicate flutes at the rock’s left edge are somewhat common rock features seen by Curiosity, made possible by Mars’ thin atmosphere and its one-third Earth gravity. On Earth the gravity and weather generally destroys such things. On Mars the lack of violent weather and light gravity allows them to form, and the thin wind even helps in their formation.

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Springtime on the residual icecap of the Martian south pole

11:42 am

Weird hatchwork at the Martian south pole
Click for original image.

Cool image time! The picture to the right, cropped and rotated so that north is to the top, was taken on March 28, 2026 by the high resolution camera of Mars Reconnaissance Orbiter (MRO).

It shows what the science team labels a “south polar residual cap site.” The location is about 200 miles from the Martian south pole, well within the south polar ice cap. A second picture of this same spot was taken only a few days later, and was labeled “bright and dark fans on patterned ground.” With the second image the science team added their nickname for this location, “Troy,” which makes referencing it easier.

The hatchwork is the mystery here. In fact, the scientists have been monitoring this geology since 2020 to see if there have been any changes, either long term or seasonally. Almost certainly they have spotted seasonal changes, as indicated by the hatchwork itself and explained below, but I don’t access to the higher resolution images that would show any major modifications on a larger scale.
» Read more

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Testing new high speed rotors for the next generation of Mars helicopters

8:28 am

Ingenuity with missing blade
Ingenuity with its missing blade, at its final resting place on Mars.
Click for original image.

Engineers from JPL and the aerospace company AeroVironment have been testing a new set of high speed rotors that they hope to use on the next generation Mars helicopters, designed to increase their payload capacity by as much as 30%.

The rotors of Ingenuity — the first helicopter to fly on Mars — never spun faster than 2,700 rpm, because at faster speeds it would be approaching the speed of sound (on Mars), when unpredictable things could happen. Engineers are pushing those limits with these new rotors, in a chamber mimicking the thin Martian atmosphere.

The test engineers had taken the precaution of lining part of the chamber with sheet metal in case the blades broke apart during the supersonic experiment. From a control room a few yards away from the chamber, the team watched displays showing data and a view inside the chamber as the rpm climbed as high as 3,750. At that rate, the tips were traveling at Mach 0.98 [just under the Martian speed of sound]. Then the engineers activated a fan inside the chamber that pelted the rotors with headwinds. After each run, they increased in wind velocity for the next run.

The team pushed rotor tip speeds to Mach 1.08, boosting the Mars vehicle’s lift capability by 30%. This breakthrough allows future missions to support heavier scientific payloads, including advanced sensors and larger batteries for extended flight. Next the team tried their luck with the two-bladed SkyFall rotor. Because it is slightly longer than the three-bladed version, only 3,570 rpm was needed to achieve the same near-supersonic speed at the rotor tips prior to introducing the headwinds.

NASA administrator Jared Isaacman has said he wants to send a fleet of helicopters to Mars in 2028, on that first nuclear-powered mission. Whether or not that mission happens as he proposed, there is ample evidence scientists plan on sending more helicopters there in the next few years (see here, here, here). These tests lay the groundwork for those future missions.

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Juno flies past the Jupiter moon Thebe

11:07 am

Jupiter's moon Thebes
Click for original image.

Though the Jupiter orbiter Juno is in its final orbits as it is running out of fuel, on May 1, 2026 it did a close fly-by of the 50 by 72 mile-wide Jupiter moon Thebe, getting within 3,100 miles.

The picture to the right, cropped and expanded to post here, is the best image released from that fly-by. It is very comparable to a photo taken by the Galileo orbiter on January 4, 2000. Both show the very large crater, dubbed Zethus.

The picture was taken by Juno’s Stellar Reference Unit (SRU) camera, designed not to do science but to “image star fields for navigation.” Thus, the picture is somewhat fuzzy, and was pointed poorly so the moon is on the far right, almost off camera.

It is very unclear how much longer Juno will function. It has apparently survived attempts by the Trump administration to zero out its operating budget, but there have been indications that its fuel supply is low.

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Curiosity unintentionally picks up a rock slab

11:15 am

Sequence showing slab picked up and then dropped
Click for movie. Original images found here, here, here, and here.

In their latest drilling campaign using the drill on the Mars rover Curiosity, the science team picked up a big surprise that could have been a serious problem, but turned out all right in the end. When they tried to extract the drill from the hole, the drill instead stayed stuck to the rock, and picked the whole rock up instead.

The four images to the right show the sequence, sourced from here, here, here, and here.

On April 25, 2026, Curiosity drilled a sample from a rock nicknamed “Atacama,” which is an estimated 1.5 feet in diameter at its base, 6 inches thick and weighs roughly 28.6 pounds (13 kilograms). When the rover retracted its arm, the entire rock lifted out of the ground, suspended by the fixed sleeve that surrounds the rotating drill bit. Drilling has fractured or separated the upper layers of rocks in the past, but a rock has never remained attached to the drill sleeve. The team initially tried vibrating the drill to shake off the rock, but saw no change.

Then, on April 29, they tried reorienting Curiosity’s robotic arm and vibrating the drill again. Imagery in the GIF shows sand falling from Atacama, but the rock stayed attached to the rover.

Finally, on May 1, Curiosity’s team tried again, tilting the drill more, rotating and vibrating the drill, and spinning the drill bit. The team planned to perform these actions multiple times but the rock came off on the first round, fracturing as it hit the ground.

Had they not been able to release the rock it could have seriously impacted the mission, even ended it.

As noted by the science team in their own update today about this situation:

Future activities involve wrapping up the drill campaign on Atacama and, nominally, seeking a more firmly rooted drill target in order to collect drill tailings for analysis, which were lost from Atacama as part of the effort to dislodge the drill bit from the rock.

In other words, they are going to have hunt around for a better drill spot, as they really do want to study some drill samples at this location. They have left the boxwork area and have moved uphill closer to the pure sulfite unit, and want to see how the geology has changed.

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A cool crater in Starship’s prime candidate zone on Mars

11:14 am

Overview map

Crater in the Starship landing zone on Mars
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken on August 16, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). In mid-March it was featured as a captioned image by MRO’s science team. From their caption:

When they form, impact craters dig up material from below the surface and throw it outwards into what geologists call an ejecta blanket. The fastest ejected material travels the furthest so material from different depths can end up at different distances from the crater.

This HiRISE image shows a pedestal crater in Arcadia Planitia that has material of different brightness and color at various distances from the crater. This could tell us more about the material that’s buried below the surface here, but the situation is complex.

The caption however fails to mention the most interesting two aspects of this crater’s ejecta blanket. One, it suggests strongly that there was a lot of near surface ice at impact that melted to produce this splash apron.

Second, and even more intriguing, the 3,100-foot-wide unnamed crater is located smack dab in the middle of the candidate landing zone on Mars for SpaceX’s Starship spacecraft, as shown by the overview map above. The white dot marks the location of this crater, while the red dots mark the four prime landing sites, as suggested by scientists in a 2021 paper [pdf], based on conclusions drawn from two workshops organized by SpaceX and these scientists. The other dots are other MRO images of this region, and include a number of potential secondary landing sites.

This zone is in the northern lowland plains of Mars, in a mid-latitude region where near-surface ice is plentiful. The splash apron of this crater provides further evidence of that near surface ice.

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Curiosity looks at a small crater as it climbs Mount Sharp

11:50 am

Antofagasta crater
Click for full resolution. Click here, here, and here for original images.

Cool image time! The panorama above, created from three pictures taken by the right navigation camera on the Mars rover Curiosity (see here, here, and here), takes a look at a small relatively fresh crater on the slopes of Mount Sharp. From an update from the rover’s science team yesterday:

At the beginning of the week, Curiosity arrived right on target on the rim of the 10-meter (33 feet) “Antofagasta” crater. The crater looked fresh and deep as we had hoped with a nice well-defined rim that didn’t look too eroded, but the bottom of it turned out to be filled with dark rippled sandy material that covered up the most interesting rock layers. There were a few rock exposures just above the sand cover that seemed like they might have been deep enough to have been sheltered from space radiation between the time their sediments were deposited and the crater-forming impact, but reaching them from the rim would have put the rover at such an awkward angle that we wouldn’t have been able to deliver the sample to the instruments.

Overview map
Click for interactive map.

It’s possible that we might have been able to get into a better position by instead placing the rover on the rippled crater fill, but the chance that the rover could get stuck in all that sand made it much too high a risk. We also looked at the nearby blocks in case they could have been ejecta from the crater, but since all the rocks visible in the crater wall looked very similar to each other, there wasn’t a good way to tell which ejecta blocks might have come from the deeper layers of the crater. Because of this, the team decided against attempting to drill in or around the crater.

The overview map to the right provides the context. The blue dot marks Curiosity’s location when the pictures above were taken. The yellow lines roughly indicate the area covered by the panorama. The red dotted line marks the future planned route, the white dotted line the rover’s actual travels.

Note the flat rocks in the foreground of the panorama, all part of the crater’s rim. Each looks like a large flat paving stone that was very precisely shattered into numerous tiny pieces, all about the same size. Very strange. On Earth you’d assume some craftsman had laid these small pieces down like tiles, but of course, that couldn’t have happened on Mars.

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NASA’s IG: With only Axiom building NASA’s future spacesuits, the agency’s lunar program faces great scheduling risk

12:23 pm

Axiom's two spacesuits being tested underwater
Axiom’s two spacesuits being tested underwater in October 2025.
Click for original.

According to NASA’s inspector general’s report today [pdf] on the state of NASA’s effort to create new spacesuits for use by its astronauts on future space stations as well as in its Artemis lunar program, the planned schedules for the lunar landing and those stations are threatened because the agency presently has only one contractor, Axiom, building new suits, and has not established any spacesuit standardization rules should it want to issue contracts to others. From the report’s conclusion:

While NASA is taking steps to mitigate schedule risk, it must also contend with the unique risks inherent to a single-provider environment until future competition is introduced. … If Axiom cannot satisfy its contractual requirements in a timely or cost-effective manner, then NASA could be forced to continue using the problematic EMUs throughout the life of the ISS and significantly adjust its lunar plans. [EMUs are the complex suits presently used on ISS, and would not work well for any lunar landing mission.]

While xEVAS [the new suit concept] is flexible enough to allow for additional providers, doing so may not help the Agency meet its more immediate Artemis goals. Critically, NASA must address existing design and safety risks resulting from the lack of standard requirements for spacesuits to be compatible with various lunar spacecraft and assets.

As shown by the photo above, the development of Axiom’s spacesuit has been proceeding, and seems likely to be available for next year’s Artemis-3 Earth orbit test mission. At the same time, it is still behind schedule, a fact that has been mitigated because NASA’s entire Artemis program is equally behind schedule.

The report lists three commercial companies that might be able to provide alternative suits, and thus some redundancy, as shown by the image below.
» Read more

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Hubble looks at the Trifid Nebula again

9:59 am

Trifid Nebula as seen by Hubble
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken by the Hubble Space Telescope and released today. It shows a small section of the Trifid Nebula, located about 5,000 light years away.

This location has been imaged numerous times in the past by Hubble. The area shown illustrates some fundamental aspects of stellar and nebula formation. The dark area in the lower right is a thick dust cloud. Several energetic O and B supermassive stars are out of view at the top. The radiation from these stars (indicated by the blue), is hitting that dust cloud and literally destroying it. It appears that the foreground “horn” exists because a larger object is blocking the radiation, allowing dust to survive in the background.

I have no explanation for the background “horn”.

This new image was taken in parallel with an image of the entire Trifid Nebula, taken by the new Rubin Telescope in Chile. Though Rubin cannot see with the same resolution as Hubble, its image is quite worthwhile viewing.

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Final ground testing begins of Katalyst’s Swift rescue spacecraft

5:46 am

Katalyst's proposed Swift rescue mission
Katalyst’s proposed Swift rescue mission.
Click for original image.

Only seven months after NASA awarded the satellite repair startup Katalyst the contract to save the Gehrels-Swift space telescope, the company has delivered the completed LINK spacecraft to the Goddard Space Flight Center in Maryland for final ground testing.

Katalyst will move forward with LINK’s vibration and thermal tests using NASA Goddard’s in-house facilities in the coming weeks before installation into Northrop Grumman’s Pegasus rocket at the agency’s Wallops Flight Facility in Virginia.

Gehrels-Swift has been one of NASA’s most productive space telescopes. Unfortunately its orbit is decaying and if nothing is done to raise that orbit it will burn up in the atmosphere in 2029 or so. To extend this timeline engineers have stopped almost all science work in February.

Katalyst hopes to launch LINK as soon as later this year. It was able to get it built so quickly because it was already under construction as the company’s first demo of its repair technology. When NASA put out a bid for boosting Swift, the company shifted gears and reconfigured LINK for this mission.

If successfully, the achievement will be a major coup for this startup.

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Engineers shut down another instrument on Voyager-1

5:31 am

The Voyager missions
The routes the Voyager spacecraft have
taken since launch. Not to scale.

Due to the continuing and expected decline in power, engineers have now shut down another instrument on Voyager-1 in the hope of keeping the spacecraft operating for just a few more years.

On April 17, engineers at NASA’s Jet Propulsion Laboratory (JPL) in Southern California sent commands to shut down an instrument aboard Voyager 1 called the Low-energy Charged Particles experiment, or LECP. The nuclear-powered spacecraft is running low on power, and turning off the LECP is considered the best way to keep humanity’s first interstellar explorer going.

The LECP has been operating almost without interruption since Voyager 1 launched in 1977 — almost 49 years. It measures low-energy charged particles, including ions, electrons, and cosmic rays originating from our solar system and galaxy.

…The choice of which instrument to turn off next wasn’t made in the heat of the moment. Years ago, the Voyager science and engineering teams sat down together and agreed on the order in which they would shut off parts of the spacecraft while ensuring the mission can continue to conduct its unique science. Of the 10 identical sets of instruments that each spacecraft carries, seven have been shut off so far. For Voyager 1, the LECP was next on that list. The team shut off the LECP on Voyager 2 in March 2025.

Both spacecraft now have only three operating science instruments. Engineers hope a major reboot on both spacecraft planned later this year might make each operate more efficiently, allowing both to survive maybe until 2030. At a minimum the hope is to make them last until 2027, which would the fiftieth anniversary of their launch.

The bottom line remains: the nuclear power source on board both is running down. The goal now is less gathering science data and more engineering: How long can we keep these spacecraft alive, at the very outskirts of our solar system?

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The movement of surface ash on Mars over a half century

12:08 pm

Viking and Mars Express images side-by-side for comparison
Go here and here for original images.

Overview map

Cool image time! In comparing images of one location on Mars taken a half century apart, scientists using Europe’s Mars Express orbiter have discovered that the dark ash covering this region has shifted south by about 200 miles.

The two images above show the change, with a Viking orbiter image taken sometime in 1976 on the left and the Mars Express image taken in 2026 on the right. Both images have been enhanced to match each other, with the white box marking an area seen in close-up by Mars Express.

The overview map to the right provides the context. This region is inside Utopia Basin, one of the largest ancient impact basins on Mars, thought to have been formed by an impact that occurred a little more than four billion years ago. Much of Mars’ dark volcanic dust is thought to come from the Medusae Fossae Formation, a gigantic volcanic ash field the size of India and located on the other side of the planet, in between all of the red planet’s largest volcanoes. Over the eons that ash has gotten distributed across the globe.

In this case, it not only covers large areas of Utopia Basin, but over a half century the prevailing winds in the thin Martian atmosphere has been enough to shift the edge of this particular ash field south by 200 miles.

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DESI telescope completes its nominal mission, mapping more than 47 million galaxies

9:56 am

DESI map
Click for original image.

The Dark Energy Spectroscopic Instrument (DESI) on the Mayall 4-meter telescope at Kitt Peak in Arizona, in Arizona has now completed its initial five-year nominal mission, mapping more than 47 million galaxies to produce a rough 3D map of the universe.

By comparing how galaxies clustered in the past with their distribution today, researchers can trace dark energy’s influence over 11 billion years of cosmic history. Surprising results using DESI’s first three years of data hinted that dark energy, once thought to be a “cosmological constant,” might be evolving over time. With the full set of five years of data, researchers will have significantly more information to test whether that hint disappears or grows. If confirmed, it would mark a major shift in how we think about our Universe and its potential fate, which hinges on the balance between matter and dark energy.

The image to the right shows the map, with the blank areas to the left and right regions blocked by the Milky Way.

DESI will continue mapping for at least another three years, refining its data. I suspect when scientists begin analyzing this information they will find there are more than one way to interpret it.

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Scientists: First data from Europe’s Proba-3 satellites suggest the Sun’s slow solar wind is faster and more chaotic than expected

3:20 pm

Figure 4 showing variable speeds of slow solar wind
Click for original image.

The uncertainty of science: According to the first published paper [pdf] from Europe’s two Proba-3 satellites, scientists have found the slow solar wind that comes from the Sun is sometimes far faster than expected, and is also far more chaotic. From the second link above:

Just like wind on Earth, solar wind can be fast or slow, smooth or gusty. Fast solar wind usually flows in a smooth current from magnetic structures called coronal holes. In contrast, slow solar wind is variable and gusty, making understanding how it works more difficult.

Scientists think that slow solar wind is generated by the Sun’s magnetic field lines changing how they are connected, merging and separating again. This process pushes out blobs of plasma (electrically charged gas) in so-called ‘streamers’: large, bright rays in the corona.

…Previously, scientists found that close to the Sun’s surface, slow solar wind should have speeds around 100 km/s. Instead, Andrei’s team tracked some blobs of plasma moving at 250–500 km/s.

The graph to the right, Figure 4 in the paper, shows Proba-3’s tracking of a variety of these blobs. Not only did some move faster than expected (the arrows above the gray line marking earlier data), their speeds changed with time, with some actually speeding up.

The reason the Sun’s fast wind is relatively stable is that it emanates from magnetic structures dubbed coronal holes because the magnetic field lines there are is somewhat calm and stable. The slow wind meanwhile comes out through much more active and unstable regions of the magnetic field, with its field lines jumping about as well as connecting and unconnecting from the field’s structure in a chaotic manner.

This research suggests that the slow wind is chaotic and thus unpredictable, almost like the weather on Earth.

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Orion’s risky return-to-Earth happens tonight at 8:07 pm (Eastern)

9:47 am

The Earth as seen by the Artemis-2 astronauts, from behind the Moon
The Earth and Moon during the lunar fly-by on April 6, 2026.
Click for original image.

After spending ten days in space, including a swing around the back of the Moon, the four-person Artemis-2 crew is now preparing for its return-to-Earth this evening, splashing down off the Pacific coast near San Diego.

At 10:53 p.m. EDT [last night], the Orion spacecraft ignited its thrusters for 9 seconds, producing an acceleration in velocity of 5.3 feet-per-second and pushing the Artemis II crew toward Earth. The crew is now more than halfway home.

About two hours before the burn, there was an unexpected return link loss of signal during a data rate change affecting the transmission of communications and telemetry from the spacecraft to the ground. Two-way communications were reestablished, and flight controllers resumed preparing for the upcoming burn with the crew shortly after.

…The third return trajectory correction burn is scheduled for April 10 at about 1:53 p.m. ahead of re-entry procedures.

This is I think the second time Orion has had a short loss of communications with ground control. In addition, the crew had to cancel a planned manual piloting demonstration of Orion while it flew past the Moon because of a leak in an internal helium tank, used to maintain pressure in the oxygen tank as the propellant is used. The leak was inside the European-built service module, which will be jettisoned before re-entry and burn up in the atmosphere.

Mission managers say this leak has not impacted any engine burns, but it will require attention before the next flight.

The return to Earth however carries the biggest risk of the entire mission. Orion’s heat shield is questionable. During its first use in the 2022 unmanned Artemis-1 flight around the Moon, it did not behave as expected, with large chunks breaking off instead of thin layers ablating away. Though mission engineers have adjusted the flight path through the atmosphere to mitigate stress, there is great uncertainty about that solution.

I have embedded NASA’s live stream of the return-to-Earth below. It begins at 6:30 pm (Eastern), though the first return event, jettison the service module, doesn’t occur until 7:33 pm (Eastern).
» Read more

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Martian mountains on Mount Sharp

11:45 am

Panorama looking up Mount Sharp
Click for larger full resolution image. For original images go here and here.

Overview map
Click for interactive map.

Cool image time! The panorama above was created using two pictures taken by the high resolution camera on the rover Curiosity on Mars (here and here).

The overview map to the right gives the context. The blue dot marks Curiosity’s position on the day before these pictures were taken, climbing through the foothills on the flanks of Mount Sharp. I do not know if it traveled again before taking these two pictures above. The white dotted line its past travels, while the red dotted line its planned future route. At present Curiosity has climbed about 3,500 feet up the mountain. It is still about 15,000 feet below the peak, which is about 25 miles away and not visible from here.

The yellow lines indicate where I think the panorama is looking, though I admit that I am not sure. The view is distant, since this is high resolution camera. This panorama might actually be looking in a completely different direction, downhill at one of the hills that Curiosity previously drove past. The air is very dusty, which means if the rim of Gale Crater is in the background, 20-30 miles away, we can’t see it.

Regardless, the science team has finally finished its many nine-month-long survey of the boxwork geology, and has sent Curiosity climbing again. I think these pictures are part of their review of the future terrain, as they plan the rover’s route through the lighter-colored sulfate terrain higher on the mountain. If instead they are looking downhill, they were taken both to review previously viewed geology as well as to measure the dustiness of the atmosphere.

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Feathery eroding layers on Mars

11:01 am

Feathery layers on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on February 23, 2026 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team calls “layers exposed around [a] streamlined feature”.

The elevation difference between the mesa top on the left and the canyon floor on the right is about 1,000 feet. The layers are the terraces stepping downward along that drop.

What makes these layers interesting is how they have been exposed. The material that makes up the layers appears very sandy and delicate, so it breaks away it very small pieces, just like sand on a beach. The result is this feathery look. If you look close you can see that some small craters have been partly obliterated by that erosion, with their existence only marked by their remaining rim, on the high side.
» Read more

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Cracked bedrock on Mars?

2:01 pm

Cracked Martian landscape
Click for full image.

For today’s cool image we return to Mars. The picture to the right, cropped and brightened to post here, was taken on December 3, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The focus of the picture was a strange crater in the floor of Mawrth Vallis, a channel that drains northward from Mars’ cratered southern highlands to its northern lowland plains. You can see the crater in the full image if you click on the picture. It is intriguing because its rim is strangely abrupt and flat on all sides, something that is not seen with impact craters, which have a raised rim of material plowed out by the impact.

In the picture to the right I have however focused on the two small 50-70-foot-high mesas and cracked ground that surrounds them. What struck me was the dry appearance of this landscape. Located at 23 degrees north latitude, it is in the dry tropics of Mars, where little near surface ice is found. The cracks emphasize this conclusion, as they so well resemble the cracks you see in dried mud on Earth.
» Read more

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Voyager-2’s most detailed look at Neptune’s moon Triton

3:10 pm

Triton
Click for original image.

Today we conclude our tour of the Voyager-2 fly-bys of Uranus in 1986 and Neptune in 1989 with what is the most detailed look at the alien surface of Neptune’s moon Triton, taken on August 25, 1989 and shown to the right, cropped, rotated, reduced, and sharpened to post here.

Taken from a distance of only 25,000 miles, the frame is about 140 miles across and shows details as small as [a half mile in width]. Most of the area is covered by a peculiar landscape of roughly circular depressions separated by rugged ridges. This type of terrain, which covers large tracts of Triton’s northern hemisphere, is unlike anything seen elsewhere in the solar system. The depressions are probably not impact craters: They are too similar in size and too regularly spaced. Their origin is still unknown, but may involve local melting and collapse of the icy surface.

A conspicuous set of grooves and ridges cuts across the landscape, indicating fracturing and deformation of Triton’s surface. The rarity of impact craters suggests a young surface by solar system standards, probably less than a few billion years old.

What this photograph as well as the handful of other Voyager-2 images of Triton tell us is that we only have gotten a tiny taste of what’s there, only enough to tell us we don’t understand what we are seeing in the slightest. This is a truly alien world, cold, dark, and composed of materials far different then that found in the inner solar system. Its formation is a mystery, and its subsequent geological history a cypher. Scientists have made some guesses, but to get a real understanding we need to go back, and be there for a long time.

In fact, this is the final conclusion of all of the Voyager-2 images from both Uranus and Neptune. That probe gave humanity its first good close look at these distant worlds, but the look was still a quick and very superficial one. The images and data left us with far more questions than answers.

Unfortunately, there is at present no mission approved and under development to go to either Uranus or Neptune, though several have been proposed. Thus, it will likely be at least two decades before any mission gets there, if that soon.

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Neptune’s rings, as seen by Voyager-2 in 1989

2:05 pm

The rings of Neptune as seen by Voyager-2
Click for original image.

Cool image time! The picture to the right, cropped, reduced slightly, and sharpened to post here, was taken by Voyager-2 on August 26, 1989 shortly after it had completed its close fly-by of Neptune, looking back at the planet from a distance of about 175,000 miles.

The two main rings are clearly visible and appear complete over the region imaged. … Also visible in this image is the inner faint ring at about 25,000 miles from the center of Neptune, and the faint band which extends smoothly from the 33,000 miles ring to roughly halfway between the two bright rings. Both of these newly discovered rings are broad and much fainter than the two narrow rings.

These long exposure images were taken while the rings were back-lighted by the sun at a phase angle of 135 degrees. This viewing geometry enhances the visibility of dust and allows fainter, dusty parts of the ring to be seen. The bright glare in the center is due to over-exposure of the crescent of Neptune. The two gaps in the upper part of the outer ring in the image on the left are due to blemish removal in the computer processing. Numerous bright stars are evident in the background. Both bright rings have material throughout their entire orbit, and are therefore continuous.

While Voyager-2 took other pictures of these rings (here, here, here, here, and here), I think this picture shows the rings best, if not terrible well. Images using the Hubble and Webb space telescopes as well as others have not been better.

The rings were first confirmed to exist in the mid-1980s, shortly before Voyager-2’s fly-by. We now think there are five rings total, all made of dark material, likely a mix of carbon-based molecules, much of it the equivalent of dust and soot.

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The new Rubin telescope discovers over 11,000 new asteroids in first observations

11:07 am

Rubin's first asteroid discoveries
Click for full animation.

The new Rubin Observatory, a ground-based telescope in Chile, has discovered over 11,000 new asteroids in its first preliminary observations, with most in the main asteroid belt but a large number in the Kuiper Belt beyond Neptune and 33 previously unknown near-Earth asteroids.

The graphic to the right, annotated by me to post here, shows all of Rubin’s asteroid detections in light blue.

The submission to MPC [Minor Planet Center] comprises approximately one million observations, taken over the span of a month and a half, of over 11,000 new asteroids and more than 80,000 already known asteroids, including some that had previously been observed but were later “lost” because their orbits were too uncertain to predict their future locations. You can interact with all of Rubin’s asteroid discoveries in the Rubin Orbitviewer, which uses real data to provide an intuitive way to explore the structure of our cosmic backyard in three dimensions and in real time. Also, visit the Rubin Asteroid Discoveries Dashboard to learn about the new objects Rubin has uncovered.

…Among the newly identified objects are 33 previously unknown near-Earth objects (NEOs), which are small asteroids and comets whose closest approach to the Sun is less than 1.3 times the distance between Earth and the Sun. None of the newly discovered NEOs pose a threat to Earth, and the largest is about 500 meters wide.

Astronomers predict that Rubin will eventually find 90,000 new near-Earth objects, with some expected to pose a risk of hitting the Earth. It does this by repeatedly surveying the southern sky with its large mirror, then identifying new objects with its sophisticated software.

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Voyager-2 discovered Neptune to be a planet of quickly changing weather

10:53 am

Neptune's fast changing weather
Click for source.

Cool image time! When Voyager-2 flew past Uranus in 1986, the data showed the gas giant’s weather to be relatively sedate and quiet, with little changing during the fly-by. Scientists expected this: Uranus’s distance from the Sun meant it got little energy to fuel an active climate, with any activity produced by internal heating due to the gravitational pressure of its mass. And Uranus did not produce that much heat internally.

When Voyager-2 passed Neptune three year later, the scientists expected something similar, or even less, due to Neptune’s greater distance from the Sun. Instead, Voyager-2’s data showed Neptune’s weather patterns to be changing constantly and quickly, as illustrated by the three images of the Great Dark Spot to the right, the biggest storm on Neptune at that time and located in the planet’s southern mid-latitudes.

The bright cirrus-like clouds of Neptune change rapidly, often forming and dissipating over periods of several to tens of hours. In this sequence spanning two rotations of Neptune (about 36 hours) Voyager 2 observed cloud evolution in the region around the Great Dark Spot at an effective resolution of about 60 miles per pixel. The surprisingly rapid changes which occur over the 18 hours separating each panel shows that in this region Neptune’s weather is perhaps as dynamic and variable as that of the Earth. However, the scale is immense by our standards — the Earth and the [Great Dark Spot] are of similar size.

In Neptune’s frigid atmosphere, where temperatures are as low as 55 degrees Kelvin (-360 F), the cirrus clouds are composed of frozen methane rather than Earth’s crystals of water ice.

Subsequent observations by the Hubble Space Telescope in 1994 found this Great Dark Spot was gone, replaced by a comparable storm in the northern hemisphere. Further Hubble observations found Neptune’s storms tend to last about two years, fading as they drifted towards the equator. Those observations however also detected storms drifting away from the equator. Other research suggested the storms might be influenced by the Sun’s sunspot cycle.

All of the data post-Voyager-2 remains very coarse and uncertain, as we are looking at Neptune at a great distance. Thus, no theory about what is happening carries much weight, especially because we do not know why Neptune produces so much more internal heat than Uranus, fueling this fast-changing weather. For example, Neptune gets 1/20th of the energy received by Jupiter, yet its atmosphere appears even more active and variable.

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Voyager-2’s view of clouds on top of clouds on Neptune

11:45 am

Neptune's upper clouds
Click for original image.

Time to continue our cool image tour this week of the Voyager-2 archive of Neptune, taken during the spacecraft’s August 25, 1989 close fly-by of the gas giant, zipping only 2,700 miles above the cloud-tops. This remains the only mission to visit Neptune so far.

The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken two hours before Voyager-2’s closest approach. From the caption:

These clouds were observed at a latitude of 29 degrees north near Neptune’s east terminator. The linear cloud forms are stretched approximately along lines of constant latitude and the sun is toward the lower [right]. The bright sides of the clouds which face the sun are brighter than the surrounding cloud deck because they are more directly exposed to the sun. Shadows can be seen on the side opposite the sun.

These shadows are less distinct at short wavelengths (violet filter) and more distinct at long wavelengths (orange filter). This can be understood if the underlying cloud deck on which the shadow is cast is at a relatively great depth, in which case scattering by molecules in the overlying atmosphere will diffuse light into the shadow. Because molecules scatter blue light much more efficiently than red light, the shadows will be darkest at the longest (reddest) wavelengths, and will appear blue under white light illumination.

The resolution of this image is 6.8 miles per pixel and the range is only 98,000 miles. The width of the cloud streaks range from 30 to 125 miles, and their shadow widths range from 18 to 30 miles. Cloud heights appear to be of the order of 31 miles.

Of all the high resolution images taken of Neptune by Voyager-2, this is the only one that clearly shows some dimensionality. Later photographs taken by Hubble and other ground- and space-based telescopes can only show global views that are far less sharp than the global views produced by Voyager-2.

This picture hints at Neptune’s very complex weather patterns, which has no well-defined surface and is made up mostly of gas and liquid. Though scientists have used Hubble to roughly track those weather patterns, they can only glean the most basic facts. For example, its fast-changing weather appears to be driven by high winds, thought to move as fast as 1,300 miles per hour. This fact however is woefully incomplete and very uncertain, as we have no way to track detailed weather patterns at multiple depths.

Our tour will continue tomorrow.

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A soft barred galaxy with an active nucleus

9:56 am

A barred galaxy with an active galactic nucleus
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope as part of two different surveys aimed at studying galaxies with what scientists call active galactic nuclei.

IC 486 lies right on the edge of the constellation Gemini (the Twins), around 380 million light-years from Earth. Classified as a barred spiral galaxy, it features a bright central bar-shaped structure from which its spiral arms unfurl, wrapping around the core in a smooth, almost ring-like pattern.

…At the galaxy’s center a noticeable white glow outshines the starlight around it. This is light given off by IC 486’s active galactic nucleus (AGN), powered by a supermassive black hole more than 100 million times the mass of the Sun. Every sufficiently large galaxy hosts a supermassive black hole at its center, but some of these black holes are particularly ravenous, marshaling vast amounts of gas and dust into swirling accretion discs from which they feed. The intense heat generated by the orbiting disc of material generates intense radiation up to and including X-rays, which can outshine the entire rest of the galaxy. In these cases, the galaxy is known as an active galaxy, with an AGN at its center.

For comparison, the relatively inactive supermassive black hole at the center of the Milky Way has a mass of about four million Suns, considerably smaller than IC 486’s. Why one is active and the other not however is not yet truly understood, though their different masses might provide part of the explanation.

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Neptune as seen by Voyager-2 in 1989, four days before closest approach

2:46 pm

Neptune as seen by Voyager-2 on approach
Click for original image.

Cool image time! In two earlier posts I highlighted the pictures taken by Voyager-2 of Neptune’s two largest moons, Triton and Proteus, when it made its close fly-by of Neptune in 1989. Other than a very distant low resolution picture of 105-mile-wide Nereid, Voyager-2 took no other good images of Neptune’s other known moons.

So today, let’s begin a tour of some of Voyager-2’s imagery of Neptune itself. The picture to the right, reduced slightly to post here, was taken on August 20, 1989 as the spacecraft was beginning its approach to Neptune. It shows the full daylight hemisphere of the gas giant. From the caption:

The images were taken at a range of 4.4 million miles from the planet, 4 days and 20 hours before closest approach. The picture shows the Great Dark Spot and its companion bright smudge; on the west limb the fast moving bright feature called Scooter and the little dark spot are visible. These clouds were seen to persist for as long as Voyager’s cameras could resolve them. North of these, a bright cloud band similar to the south polar streak may be seen.

Next week I will post some of the other good shots taken of Neptune, as well as one or two close-ups of Triton that need highlighting. Sadly, at that point we will have more or less reviewed most of the best data now available of this distant world. Astronomers have used the Hubble Space Telescope in subsequent years to attempt to track its weather patterns, but even Hubble really can’t provide enough resolution to really make that research substantive.

But stay tuned. The Voyager-2 images to come are worth viewing.

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Ispace to replace engine on its lunar lander, delaying its NASA mission to 2030

9:09 am

Ispace's old and new landers

The Japanese lunar lander startup Ispace has been forced to institute a major shake-up of its upgraded lunar lander design because a subcontractor’s engine did not meet the required specifications.

The engine, called Voidrunner and built by Agile Space Industries, was about to be installed in the lander for a 2027 launch of NASA lunar lander mission when a review found its performance to be unsatisfactory.

After closely monitoring the engine’s status and conducting careful review, Ispace has determined that a change in the development plan to incorporate a new alternative engine is necessary to ensure the successful execution of the lunar landing mission. The new engine, which will replace VoidRunner, has already been developed by the alternative supplier and has a proven track record of operation in past lunar missions.

The company has also decided to standardize its two lunar lander designs, one developed in Japan and the second in parallel by its American division. The new lander, dubbed Ultra, will use this new engine and fly all of Ispace’s subsequent missions. The image above shows the company’s original lander Hakuto-R on the left, compared to its new Ultra lander on the right.

This change will delay its planned NASA mission by three years, to 2030, though the company hopes it will not impact the schedule of two other lunar lander missions for Japan. Its new updated schedule, all using Ultra:

  • 2028: a Japanese mission funded by Japan’s Ministry of Economy, Trade and Industry
  • 2029: a Japanese mission funded by Japan’s Space Strategy Fund (designed at encouraging the private space sector
  • 2030: NASA’s mission, being built in partnership with the American company Draper

Ispace has also created a new lunar satellite program, to provide communications, location data, and satellite tracking from lunar orbit, with a goal of launching its first lunar orbiter by next year, and five by 2030.

As a lunar lander company Ispace has had a very mixed record. It has successfully flown two landers to lunar orbit and then down to the surface. Each however crashed, failing just prior to landing due to software issues. This new delay of its NASA mission is not going to please NASA administrator Jared Isaacman, who instead wants to speed up the agency’s lunar lander program, flying almost monthly beginning in 2030. It likely means Ispace is going to have problems winning any new NASA lander contracts, until it proves its new Ultra lander design.

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Proteus, Neptune’s second largest moon, discovered by Voyager-2 in 1989

3:02 pm

Proteus, Neptune's second largest moon
For original images go here and here.

Our tour continues of the only close visit to Neptune on August 25, 1989 by Voyager-2. The two pictures to the right were taken by the spacecraft during that fly-by of Neptune’s second largest moon, dubbed Proteus. Both pictures are shown as Voyager-2 took them.

The top picture was taken from a distance of about 540,000 miles, and has a resolution of about five miles per pixel.

The satellite has an average radius of about 120 miles and is uniformly dark with an albedo of about 6 percent. The irregular shape suggests that 1989N1 has been cold and rigid throughout its history and subject to significant impact cratering.

The bottom picture was taken from a distance of about 91,000 miles, and can resolve objects as small as 1.7 miles in size.

Hints of crater-like forms and groove-like lineations can be discerned. The apparent graininess of the image is caused by the short exposure necessary to avoid significant smear.

Proteus was not known prior to Voyager-2’s fly-by, because it orbits so close to Neptune (about 73,000 miles) that the ground-based telescopes of the time could not see it in the glare of the gas giant. It was discovered in early global pictures of Neptune as Voyager-2 approached.

While planetary scientists have made some educated guesses about the moon’s origin and geology based on these two images, they are simply guesses. These are the only detailed images we have of Proteus, and neither is particularly good.

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Webb and Hubble take a look at Saturn

9:37 am

Saturn seen by Webb and Hubble

Astronomers using both the Hubble Space Telescope and the Webb Space Telescope have produced new complementary views of the ringed planet Saturn.

Those photographs are shown above, with Webb’s false-color infrared image to the left and Hubble’s optical image to the right. From the press release:

In the Webb image, a long-lived jet stream known as the “ribbon wave” meanders across the northern mid-latitudes, influenced by otherwise undetectable atmospheric waves. Just below that, a small spot represents a lingering remnant from the “Great Springtime Storm” of 2010 to 2012. Several other storms dotting the southern hemisphere of Saturn are visible in Webb’s image, as well. All these features are shaped by powerful winds and waves beneath the visible cloud deck, making Saturn a natural laboratory for studying fluid dynamics under extreme conditions.

…In Webb’s infrared image, the rings are extremely bright because they are made of highly reflective water ice. In both images, we’re seeing the sunlit face of the rings, a little less so in the Hubble image, hence the shadows visible underneath on the planet.

There are also subtle ring features such as spokes and structure in the B ring (the thick central region of the rings) that appear differently between the two observatories. The F ring, the outermost ring, looks thin and crisp in the Webb image, while it only slightly glows in the Hubble image.

The press release says little about the Hubble image, mostly because it shows little new by itself. It however is part of an on-going decade-long survey using Hubble to track Saturn’s changing weather patterns.

While both images are valuable, they also highlight our present limits in observing Saturn. Views from Earth can only see so much. It is like trying to watch a football game from ten miles away, with binoculars. And sadly, no mission is presently planned to return to Saturn.

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Triton: Neptune’s largest moon

11:19 am

The southern mid-latitudes of Neptune's moon Trident
Click for original image.

Triton

Today’s cool image begins a new tour I plan on doing over the next week or so of the few close-up photographs we have of Neptune and its moons, sent back by Voyager-2 when it did its close fly-by of this distant planet on August 25, 1989. That fly-by was almost 37 years ago, and it remains our only close look. While at the time it shined a quick flashlight of new knowledge on Neptune, its moons, and its ring system, we remain generally in the dark about what’s there, despite some good imagery produced in subsequent years by Hubble and some ground-based telescopes.

The image above, cropped and enhanced to post here, shows a portion of the southern mid-latitudes of Triton, Neptune’s largest moon, as Voyager-2 made its closest pass at a distance of about 25,000 miles. The photo to the right, cropped and reduced, shows a more global view to provide some context, with the box indicating the approximate area covered by the upper image. It was taken when Voyager-2 was on approach, at a distance of about 330,000 miles. The top picture captures several dozen black plumes that appear to vent material from below. From the caption:

The plumes originate at very dark spots generally a few miles in diameter and some are more than 100 miles long. The spots which clearly mark the source of the dark material may be vents where gas has erupted from beneath the surface and carried dark particles into Triton’s nitrogen atmosphere. Southwesterly winds then transported the erupted particles, which formed gradually thinning deposits to the northeast of most vents.

It is possible that the eruptions have been driven by seasonal heating of very shallow subsurface deposits of volatiles, and the winds transporting particles similarly may be seasonal winds. The polar terrain, upon which the dark streaks have been deposited, is a region of bright materials mottled with irregular, somewhat dark patches. The pattern of irregular patches suggests that they may correspond to lag deposits of moderately dark material that cap the bright ice over the polar terrain.

As we only have a few images of this planet, and those provided views of only about 40% of its surface, any theory that tries to explain the weird geology here is certain to be wrong to some degree.

More to come in the next few days. As much as we think we know, these pictures are going instead highlight how sparse that knowledge really is.

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Intuitive Machines wins $180.4 million new NASA lunar lander contract

8:46 am

Intuitive Machines' Nova-D lunar lander
Click for original.

The lunar lander startup Intuitive Machines announced yesterday that it has won its fifth contract from NASA, a $180.4 million deal to place its larger upgraded Nova-D lander near the Moon’s south pole.

The IM-5 mission will target Mons Malapert, a ridge near the Lunar South Pole that offers continuous Earth visibility, stable illumination conditions, and access to permanently shadowed regions. These characteristics make the site a compelling location for future communications, navigation, and surface infrastructure.

The artist’s rendering to the right shows this Nova-D lander. What stands out immediately is its low-slung appearance. Intuitive Machines’ smaller Nova-C lander was tall (see this image), with a high center of gravity. In its only two landing attempts on the Moon it tipped over both times after touchdown. It appears the company has finally recognized the issue and reworked this new lander to make it more stable after touchdown.

This contract award appears to be part of the accelerated program by NASA administrator Jared Isaacman to land 30 unmanned rovers on the moon in three years, beginning in 2027. Mons Malapert is a plateau that Intuitive Machines second lander tipped over on. It is also the landing site for Astrobotics’ Griffin lander, as well as a candidate landing site for the first Artemis manned missions.

Note the small rover on the right in the graphic. While the mission will carry seven NASA science instrument payloads, it will also carry this commercial rover, built by Honeybee Robotics, a subsidiary of Blue Origin. As the company states above, the lander on this mission also has additional available payload capacity for more commercial customers.

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