Tag Archives: asteroids

OSIRIS-REx unfolds its robot arm

In preparation for its December 3 rendezvous with the asteroid Bennu OSIRIS-REx successfully unfolded its robot arm for the first time since launch this week.

The website has a nice short video showing how the arm will grab its samples. Very innovative, and not what you would expect. The technique had to be clever because Bennu is so small and has such a tiny gravity.

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Scientists discover giant impact crater buried under Greenland ice

Scientists have discovered the existence of a giant impact crater buried under the Greenland ice.

An international team of researchers, including a NASA glaciologist, has discovered a large meteorite impact crater hiding beneath more than a half-mile of ice in northwest Greenland. The crater — the first of any size found under the Greenland ice sheet — is one of the 25 largest impact craters on Earth, measuring roughly 1,000 feet deep and more than 19 miles in diameter, an area slightly larger than that inside Washington’s Capital Beltway.

They think, based on the data, that this crater is very young, one of the youngest known on Earth. At the most is is no more than 3 million years old.

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Null result from Spitzer suggests Oumuamua was small

The uncertainty of science: The inability of the infrared Spitzer Space Telescope to detect the interstellar object Oumuamua as it exited the solar system suggests the object is small.

The fact that ‘Oumuamua was too faint for Spitzer to detect sets a limit on the object’s total surface area. However, since the non-detection can’t be used to infer shape, the size limits are presented as what ‘Oumuamua’s diameter would be if it were spherical. Using three separate models that make slightly different assumptions about the object’s composition, Spitzer’s non-detection limited ‘Oumuamua’s “spherical diameter” to 1,440 feet (440 meters), 460 feet (140 meters) or perhaps as little as 320 feet (100 meters). The wide range of results stems from the assumptions about ‘Oumuamua’s composition, which influences how visible (or faint) it would appear to Spitzer were it a particular size.

The new study also suggests that ‘Oumuamua may be up to 10 times more reflective than the comets that reside in our solar system – a surprising result, according to the paper’s authors.

These results fit the models that explain Oumuamua’s fluctuations in speed as caused by the out gassing of material, like a comet. They also do not contradict the recent hypothesis that the object might have been an alien-built light sail.

The simple fact is that we do not have enough data to confirm any of these theories.

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Bennu’s two hemispheres

Bennu's two hemispheres

The image above of the two hemispheres of the asteroid Bennu, cropped and reduced very slightly to post here, was created from several images taken by OSIRIS-REx on two different days last week.

These two super-resolution views of asteroid Bennu were created using eight 2.5-millisecond exposure images captured by OSIRIS-REx on two separate days. The view on the left is composed of eight PolyCam images taken over the span of two minutes on Nov. 1, 2018, when the spacecraft was about 126 miles (203 km) from the asteroid. The one on the right – showing the opposite side of the asteroid – was generated using eight images taken during the same two-minute time slot on Nov. 2, from a distance of about 122 miles (196 km).

The rock on the southern limb is the same in both images, merely seen from opposite sides. Bennu appears very similar to Ryugu, except that there do appear to be dark areas on its surface, possibly crater sites, that might be smooth enough for landing.

The rendezvous at Bennu will occur on December 3.

UPDATE: The OSIRIS-REx science team has now released a short movie showing Bennu’s rotation as imaged during this same time period.

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Dawn’s last look at Ceres

Ceres

The Dawn mission has ended, and the image on the right, reduced to post here, is one of its last views of Ceres, with the bright spots of Occator Crater clearly visible, before its fuel ran out. You can see the full resolution image by clicking on the image.

This photo of Ceres and the bright regions in Occator Crater was one of the last views NASA’s Dawn spacecraft transmitted before it depleted its remaining hydrazine and completed its mission.

This view, which faces south, was captured on Sept. 1, 2018 at an altitude of 2,340 miles (3,370 kilometers) as the spacecraft was ascending in its elliptical orbit. At its lowest point, the orbit dipped down to only about 22 miles (35 kilometers), which allowed Dawn to acquire very high-resolution images in this final phase of its mission. Some of the close-up images of Occator Crater are shown here.

Occator Crater is 57 miles (92 kilometers) across and 2.5 miles (4 kilometers) deep and holds the brightest area on Ceres, Cerealia Facula in its center and Vinalia Faculae in its western side. This region has been the subject of intense interest since Dawn’s approach to the dwarf planet in early 2015.

If NASA made any specific announcement about the end of the mission, I have missed it. Either way, this end is not a surprise, because they have made it clear for the past few months that the spacecraft was about to run out of fuel.

They have also posted today an image of Ceres’ largest mountain, Ahuna Mons.

Update: Even as I posted this, NASA sent out this press release: NASA’s Dawn mission comes to an end

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OSIRIS-REx snaps image of target asteroid Bennu

Bennu

OSIRIS-REx has snapped its sharpest image yet of its target asteroid Bennu, set for a rendezvous on December 3. The image on the right is that image, at full resolution but cropped.

This “super-resolution” view of asteroid Bennu was created using eight images obtained by NASA’s OSIRIS-REx spacecraft on Oct. 29, 2018 from a distance of about 205 miles (330 km). The spacecraft was moving as it captured the images with the PolyCam camera, and Bennu rotated 1.2 degrees during the nearly one minute that elapsed between the first and the last snapshot. The team used a super-resolution algorithm to combine the eight images and produce a higher resolution view of the asteroid. Bennu occupies about 100 pixels and is oriented with its north pole at the top of the image.

It is beginning to appear that the OSIRIS-REx engineering team is going to have the same kind of problems now faced by the Hayabusa-2 engineering team. In this first glance Bennu appears very similar to Ryugu, a rubble pile shaped approximately like a box, rotating on one point. If so, they are also going to find it difficult to locate a smooth landing site.

Bennu by the way is in an orbit that makes a collision with the Earth possible in the late 22nd century. Knowing its composition, density, and solidity is critical for determining what to do, should that collision become likely.

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Oblique view of Hayabusa-2’s most recent landing rehearsal

Cool movie time! The Hayabusa-2 science team has released a small movie of images taken by a side-mounted camera of the spacecraft’s most recent landing rehearsal, showing the spacecraft ascend from its closest approach from an oblique angle.

I have embedded the movie from these images below the fold. As they note,

Images taken with the small monitor camera (CAM-H) during the Touchdown 1 Rehearsal 3 operation (TD1-R3). One image was captured every second from immediately after the spacecraft began to ascend (altitude 21m) on October 25, 2018 at 11:47 JST. The spacecraft was rising at about 52cm/s.

It appears the closest image was taken from about 21 meters away, about 65 feet, and gives a sense of scale. It also reveals once again how difficult that landing in January is going to be. Though this location is thought to be the smoothest spot on Ryugu, it is still littered with rocks that could cause problems.
» Read more

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Hayabusa-2’s highest resolution image so far

Ryugu up close

The Hayabusa-2 science team has released the highest resolution image taken by the spacecraft so far. The image on the right, reduced to post here, is that image. Click on it to see the full resolution version.

The image resolution is about 4.6mm/pixel. This is the highest resolution image that Hayabusa2 has taken so far and even small rocks with a diameter of 2 – 3cm are clearly visible. The maximum resolution of AMICA –the camera at the time of the first Hayabusa mission— was 6 mm/pixel, so even its resolution has now been exceeded. As the image captured of the asteroid surface from the spacecraft, it will be one of the highest resolution to be taken of Ryugu (MINERVA-II1 and MASCOT which landed on the surface, have captured even higher resolution images).

A feature from the image is the lack of regolith (sandy substance). This was suspected to be true from the images obtained so far, but it is more clearly seen in this high resolution photograph. There is also a collection of pebbles with different colors, which may be evidence that the surface material of Ryugu is mixed.

This was taken during the second landing rehearsal about two weeks ago. The image clearly shows the rubble pile that is Ryugu, lacking anything but cemented rocks. It also illustrates the landing problem faced by Hayabusa-2’s engineers. They need a flat smooth area to land, and they have not really found one that fits their needs.

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Hayabusa-2 completes third Ryugu touchdown rehearsal

Ryugu up close

Hayabusa-2 today completed its third Ryugu touchdown rehearsal.

According to their operation schedule, they were planning to descent to about 20 meters of the surface, about 65 feet. The image on the right is the closest image taken during the rehearsal. You can see the shadow of Hayabusa-2 in the middle of the frame.

They have not released any information about the rehearsal results. The key here is how accurately they were able to get Hayabusa-2 to approach the asteroid’s largest flat spot, a tiny 20 meter wide spot less than half the size of their original planned landing diameter. From the image, it is unclear how successful they were.

They will now spend the next two months analyzing the data from their landing rehearsals in preparation for a landing attempt in January. During this time observations will be reduced because the Sun will be between the Earth and the asteroid.

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Pluto orbiter mission could also explore Kuiper belt

An analysis by scientists of the orbital mechanics surrounding Pluto and Charon, combined with the use of an ion engine similar to that used by the asteroid probe Dawn, suggests that an orbiter sent to Pluto could also break from from that planet to travel out into the Kuiper Belt and explore additional objects there.

The team first discovered how numerous key scientific objectives can be met using gravity assists from Pluto’s giant satellite, Charon, rather than propellant, allowing the orbiter to change its orbit repeatedly to investigate various aspects of Pluto, its atmosphere, its five moons, and its solar wind interactions for up to several years. The second achievement demonstrates that, upon completing its science objectives at Pluto, the orbiter can then use Charon’s gravity to escape the system without using fuel, slinging the spacecraft into the Kuiper Belt to use the same electric propulsion system it used to enter Pluto orbit to then explore other dwarf planets and smaller Kuiper Belt bodies.

“This is groundbreaking,” said Stern. “Previously, NASA and the planetary science community thought the next step in Kuiper Belt exploration would be to choose between ‘going deep’ in the study of Pluto and its moons or ‘going broad’ by examining smaller Kuiper Belt objects and another dwarf planet for comparison to Pluto. The planetary science community debated which was the right next step. Our studies show you can do both in a single mission: it’s a game changer.”

The key here is a willingness to make increased use of the ion-type engine used by Dawn in its journey from the asteroids Vesta and Ceres. Such a probe could spend decades traveling from one Kuiper Belt object to the next.

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Hayabusa-2 will do two touchdown rehearsals prior to landing in January

In order to test whether they can bring Hayabusa-2 down to the surface within a circle only 20 meters (65 feet) across (the largest smooth landing area they have found so far on Ryugu), their engineering team has decided to first do two more touchdown rehearsals in October.

In the area where the spacecraft will touchdown, it is dangerous to have boulders with a height greater than about 50cm. Since the length of the sampler horn is about 1m and the spacecraft will be to be slightly inclined during the touchdown, there is a possibility that if a boulder with a height above about 50cm is present, it will strike the main body of the spacecraft or the solar panels. Viewed from the position in Figure 2, there is no boulder larger than 50cm in the area L08-B. L08-B is the widest part within all the candidate sites without a boulder larger than 50cm.

The difficulty is that area L08-B is only about 20m in diameter. Originally, it was assumed that a safe region for touchdown would be a flat area with a radius of about 50m (100m in diameter). This has now become a radius of just 10m; a fairly severe constraint. On the other hand, during the descent to an altitude of about 50m during the MINERVA-II1 and MASCOT separation operations, we were able to confirm that the spacecraft can be guided within a position accuracy of about 10m for a height 50m above the surface of Ryugu (Figure 3). This is a promising feature for touchdown.

Although the spacecraft can be controlled with a position error of 10m at an altitude down to 50m, there remains the question of whether this accuracy can be retained as the spacecraft descends to the surface. This must be confirmed before touchdown operations. Therefore, the touchdown itself will be postponed until next year, during which time we will have two touchdown rehearsals; TD1-R1-A and TD1-R3.

After the rehearsals in October they must wait until January to do the landing because in November and December the sun will be in-between the Earth and the spacecraft, making operations more difficult. They want to also use this time to review the results of the rehearsals to better prepare for the January landing.

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MASCOT’s journey on Ryugu

MASCOT's journey on Ryugu

MASCOT’s German science team has released a summary of the lander/hopper’s results and seventeen hour journey across the surface of the asteroid Ryugu. The image on the right, reduced and cropped to post here, shows the spacecraft approach, landing, and numerous hops across the surface. If you click on the image you can see the full high resolution image.

Having reconstructed the events that took place on asteroid Ryugu, the scientists are now busy analysing the first results from the acquired data and images. “What we saw from a distance already gave us an idea of what it might look like on the surface,” reports Ralf Jaumann from the DLR Institute of Planetary Research and scientific director of the MASCOT mission. “In fact, it is even crazier on the surface than expected. Everything is covered in rough blocks and strewn with boulders. How compact these blocks are and what they are composed of, we still do not know. But what was most surprising was that large accumulations of fine material are nowhere to be found – and we did not expect that. We have to investigate this in the next few weeks, because the cosmic weathering would actually have had to produce fine material,” continues Jaumann.

The spacecraft apparently bounced eight times after first contact, then executed three hops. The rubble pile nature that is observed I think explains why the Hayabusa-2 science team decided to delay its own landing for a few months so they could figure out a plan. It really appears that Ryugu does not have any smooth flat spots, as expect.

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Hayabusa-2 landing on Ryugu delayed until January

Because of the roughness of the surface of Ryugu, the Hayabusa-2 science team has decided to delay the landing of the spacecraft on the asteroid from the end of this month until late January at the earliest.

JAXA project manager Yuichi Tsuda said they needed more time to prepare the landing as the latest data showed the asteroid surface was more rugged than expected.

“The mission … is to land without hitting rocks,” Tsuda said, adding this was a “most difficult” operation. “We had expected the surface would be smooth … but it seems there’s no flat area.”

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This decision is a wise one. They will have the ability to land very precisely, and this will give them time to find the least risky spot. It does indicate however that the landing itself is going to be risky, which is probably why they want more time to gather data beforehand. Should the landing fail, the mission will essentially be over. This way they can maximize what they learn.

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Ceres’s poles have shifted by as much as 36 degrees

A new analysis of Dawn data suggests that the poles of Ceres have wandered by as much as 36 degrees, and the data also adds further support for the existence of a liquid water layer between the dwarf planet’s crust and mantle.

“The most surprising aspect of this paper is to me the observation that the pole of Ceres must have followed an indirect path to its current pole. A multi-step reorientation could mean that the equatorial density anomaly was still evolving during the reorientation, and this could be because the crust and mantle were weakly rotationally coupled, allowing the crust to start reorienting while the mantle would lag behind,” Tricarico said. “If crust and mantle are allowed to shift with respect to one another, that could point to a layer of reduced friction between crust and mantle, and one of the possible mechanisms to reduce friction could be an ancient water ocean beneath the crust.”

In other words, the crust and mantle are not locked together. Imagine a baseball where the ballcover is not tightly held to the inner core, and slides around it. (Boy there are a lot of pitchers who wish they could get a hand on that baseball.) The cause of that looseness on Ceres is possibly because of a liquid layer in-between the crust and the mantle.

Need I note that there are uncertainties here?

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Sixth biggest Michigan meteorite discovered as doorstop

The sixth biggest Michigan meteorite ever discovered had been used as a doorstop for decades and was only identified when its present owner got curious and had it inspected by scientists.

Central Michigan University says Thursday that the 22.5-pound space rock was recently identified by Department of Earth and Atmospheric Sciences professor Dr. Monaliza Sirbescu after the owner “brought it to her out of curiosity.” The Grand Rapids man was apparently inspired to investigate after seeing news of meteorite hunters finding shards and selling them for thousands of dollars after a meteor sighting in January in the Detroit area.

The chunk of iron and nickel was later valued at $100,000 after the Smithsonian Institution verified the find, CMU said in a release. The rock, which was initially used as a doorstop in the Edmore area for several decades after a farmer recovered it sometime in the 1930s, turned out to be Michigan’s sixth-largest meteorite, a university spokesperson said.

Hat tip Wayne DeVette.

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Images of Mascot by Hayabusa released

MASCOT descending towards Ryugu

The Hayabusa-2 science team today released images taken of MASCOT as it descended to the surface of Ryugu, including images showing where it landed.

In the image on the right, reduced slightly to post here, you can see MASCOT as it slowly moves downward towards the asteroid shortly after its release from Hayabusa-2. At the link there is another image showing the mini-lander as a white dot when it was still about 115 feet above the surface. Other images show its location on the surface where it operated for seventeen hours and completed three hops.

The next big event from Hayabusa-2 will be the spacecraft’s own landing, sometime later this month.

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New Horizons makes final big course correction

New Horizons this week successfully made its final major course correction in preparation for its January 1st fly-by of the Kuiper Belt object the science team has dubbed Ultima Thule.

NASA’s New Horizons spacecraft carried out a short engine burn on Oct. 3 to home in on the location and timing of its New Year’s flyby of the Kuiper Belt object nicknamed Ultima Thule.

Word from the spacecraft that it had successfully performed the 3½-minute maneuver reached mission operations at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, at around 10:20 p.m. EDT. The maneuver slightly tweaked the spacecraft’s trajectory and bumped its speed by 2.1 meters per second – just about 4.6 miles per hour – keeping it on track to fly past Ultima (officially named 2014 MU69) at 12:33 am EST on Jan. 1, 2019.

As the spacecraft gets closer they will do more refinements, but right now they are a very precise course. The January 1st fly-by will end a spectacular fall season of planetary mission rendezvous, landings, fly-bys and sample gatherings.

Posted from Chicago.

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MASCOT ends its mission on Ryugu, as planned

Hayabusa-2’s mini-lander MASCOT has ended its mission on Ryugu after seventeen hours, slightly longer than the planned sixteen hours.

The lander made one hop, and successfully transmitted all its data back to Hayabusa-2, which still has one more mini-lander on board that will be sent to Ryugu’s surface, probably after Hayabusa-2 makes its own landing.

Meanwhile, the two Minerva-2 bouncers continue to operate on Ryugu.

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Astronomers discover very distant object orbiting the Sun

Astronomers have discovered a very distant object in a solar orbit ranging from 6 billion to 213 billion miles from the Sun.

Designated 2015 TG387 and nicknamed “The Goblin” by its discoverers, this object resides in the inner Oort Cloud, a region beyond the Kuiper Belt that until now harbored only two other known bodies: the dwarf planet Sedna and the less well-known 2012 VP113.

The scientists estimate its size to be about 200 miles in diameter. Based on the existence of the three known objects in this region of space, the scientists estimate there could be as many as 2 million objects there bigger than 25 miles in diameter. There is a lot of uncertainty in that number.

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Hayabusa-2’s third mini-lander successfully lands on Ryugu

MASCOT image of Ryugu surface

Update: The image at right, reduced to post here, was taken by MASCOT during its descent. You can see the spacecraft’s shadow in the upper right. If you click on the image you can see the full resolution version.

Original post: The German/French-build mini-lander MASCOT has been successfully deployed by Hayabusa-2 and has successfully landed on the asteroid Ryugu.

MASCOT came to rest on the surface approximately 20 minutes after the separation. Now, the team is analysing the data that MASCOT is sending to Earth to understand the events occurring on the asteroid Ryugu. The lander should now be on the asteroid’s surface, in the correct position thanks to its swing arm, and have started to conduct measurements independently. There are four instruments on board: a DLR camera and radiometer, an infrared spectrometer from the Institut d’Astrophysique Spatiale and a magnetometer from the TU Braunschweig. Once MASCOT has performed all planned measurements, it is expected to hop to another measuring location. This is the first time that scientists will receive data from different locations on an asteroid.

The spacecraft took 20 pictures during its descent, which were beamed to Hayabusa-2 where they are presently stored.

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Deployment operations for Hayabusa-2’s MASCOT lander have begun

Engineers have begun the deployment sequence for Hayabusa-2’s MASCOT lander, with deployment planned for tomorrow.

Right now Hayabusa-2 is slowly moving closer to Ryugu, with live images appearing about once every half hour. More information about MASCOT can be found here. The lander can also hop like the MINERVA bouncers, but it can only do it once. Its battery life is about sixteen hours, so once it is deployed it will only operate on the surface for a short while.

Both the MINERVA and MASCOT mini-landers are mostly engineering tests for using small cubesat-sized spacecraft as probes. So far the MINERVA bouncers have been an unqualified success. Hopefully MASCOT will be as successfully.

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New images from Hayabusa-2’s mini-bouncers

Three press releases from the Hayabusa-2 science team last night provide new images from the spacecraft’s MINERVA bouncers, presently on the surface of Ryugu, as well as new high resolution images from Hayabusa-2 during its recent close-in maneuvers.

The images from the first story also includes a ten second movie showing a very rocky surface with the sun moving across the sky. The last link shows the primary landing site candidate with two backup sites.

All told, these images suggest that Ryugu is nothing more than a rubble pile stuck together. If it was heading to Earth, it might be difficult to deflect it, as it might break apart caused by any stress.

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Minerva probes send back first pictures

Ryugu's surface

Super cool images! The two Minerva probes released two days ago from Hayabusa-2 have both sent back spectacular images from the surface of Ryugu.

The image on the right was captured by the rover dubbed 1A. I have rotated it to show the surface on the bottom, but the actual picture was taking during one of the rover’s bounces while it was moving, so the returned picture had the surface on left. The white brightness is from sunlight. From the press release:

We have confirmed both rovers landed on the surface of asteroid Ryugu. The two rovers are in good condition and are transmitting images and data. Analysis of this information confirmed that at least one of the rovers is moving on the asteroid surface.

MINERVA-II1 is the world’s first rover (mobile exploration robot) to land on the surface of an asteroid. This is also the first time for autonomous movement and picture capture on an asteroid surface. MINERVA-II1 is therefore “the world’s first man-made object to explore movement on an asteroid surface”. We are also delighted that the two rovers both achieved this operation at the same time.

Other released images were taken just after release. One shows a blurred picture of Hayabusa-2, while the other sees Ryugu’s surface below.

Both of these rovers are designed to travel on the surface by a series of hops, taking advantage of Ryugu’s tiny gravity. There will be more images I’m sure from them in the coming days.

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Creeping into Ryugu

Ryugu

Cool images! As Hayabusu-2 creeps to its closest approach to Ryugu in preparation to releasing its first two mini-landers, dubbed MINERVA-II-1 and 2, the images coming down about once every half hour show the asteroid increasingly closer, with the spectacular shadow of Hayabusa-2 with its solar panels clearly visible.

The image on the right was downloaded about 10 pm (Pacific) tonight. The boulder-strewn field of Ryugu is also clearly visible. The black areas are where data has not yet been downloaded. The bright area under the shadow is merely an optical illusion.

UPDATE: A look at this webpage provides some details. When this image was taken the spacecraft was about 60 100 meters above the surface, its closest approach yet. This was also when the MINERVA-II landers were to be deployed.

All later images at the first link above were from a greater distance.

UPDATE: I have corrected the post. They released both MINERVA-II rovers, and they did it about 100 meters distance from the asteroid, not 60. We will not know the mini-landers’ status until late today.

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Hayabusa-2 sees its shadow

Ryugu, with Hayabusa-2's shadow

During its aborted landing rehearsal last week Hayabusa-2 imaged its own shadow as it approached within 600 meters of Ryugu.

The shadow is only a little dot on the surface of the asteroid, but to have resolved it is quite impressive. The image on the right has been annotated by me to indicate the shadow.

They have not said when they will do another landing rehearsal. Meanwhile, two of the spacecraft’s mini-landers are expected to be released sometime in the next few days.

Update: Based on the raw navigation images being released in real time from Hayabusa-2, the release of the MINERVA-II-1 has begun, with Hayabusa-2 moving in towards Ryugu in preparation for that release.

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Cryo-volcanism had less influence on shaping Ceres than predicted

The uncertainty of science: A careful analysis of the Dawn data has found that though cryo-volcanism has occurred repeatedly on Ceres, it had less influence on the dwarf planet’s surface than previous models had predicted.

At the same time, the data also suggests that Ceres has been more active throughout its history than predicted. They found about 22 domes that are apparently past cryo-volcanoes that have flattened out.

“Given how small Ceres is, and how quickly it cooled off after its formation, it would be exciting to identify only one or two possible cryovolcanoes on the surface. To identify a large population of features that may be cryovolcanoes would suggest a long history of volcanism extending up to nearly the present day, which is tremendously exciting,” said Sizemore. “Ceres is a little world that ought to be ‘dead,’ but these new results suggest it might not be. Seeing so much potential evidence for cryovolcanism on Ceres also lends more weight to discussions of cryovolcanic processes on larger icy moons in the outer solar system, where it’s likely more vigorous.”

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Dress rehearsal of Hayabusa-2’s landing scrapped

The dress rehearsal of Hayabusa-2’s eventual landing on the asteroid Ryugu was cut short yesterday when the spacecraft found it could not get a reliable distance reading of the surface once it descended to 600 meters.

The problem was apparently due to the pitch black surface of the carbon-rich asteroid that made laser distance measurements difficult. JAXA says the Hayabusa 2 is in good condition, and the agency is considering changing landing procedures such as adjusting the configuration of measuring devices.

Despite the suspension, the altitude of 600 meters the explorer has descended to the asteroid is the closest ever recorded. JAXA had planned to bring down the probe to 30 meters and make detailed observations of a landing spot.

Just to clarify, this was a height record for Hayabusa-2 only.

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Astronomers use radio emissions from distant galaxy to observe asteroid

The wonders of science: Astronomers have successfully used the faint radio emissions from very distant galaxy to roughly determine the shape and size of a nearby asteroid.

In an unusual observation, astronomers used the National Science Foundation’s Very Long Baseline Array (VLBA) to study the effects on radio waves coming from a distant radio galaxy when an asteroid in our Solar System passed in front of the galaxy. The observation allowed them to measure the size of the asteroid, gain new information about its shape, and greatly improve the accuracy with which its orbital path can be calculated.

When the asteroid passed in front of the galaxy, radio waves coming from the galaxy were slightly bent around the asteroid’s edge, in a process called diffraction. As these waves interacted with each other, they produced a circular pattern of stronger and weaker waves, similar to the patterns of bright and dark circles produced in terrestrial laboratory experiments with light waves. “By analyzing the patterns of the diffracted radio waves during this event, we were able to learn much about the asteroid, including its size and precise position, and to get some valuable clues about its shape,” said Jorma Harju, of the University of Helsinki in Finland.

The amount of information is not great, and there is an enormous amount of uncertainty in the data. Nonetheless, this is an amazing and fascinating observation.

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