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.
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.
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.
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.
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.
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.
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.
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.
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.”
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.
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.
The next few months are going to be very busy and exciting for the planetary science community. Seven different probes will be either flying past or landing on four different solar system objects, with interesting events happening every few weeks:
In addition, another Hayabusa-2 mini-lander will also land on Ryugu, sometime after Hayabusa-2’s landing. Moreover, as OSIRIS-REx and New Horizons approach their targets we shall see daily new and increasingly sharper images of both Bennu and Ultima Thule, prior to their arrival.
I expect from September to January there will be many many very cool images coming from space, on almost a daily basis.
The science team for the Japanese probe Hayabusa-2 have set the dates for the first two landings on the asteroid Ryugu.
On 21 September, it will despatch the first of these piggybacked packages. A 3.3kg container known as Minerva II-1, which is mounted on the spacecraft, will deploy two robots known as Rover 1A and Rover 1B.
The 1kg “rovers” will actually move by hopping under the asteroid’s low gravity. Each one contains a motor-powered internal mass that rotates to generate force, propelling the robot across the surface. The rovers are equipped with wide-angle and stereo cameras to send back pictures from Ryugu.
Then, on 3 October, the mothership will deploy a lander called Mascot, which has been developed by the German Aerospace Center (DLR) in conjunction with the French Space Agency (CNES). Mascot, otherwise known as the Mobile Asteroid Surface Scout, is a 10kg instrument package that will gather a range of scientific data from the surface. It carries a wide-angle camera, a microscope to study the composition of minerals, a radiometer to measure temperature and a magnetometer to measure the magnetic field.
After it reaches the surface, Mascot can move its position only once, by jumping.
An earlier report had said that Hayabusa-2 would itself land late in October, but this report today leaves that landing date unstated.
What could possibly go wrong? A scientist has proposed the use of the Earth’s atmosphere to aerobrake resource-rich asteroids into Earth orbit to make them easily available for mining.
In the new paper, Tan and colleagues propose using aerobraking to slow small asteroids enough that they don’t just shoot straight past Earth, but stay in orbit, where they could be mined for platinum or water. Those resources could then be taken to space stations to supply future missions or operations. Water, they write, could even be split into hydrogen and oxygen for fuel. All it would take is a precisely calculated push from an unmanned spacecraft, they report this month in Acta Astronautica.
And if the maneuver were done far enough from Earth—millions of kilometers, in most cases—it likely wouldn’t take much effort. That’s because a small push from far away would greatly change the angle of an incoming space rock’s path. Tan notes that each case would be different, depending on the trajectory of the target asteroid, and says that modifications might be necessary if the asteroid gets off track.
They propose doing this only with small asteroids, less than 100 feet in diameter.
I am sure my readers can outline the numerous problems with this proposal. From my perspective, the primary one is that it is almost impossible to predict the precise path of these kinds of asteroids. Their rotation and irregular shape combined with radiation pressure from the Sun tends to make their solar orbits somewhat chaotic and difficult to predict at the accuracy needed to safely nudge them into a close fly-by of the Earth.
Using particles gathered by Hayabusa-1 Japanese scientists have determined the age of the asteroid Itokawa.
Japanese scientists, including those from Osaka University, closely examined particles collected from the asteroid Itokawa by the spacecraft Hayabusa, finding that the parent body of Itokawa was formed about 4.6 billion years ago when the solar system was born and that it was destroyed by a collision with another asteroid about 1.5 billion years ago.
These results are only the beginning. As more samples return from more asteroids, scientists will start to add details to the overall history of the formation and evolution of the solar system, adding significant depth to the rough outline they presently have. And these new samples are already on the way, with both Hayabusa-2 and OSIRIS-REx approaching their target asteroids.
OSIRIS-REx has taken its first images of Bennu from a distance of 1.4 million miles.
The images are not much to look at, showing a mere dot moving across a star field. Nonetheless, they show that the spacecraft’s camera is working, and that it is on course for its December 3rd arrival.
At a press conference yesterday the Hayabusa-2 science team laid out their landing schedule for the spacecraft and its three tiny landers.
The first lander will be one of its two tiny MINERVA-II probes, and will take place in September. This will be followed by the German/French MASCOT probe in early October, followed in turn in late October by Hayabusa-2 itself.
The landings of the first two probes will help them pick Hayabusa-2’s landing site, as well as the site for last MINERVA lander.
Mission planners faced tough choices because the body almost uniformly strewn with boulders. “Ryugu is beautiful, but challenging,” said Aurélie Moussi, a collaborator from the French space agency CNES in Toulouse, at a press conference in Sagamihara, Japan, on 23 August.
…To minimize risks for MASCOT, mission planners mapped the topography of Ryugu and the distribution and size of the boulders on its surface. They ran computer simulations to produce a shortlist of ten options, and then picked one spot on the asteroid’s southern hemisphere. The choice reflected a number of criteria, including average temperatures on the ground and the materials that MASCOT will analyse with its four on-board instruments. “The other sites would have been just as good, or just as difficult,” says MASCOT payload manager Stephan Ulamec of the German Aerospace Center in Cologne. “Wherever we look, there is a lot of big boulders.”
It does appear that the boulder-strewn surface is posing a problem for the engineers.
Cool image time! With the Dawn spacecraft now swooping with 22 miles of the surface of Ceres every 27 hours, the science team has assembled a spectacular oblique image of Cerealia Facula, one of the dwarf planet’s bright spots thought to be brine deposits that at some point erupted up from below the surface.
The image on the right, reduced in resolution to show here, shows that mosaic. If you click on the image you can see the full resolution version. From the image webpage:
This mosaic of Cerealia Facula combines images obtained from altitudes as low as 22 miles (35 km) above Ceres’ surface. The mosaic is overlain on a topography model based on images obtained during Dawn’s low altitude mapping orbit (240 miles or 385 km altitude). No vertical exaggeration was applied.
There are a lot of intriguing details in the full resolution image. I have highlighted one feature, indicated by the white box and shown in full resolution below.
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The Dawn science team has released their first artist’s concept of the interior of Ceres, based on data gathered by the spacecraft.
Using information about Ceres’ gravity and topography, scientists found that Ceres is “differentiated,” which means that it has compositionally distinct layers at different depths. The most internal layer, the “mantle” is dominated by hydrated rocks, like clays. The external layer, the 24.85-mile (40-kilometer) thick crust, is a mixture of ice, salts, and hydrated minerals. Between the two is a layer that may contain a little bit of liquid rich in salts, called brine. It extends down at least 62 miles (100 kilometers). The Dawn observations cannot “see” below about 62 miles (100 kilometers) in depth. Hence, it is not possible to tell if Ceres’ deep interior contains more liquid or a core of dense material rich in metal.
The most intriguing part of this concept is the existence of a brine layer below the crust. I suspect it is this layer that they believe is the source of the white salty brine that produces Ceres’ ice volcanoes and bright spots.
The annual Perseid meteor shower upcoming on August 12 is expected to be especially good this year because there will be no moon in the sky.
The Perseid meteors seem to come from a single point, the `radiant’, situated in the constellation Perseus, giving the shower its name. This is however just an effect of perspective, as the meteors move parallel to each other, much like drivers see when driving in heavy rain.
The radiant will be visible from around 10pm and at this time there will be the highest chance of seeing `Earth grazing meteors’. These are meteors that skim the Earth’s atmosphere and so have long, blazing tails.
Observers can expect to see a few tens of meteors per hour, or one every few minutes, once darkness has fallen on 12 August. The number of meteors will peak in the early hours of 13 August, when up to around seventy each hour should be visible.
It is worth it to find a nice dark place and stay up all night at least once in your life to watch this shower. Get a nice camp chair that allows you to lie back, make sure you are dressed comfortably, and sit back and enjoy.
