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Unmanned Spaceflight.com > Other Missions > Cometary and Asteroid Missions > Hayabusa2
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djellison
Was able to extract some 3D data from the three images from Hayabusa during MASCOT's decent

https://sketchfab.com/models/c7155bfcac774d...b4688709b9faca3
elakdawalla
Anybody know the proper credit on MASCOT images?
Explorer1
QUOTE (elakdawalla @ Oct 5 2018, 11:30 AM) *
Anybody know the proper credit on MASCOT images?


According to here (scroll to MASCOT instruments): https://www.dlr.de/dlr/en/desktopdefault.as...#/gallery/31165

"Institute of Planetary Research, DLR"

elakdawalla
Thanks for the link, that's useful. I'm gonna go ahead and add JAXA and CNES in as well...
Blue Sky
Still no information on scale, so it is hard to know what we are looking at. What I am interested in is the first picture, showing the DLR control room. A woman is in the left foreground looking at the projected information on the wall. In the left part of that information is an image of some rocky terrain that does not seem to be among the other pictures they have released.
Baywa
QUOTE (elakdawalla @ Oct 5 2018, 06:30 PM) *
Anybody know the proper credit on MASCOT images?


On the latest images from MASCOT it says Credit: MASCOT/DLR/JAXA

see https://www.dlr.de/dlr/en/desktopdefault.as...#/gallery/32249

Click on "Information"
wildespace
An attempted red-green stereo image using the frames from MASCOT descent:

Click to view attachment

Creadit: JAXA/University of Tokyo/Kochi University/Rikkyo University/Nagoya University/Chiba Institute of Technology/Meiji University/University of Aizu/AIST/Kakitsev ninja.gif
neo56
Hayabusa2 and MASCOT pictures of the same scene from a different point of view:

Click to view attachment Click to view attachment
Hungry4info
There's a much higher quality image of the "hopping location #2" pic from MASCOT on the DLR website. It's embedded into a margin smaller than the image, which shrinks it a bit, but if you open the image itself, you can see a lot more detail.
Roby72
I see on the MASCOT pictures that one side is not focused..somewhat blurry ...is there any reason for this ?

My guess is, that it is not dejustet but if you land upright you have the nearer objects better in focus than the more far away and you not need a focusable lens assembly which adds some risk to the lander.
Or is it really out of focus ?

Rob
Steve G
I was wondering about the same thing. Either the image sensor isn't aligned to the lens due to temperature shift or related stress, or, it's deliberately like that so when the spacecraft is on the surface, and righted, both the foreground and background will be in focus like a tilt shift camera where you change the angle of the negative to increase depth of field.
neo56
I aligned each 3 frames of the MASCOT animation in relation to Ryugu surface:

Click to view attachment
Explorer1
No new pictures, but some science results in this article: https://spaceflightnow.com/2018/10/05/masco...s-expectations/

QUOTE
What we’ve learned so far from the pictures is it looks like the surface is more consolidated rocks overlaid by a thin layer of particulate material,” Grott said.
Stefan
QUOTE (Steve G @ Oct 6 2018, 02:15 AM) *
I was wondering about the same thing. Either the image sensor isn't aligned to the lens due to temperature shift or related stress, or, it's deliberately like that so when the spacecraft is on the surface, and righted, both the foreground and background will be in focus like a tilt shift camera where you change the angle of the negative to increase depth of field.

It is deliberately like that. It's called the Scheimpflug principle.

There's a press conference tomorrow with some new material.
yoichi
https://www.dlr.de/dlr/presse/en/desktopdef...#/gallery/32338
Numerous boulders, many rocks, no dust: MASCOT's zigzag course across the asteroid Ryugu
Explorer1
Finally surface images! Nice oblique view of the giant south pole boulder too! The top seems to be the only big smooth part of Ryugu....

And we have a name for the landing site: 'Alice's Wonderland'
stevesliva
QUOTE (yoichi @ Oct 12 2018, 08:15 AM) *
https://www.dlr.de/dlr/presse/en/desktopdef...#/gallery/32338
Numerous boulders, many rocks, no dust: MASCOT's zigzag course across the asteroid Ryugu


For those like me wondering about the "no dust" in the title, it's described only as "fine material" in the accompanying text.

No dust? Makes you wonder if the dust gets cemented.
Phil Stooke
It's easy to make dust through micrometeorite impacts, and some at least should be retained. But cementing or consolidating it is much more difficult. More likely it's a sifting effect, where jostling by impacts causes large chunks to rise and small objects to fall into spaces between them. On Itokawa the same thing was seen except that in some low-lying areas the fine materal became concentrated in smooth patches. We don't see that here, maybe because Ryugu is more equidimensional.
Hungry4info
This abstract at the 50th LPSC has a new image from MASCOT, taken during local night with the red LED on. The red ellipse is labelled as the radiometer field of view. Is it possible to remove it from the image to try to restore the background image?
https://www.hou.usra.edu/meetings/lpsc2019/pdf/1267.pdf
elakdawalla
Needs a little cosmetic work around the edges of the ellipse, but here's a quick and dirty version:
MahFL
QUOTE (elakdawalla @ Jan 31 2019, 02:13 AM) *
Needs a little cosmetic work around the edges of the ellipse, but here's a quick and dirty version:


Anyone know what the scale is we are looking at ?
Baywa
QUOTE (MahFL @ Jan 31 2019, 04:54 AM) *
Anyone know what the scale is we are looking at ?
In the article it says " MARA observed a rock formation of approximately 60 cm diameter, which is shown in Fig. 1." Fig.1. being the attached picture. But I'm not quite sure: 60cm may also refer to the red ellipse.
Gladstoner
QUOTE (elakdawalla @ Jan 30 2019, 07:13 PM) *
Needs a little cosmetic work around the edges of the ellipse, but here's a quick and dirty version:


Cleaned up, with a bit of necessary artistic license:

Click to view attachment
centsworth_II
QUOTE (MahFL @ Jan 30 2019, 11:54 PM) *
Anyone know what the scale is we are looking at ?
Click to view attachment

If my math is right and the pixels on the image are accurate to the original, I get the 10 cm bar (in black) based on 500 pixels at 0.2mm per pixel at the bottom of the image as mentioned in the image caption.

I get the 60cm bar (in yellow) based on 300 pixels at 2mm per pixel (rough estimation, based on 0.2mm per pixel at the bottom of the image and 3mm per pixel near the horizon as mentioned in the image caption).

Disclaimer: I am not an accomplished image interpreter.
Hungry4info
"MASCOT confirms what scientists have long suspected
Small fragments of carbon-rich asteroids are too fragile to survive entry into Earth’s atmosphere"

Press release:
https://www.dlr.de/dlr/presse/en/desktopdef...x9fOby8qyxi5AWo

Original paper:
Low thermal conductivity boulder with high porosity identified on C-type asteroid (162173) Ryugu
https://www.nature.com/articles/s41550-019-...rPquGwVWtmiCPak
Hungry4info
There are some images from MASCOT at the following website, showing the area that we have seen before, but at four different times of day.
https://mascot.cnes.fr/fr/les-premieres-pho...yugu-par-mascot

At first I was having a hard time connecting surface features but then I realised that MASCOT moved a bit between the late morning and noon images. This is confirmed in the Science paper posted yesterday (23 August 2019).
QUOTE
On the morning of the third day, the lander slipped ~5 cm sideways by executing a mini-move to enable stereo imaging for photogrammetric analysis, reaching a third location (MP3)


I've constructed a 3D anaglyph and a black-and-forth .gif that shows the move, and the 3D perspective of the surface. The 3D image is kinda crude, admittedly.
(Edit: Added a cropped .gif that shows less, of course, but should help look less like a light-switch as that seems to mess with one's mind after a bit)
Hungry4info
Similar in theme to my last post. This animation blinks between the Noon image and the Late Afternoon image, showing differences in illumination angle. It looks like the lander has slid a bit between these two images as well, and I'm pretty confident it is not an artifact of the changes in lighting angle.
Marcin600
Beautiful photos!
This article is also interesting (22 August 2019) with a handful of photos from MASCOT, including this famous picture, which we all waited for. I took out a few of them (Credit: MASCOT / DLR / JAXA).

PS. In the article, informative descriptions are visible under the photos in the Fullscreen option
Marcin600
QUOTE (Hungry4info @ Aug 25 2019, 06:10 AM) *
Similar in theme to my last post. This animation blinks between the Noon image and the Late Afternoon image, showing differences in illumination angle. It looks like the lander has slid a bit between these two images as well, and I'm pretty confident it is not an artifact of the changes in lighting angle.


I think that in microgravity on Ryugu, every smallest movement of scientific instruments inside the lander generates small corps shifts


(„... at 10 kilograms, MASCOT experienced a gravitational force of 0.17 grams on Ryugu...”)
Marcin600
In the cited article there is also an interesting reference to the discussion about dust (or rather its lack) on the surface of Ryugu, which I initiated on this forum a few months ago:

"...Ralf Jaumann and his team were particularly surprised by the lack of dust: "Ryugu's entire surface is littered with boulders, but we have not discovered dust anywhere. It should be present, due to the bombardment of the asteroid by micrometeorites over billions of years, and their weathering effect. However, as the asteroid has very low gravity – only one-sixtieth of that experienced on Earth’s surface – the dust has either disappeared into cavities on the asteroid or has escaped into space. This gives an indication of the complex geophysical processes occurring on the surface of this small asteroid...”
Marcin600
And another quote from the same article is particularly interesting for metorite collectors:

"...Until now, the MASCOT scientists believed that Ryugu was similar to two meteorites that fell to Earth in 1969 in Allende, Mexico, and Murchison, Australia. However, those meteorites barely contain bright particles, probably due to the weathering effect of water in the crystal grid of these minerals. The bright inclusions that have now been observed have led the scientists to conclude that Ryugu's cauliflower-like rocks bear greater similarities to meteorites from Tagish Lake. On 18 January 2000, hundreds of small meteorites rained down on Earth following the explosion of a large fireball over Canada, and numerous fragments were found on the ice of the frozen lake.

These are very rare stony meteorites from what is referred to as the CI chondrite class. The C stands for the chemical element carbon, and the I for the similarity with the Ivuna meteorite found in Tanzania. They are among the oldest and most primitive components of the Solar System, remnants of the first solid bodies to be formed in the primordial solar nebula..."
Marcin600
I added the scale bar according to the original description under the color picture
Marcin600
A little play with a changing perspective in this crazy but beautiful world
Marcin600
QUOTE (Marcin600 @ Aug 27 2019, 02:46 AM) *
I added the scale bar according to the original description under the color picture




I'm afraid, however, that my scale bar is incorrect!!!

Does anyone know how to calculate it correctly?
Marcin600
I just found the right reference

Now the scale is OK rolleyes.gif

Sorry about that!
Marcin600
And yet only a larger version (b/w) of the night picture of the surface of Ryugu (from here )
Marcin600
I am not sure if the color night picture of the Ryugu's surface appeared here in such resolution ( from here ):
(I'm sorry if I repeat myself, but such pictures do not stop to fascinate me - from an anonymous dot of light to the New World)

Credit: MASCOT/DLR/JAXA
Paolo
the latest issue of Astronomy & Astrophysics has three papers (in free access!) on MASCOT:

The descent and bouncing path of the Hayabusa2 lander MASCOT at asteroid (162173) Ryugu
QUOTE
Images from the Optical Navigation Camera system (ONC) onboard the Hayabusa2 spacecraft show the MASCOT lander during its descent to the surface of asteroid (162173) Ryugu. We used results from a previous stereo-photogrammetric analysis that provided precise ONC image orientation data (camera position and pointing), ONC orthoimages, and an ONC-based 3D surface model to combine them with the visibilities of MASCOT itself and its shadow on-ground within the ONC images. We integrated additional information from instruments onboard MASCOT (MASMag, MARA, MASCam) and derived MASCOT’s release position and modeled its free-fall descent path and its velocity over 350 s from its release at ∼41 m altitude above ground until its first contact with the surface of Ryugu. After first contact, MASCOT bounced over the surface of Ryugu for 663 s and came to rest at its first settlement point after four intermediate surface contacts. We again used ONC images that show MASCOT and partly its shadow and reconstructed the bouncing path and the respective velocities of MASCOT. The achieved accuracy for the entire descent and bouncing path is ∼0.1 m (1σ).


The MASCOT landing area on asteroid (162173) Ryugu: Stereo-photogrammetric analysis using images of the ONC onboard the Hayabusa2 spacecraft
QUOTE
A high-resolution 3D surface model, map-projected to a digital terrain model (DTM), and precisely ortho-rectified context images (orthoimages) of MASCOT landing site area are important data sets for the scientific analysis of relevant data that have been acquired with MASCOT’s image camera system MASCam and other instruments (e.g., the radiometer MARA and the magnetometer MASMag). We performed a stereo-photogrammetric (SPG) analysis of 1050 images acquired from the Hayabusa2 Optical Navigation Camera system (ONC) during the asteroid characterization phase and the MASCOT release phase in early October 2018 to construct a photogrammetric control point network of asteroid (162173) Ryugu. We validated existing rotational parameters for Ryugu and improved the camera orientation (position and pointing) of the ONC images to decimeter accuracy using SPG bundle block adjustment. We produced a high-resolution DTM of the entire MASCOT landing site area. Finally, based on this DTM, a set of orthoimages from the highest-resolution ONC images around MASCOT’s final rest position complements the results of this analysis.


The Hayabusa2 lander MASCOT on the surface of asteroid (162173) Ryugu – Stereo-photogrammetric analysis of MASCam image data
QUOTE
After its release and a descent and bouncing phase, the Hayabusa2 lander MASCOT came to a final rest and MASCOT’s camera MASCam acquired a set of images of the surface of Ryugu. With MASCam’s instantaneous field of view of about 1 mrad, the images provide pixel scales from 0.2 to 0.5 mm pixel−1 in the foreground and up to 1 cm pixel−1 for surface parts in the background. Using a stereo-photogrammetric analysis of the MASCam images taken from slightly different positions due to commanded and unintentional movements of the MASCOT lander, we were able to determine the orientation for the different measurement positions. Furthermore, we derived a 3D surface model of MASCOT’s vicinity. Although the conditions for 3D stereo processing were poor due to very small stereo angles, the derived 3D model has about 0.5 cm accuracy in the foreground at 20 cm distance and about 1.5 cm at a distance of 40–50 cm.
neo56
When looking at pictures of the surface of Ryugu, I always feel hard to estimate the scale: are these rocks or pebbles? How big are these rocks ? Obviously, scalebar helps but I find more helpful to add objects of everyday life to the pictures or people to give the scale.

Here is the result I obtained with Hayabusa 2 and MASCam pictures, adding Harrison Schmitt or a pencil on them.
For pictures with no scalebar, I computed the scaled "Harrison Schmitt" on the basis of MASCam FOV, altitude at which pictures were taken and horizontal distance to the object.

Click to view attachment













MahFL
QUOTE (neo56 @ Apr 21 2020, 03:26 PM) *
When looking at pictures of the surface of Ryugu, I always feel hard to estimate the scale: are these rocks or pebbles? How big are these rocks ? Obviously, scalebar helps but I find more helpful to add objects of everyday life to the pictures or people to give the scale.


I really like when Earth objects are added to help with the scale.
fredk
Much appreciated, Neo.

In your second pic, it's good to see Schmitt visiting a boulder reminiscent of the split boulder he visited nearly 50 years ago:



(Which, to date me, is one of my very few clear memories of Apollo.)
Marcin600
QUOTE (neo56 @ Apr 21 2020, 05:26 PM) *
...Here is the result I obtained with Hayabusa 2 and MASCam pictures, adding Harrison Schmitt or a pencil on them...



Excellent and very useful!
Such photomontage currently probably best reflects the feeling of being on the surface of this little world (which probably will never happen to any of us wink.gif )
Paolo
open access paper (with some nice images!) on MASCOT results:

Spectrophotometric Analysis of the Ryugu Rock Seen by MASCOT: Searching for a Carbonaceous Chondrite Analog
Hungry4info
Apparently a lot of images are now public. Some animations from landru are in this link showing a number of different things.
https://twitter.com/landru79/status/1705304921682108693
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