Asteroid approach, Science operations begin! Options

[Holder of the Tw...]

NASA update on the OSIRIS-REx mission, includes first picture of the asteroid from the spacecraft.

Begins Operations

[B Bernatchez]

First Approach Maneuver completed:

https://www.asteroidmission.org/?latest-new...proach-maneuver

[Explorer1]

New images! (they will be leaving the '8-bit' phase pretty soon)

https://www.asteroidmission.org/bennu-oct-2018-pixel-zoom/

[mcaplinger]

https://www.asteroidmission.org/bennu-oct-2018-pixel-zoom/

When I first read this I assumed that there was an error in the captions: at a little under 10,000 km range Bennu is only 3.7 pixels in Polycam? But it's true, and that just goes to show how dinky Bennu is. Polycam's IFOV is 13.5 urad so at range R Bennu (246 meters mean radius) subtends 0.246*2/(R*13.5e-6) pixels.

[Explorer1]

https://www.asteroidmission.org/bennu-jupit...exobservations/

New image, plus a comparison with the Jupiter observation from last year to illustrate the albedo difference. Seems like another Ryugu so far....

[Hungry4info]

New rotation movie from 3000 km taken on 23 Oct 2018. We can see surface features, even if it's not clear exactly what they are.

https://www.asteroidmission.org/bennu-13px/

[Phil Stooke]

These are the 3 frames in that short movie, a bit processed. One suggests a crater, maybe bigger (relatively) than any on Ryugu.

Phil

[Guest_mcmcmc_*]

Countdowns:
https://programmi.000webhostapp.com/osiris/...is-counter.html

They are based on odd data: "future telemetries" available as "digital readouts", which always says 00:00 is the time of the maneuvers, and PDF schedule, I don't know where to find better data.

[Guest_mcmcmc_*]

Countdowns:

Found more rich but less embellished countdowns:
http://www.whereisroadster.com/osiris_rex/

[Paolo]

Bennu at 100 Pixels

looking a lot like Ryugu

[Phil Stooke]

One very good thing about this is that I can use exactly the same map projection for Bennu as I used for Ryugu. Only the scale has to change.

Phil

[Guest_mcmcmc_*]

These direct query links to NASA Horizons provide objects distance from the Sun in km:

OSIRIS-Rex
Bennu

Look for "$$SOE" in result; distance in km is value 3 counting from 0.
Resulting current distance between OSIRIS-Rex and Bennu:
2018-Oct-31 14:40 - 236.16 km

It looks quite precise despite the big distance: this method gives 7 km as Hayabusa2-Ryugu distance, which is currently 5 km.
I think the distance is based on light travel time.

[mcaplinger]

There are SPICE kernels for Orex at https://naif.jpl.nasa.gov/pub/naif/ORX/kernels/ -- AFAIK this is what the flight team is using.

[Guest_mcmcmc_*]

There are SPICE kernels for Orex at https://naif.jpl.nasa.gov/pub/naif/ORX/kernels/ -- AFAIK this is what the flight team is using.

I have no idea of what SPICE kernels are.

[mcaplinger]

I have no idea of what SPICE kernels are.

They are files that capture the position and orientation of spacecraft and solar system bodies, used for mission planning and data analysis. https://naif.jpl.nasa.gov/naif/aboutspice.html

If NASA Horizons does what you want, then by all means use it. I'm not certain how frequently it's updated, however.

[Guest_mcmcmc_*]

They are files that capture the position and orientation of spacecraft and solar system bodies, used for mission planning and data analysis. https://naif.jpl.nasa.gov/naif/aboutspice.html

If NASA Horizons does what you want, then by all means use it. I'm not certain how frequently it's updated, however.

It's not clear to me how these data about spacecrafts are produced; are they recorded data up to current date and calculated data from now on? i.e. are they daily updated? or just calculated from mission schedules? OSIRIS data clearly show the trajectory correction maneuvers occurred during last months, but Hayabusa data show almost constant distance 7000m from Ryugu for same period, which is not true because Hayabusa actually passed from 20.000 to 20m and the other way round several times.

[djellison]

It's not clear to me how these data about spacecrafts are produced; are they recorded data up to current date and calculated data from now on? i.e. are they daily updated? or just calculated from mission schedules?

Yes. All of the above. Sometimes they are reconstructed. Sometimes they are predicted. Sometimes updated very regularly. Sometimes not. Metadata is usually included to explain the source of the data used.

[Phil Stooke]

An approach GIF was just released - these are the 4 best frames, rescaled. The surface is becoming clearer.

Phil

[Hungry4info]

Two Sides of Bennu

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[Explorer1]

Interesting dark patches in the southern hemisphere on the right image, and what might be a crater on the far right limb?
EDIT: rotation movie out! I'll leave it to the experts.... https://www.asteroidmission.org/bennu-rotation_20181102/

[charborob]

Bennu full rotation at 200 pixels.

[Phil Stooke]

Beautiful! That should be enough for a preliminary shape model and map.

Phil

[Guest_mcmcmc_*]

Beautiful! That should be enough for a preliminary shape model and map.

Phil

Shape model (just look, don't touch :-( ):
https://twitter.com/3Dmattias/status/1059936642612502529

[walfy]

Here's a quickly rotating GIF in 3D of it, with contrast boost. Will post a slower next.

[walfy]

This version spins much slower, at 3 second intervals, less jarring on the eyes:

[Phil Stooke]

Nice! And another way of presenting the data in the animation, a set of frames. The last one is a repeat of the first one. A bit of a contrast stretch was applied.

Phil

[Roman Tkachenko]

Asteroid Bennu Rotation (3D animation)

[Guest_mcmcmc_*]

Interactive video:
http://win98.altervista.org/space/explorat...r/rotation.html
(allow several seconds until all 250 frames load).


Updated monitoring page:
http://win98.altervista.org/space/exploration

[charborob]

Bennu at 300 pixels.

[Spock1108]

Bennu is really very small compared to Ryugu, it's as big as Itokawa ... but why doesn't Itokwa have the same shape?

[Holder of the Tw...]

I guess the best word I can think of here is "ironic".

Hayabusa 2 was planned with three sample acquisitions in mind, with the idea of getting diverse samples. But Ryugu turned out to appear fairly homogeneous so now they are only planning one sample (what about the sub surface sampling though? But I digress... ).

Then you have OSIRIS-REx only planning one single sample grab from Bennu.

I know they haven't reported anything yet about any of Bennu's compositional differences but, well... just look at it.

Technically, they could make three tries at sampling, provided the canister didn't fill up on the first try, so I wonder if they might rethink things.

Also, I'm a little worried at this point. OSIRIS-REx seems to be counting on there being dust and small pebbles for its sampling. It is still too far from Bennu to tell, but if the surface turns out to be like Ryugu with nothing but larger pebbles and rocks available, I wonder how they will deal with that.

[tanjent]

That's a nice side-by side comparison of the three bodies, and it is consistent with the unexpectedly rocky surface of Ryuku and likely Bennu too.

Isn't that how panning for gold works? If you put heterogeneous gravel in a pan and agitate it, the smaller particles will settle to the bottom and the larger chunks will "float" to the top, even if they are intrinsically denser, because their irregular shapes prevent them from packing together as tightly. So in a rubble pile asteroid, the finer material will tend to migrate to the center. Itokawa probably had a bit more structural rigidity than the other two, at least enough to prevent this sorting process from proceeding quite so far.

The similar slightly oblate shapes of Ryugu and Bennu seem to reflect a balance between centrifugal force and their minimal gravity which may prove to be the norm for very loosely accreted piles of variously-sized junk.
If so, it may well complicate the sample collection process as Holder suggests.

[Adam Hurcewicz]

OSIRIS-REx Arrival to Bennu (3-18 Dec 2018)


https://www.youtube.com/watch?v=Yrc4jR3Gy5M


I use SPICE (bsp,bc,tsc,tpc,tf) files from NAIF/NASA
Model of OREX is from NASA 3D models converted to cmod.

Soft is Celestia 1.7 64bit

More info apout arrival :
https://www.asteroidmission.org/asteroid-operations/

[Daniele_bianchin...]

I allowed myself to revisit Emily's comparison (Itokawa + Ryugu) and add asteroid Bennu:

[PhilipTerryGraha...]

This is what I'm assuming to be new, higher-resolution MapCam imagery. This GIF is featured on the mission's front page and the "spacecraft imagery" page, but clicking on the link (https://www.asteroidmission.org/?attachment_id=12095#main) leads to a 404... Anyways, many congratulations to the OSIRIS-REx team for completing the long journey to Bennu! I wish nothing but the very best for the mission ahead!

[Holder of the Tw...]

At the OSIRIS-REx website, the caption for the above image sequence reads as follows:

This series of images taken by the OSIRIS-REx spacecraft shows Bennu in one full rotation from a distance of around 50 miles (80 km). The spacecraft’s PolyCam camera obtained the thirty-six 2.2-millisecond frames over a period of four hours and 18 minutes.

Date Taken: Nov. 25, 2018

Instrument Used: OCAMS (PolyCam)

Credits: NASA's Goddard Space Flight Center/University of Arizona

Congratulations to the spacecraft team for a successful arrival today!

[vjkane]

I suspect it may take a lot of careful planning to find a safe touchdown surface on that asteroid.

[ElkGroveDan]

The first thing that stands out is how unusually sharp and angular the surface debris appears.

[Y Bar Ranch]

The animation makes it look like boulders should be flying off of it left and right.

It'd be interesting to run a "Project Crowbar" to lever off one of the bigger boulders and drag/toss it into orbit for a full grapple and analysis.

[elakdawalla]

I pride myself on being able to discern solar system worlds, but if it were not for Ryugu's special polar boulder and Bennu's "pimple" boulder I would not be able to tell the two apart without consulting reference images.

[Hungry4info]

One thing that will help will be that the camera views aren't going to be constantly at full phase.

Here's Bennu at half phase from MapCam.
https://www.asteroidmission.org/20181203_mapcam/

[nprev]

Sure is a jagged little beast. Makes me wonder if the regolith is relatively fresh with less thermal & micrometeoritic weathering than we've seen on other comparable bodies.

[HSchirmer]

...
Isn't that how panning for gold works? If you put heterogeneous gravel in a pan and agitate it, the smaller particles will settle to the bottom and the larger chunks will "float" to the top, even if they are intrinsically denser, because their irregular shapes prevent them from packing together as tightly.

Actually, what you're describing is "the Brasil Nut Effect" and there's even a paper on this
"The spherical Brazil Nut Effect and its significance to asteroids" https://academic.oup.com/mnras/article-pdf/...556/stu1388.pdf

Panning for gold is kinda the opposite, based on bulk density rather than grain size. Since gold is denser than stone, it is retained in the pan, or settles out into the grooves of a sluice, or if you're really old-school, settles out in the wool of a sheepskin...

[Holder of the Tw...]

High Phase Angle Picture taken seven hours before arrival by MapCam (click on link).

There will be a press conference December 10th to discuss the initial scientific results from approach, along with presentations at the AGU (American Geophysical Union) meeting on the 11th and 12th.

Press Conference Page

Get ready for some asteroid science. Now that OSIRIS-REx has arrived at Bennu, the mission team will be presenting the initial results of their scientific studies of the asteroid during the spacecraft’s Approach Phase. The highlights will be discussed at a press conference on Dec. 10 at the American Geophysical Union’s fall meeting in Washington, DC. For conference attendees, three special scientific sessions in collaboration with JAXA’s Hayabusa2 mission will explore the early results from both missions in more detail on Dec. 11 and 12

[Guest_Steve5304_*]

High Phase Angle Picture taken seven hours before arrival by MapCam (click on link).

The thing on the bottom left looks like a flat curled up sheet

Its probably an optical illusion but man this thing has definitely collected a lot of rocky stuff over the years. Much different than Ryugu


Full Rotation

https://www.asteroidmission.org/?attachment_id=12182#main

[Holder of the Tw...]

News conference ready to start in fifteen minutes. (2pm EST December 10th)

LINK

[pbanholzer]

News conference ready to start in fifteen minutes. (2pm EST December 10th)

LINK

The AGU link has expired but it is available on Youtube https://www.youtube.com/watch?v=WRCzK8uZvoY

[elakdawalla]

Here are a few images from the press briefing materials shared yesterday, including a color MapCam portrait. If you break the MapCam view down into its channels, you can see that they didn't reproject the images before combining them into an RGB product -- there's evident rotation of the asteroid between red, green, and blue channels. They're also massively stretched. Can any of you image processing sorcerers do a better job with the image processing and maybe create a nice color portrait of Bennu?

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[elakdawalla]

This is the best I can do -- please someone here do better than me so I don't have to post this garbage on my website

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[Ian R]

Here's a mediocre effort of my own, Emily

[charborob]

Bennu North Pole flyover.

[kenny]

OSIRIS-REx has successfully entered orbit around Bennu.
It is orbiting a mere 1 mile (1.75km) from the centre of the asteroid !

More details here...

NASA announcement

Happy New Year to all, and looking forward to an extraordinary few days in solar system exploration...

[MarkG]

[quote ...It is orbiting a mere 1 mile (1.75km) from the centre of the asteroid !
[/quote]

I believe the orbital period is 62 hours, which makes the orbital velocity about 3 meters/minute, 50mm/sec. (10ʻ/min, 2"sec).

[Marcin600]

New image - Bennu’s south pole: https://www.asteroidmission.org/mapcam-sout...0181217t061345/

I see a nice little crater with a flat bottom and a typical (?) grouping of large boulders in the pole region

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[Explorer1]

Very nice high-res view near the north pole: https://www.asteroidmission.org/mapcam-north-pole-20190220/

[Marcin600]

New pics - region of Bennu’s northern hemisphere close up: https://www.asteroidmission.org/2019-02-25-...-compilation-3/
with: "pond” of regolith that is mostly devoid of large rocks" and "15 meter boulder"

[Hungry4info]

Bennu has plumes! (or perhaps rather ejections of material)

Shortly after the discovery of the particle plumes on Jan. 6, the mission science team increased the frequency of observations, and subsequently detected additional particle plumes during the following two months. Although many of the particles were ejected clear of Bennu, the team tracked some particles that orbited Bennu as satellites before returning to the asteroid’s surface.

The OSIRIS-REx team initially spotted the particle plumes in images while the spacecraft was orbiting Bennu at a distance of about one mile (1.61 kilometers). Following a safety assessment, the mission team concluded the particles did not pose a risk to the spacecraft. The team continues to analyze the particle plumes and their possible causes.

https://solarsystem.nasa.gov/news/877/nasa-...-big-surprises/



More images:
https://svs.gsfc.nasa.gov/13154

[Explorer1]

So Bennu apparently has temporary moons every once in a while. I wonder if the spacecraft could get close to one of the larger ones to resolve it. Hopefully the team is confident these events won't be too big a deal and they can narrow the site they occur (I wouldn't want one nearby during sample collection!).

[PhilipTerryGraha...]

So we've uncovered a contact binary KBO that's really flat, and a Near-Earth asteroid that's spewing rocks into its orbit. What other weeeird stuff is 2019 gonna give to us, I wonder? On topic though, has the OSIRIS-REx team been able to locate where the sources of these ejections are on Bennu? I anticipate that'll be a new priority.

[nprev]

Hard to think of anything that would cause this aside from straight-up thermal expansion. Pockets of volatiles sublimating would presumably produce far more energetic (and dense, and visible) plumes.

Maybe it does something similar at aphelion when contraction happens, or maybe that's just how the mechanical energy gets 'loaded' for perihelion passage burps like these. Still...without any significant surface gravitation that's not gonna cause much compression of surface materials at all.

Regardless: Cool. That's why we're here.

[stevesliva]

You mention thermal and mechanical/gravity. There's also electrostatic...

[Gerald]

Agreed, electrostatic charging due to solar UV may do it, as well. Even a weak repulsive force would be sufficient. I think, that 10V are considered reasonable in direct sunlight. Impacts of micrometeorites might be another approach. Tracking particles, and their acceleration due to solar radiation pressure and some potential weak electrostatic field could clarify the physics at work. Those fields would change with solar irradiation.

[Marcin600]

Or maybe Bennu is a body reassembled from fragments scattered after a relatively recent breakdown by impact and it is still undergoing a rearrangement of its surface (creation of the equatorial ridge) under the influence of its own gravity. Such small surface movements could throw small particles into space (?)

[bsharp]

Image processing artifacts or a lot more particles orbiting around Bennu?

Cranked up brightness levels in original image https://www.asteroidmission.org/?attachment_id=15595

[fredk]

Recall that that press release image was a composite of two frames, differing by a factor of a few thousand in shutter speed. So if you're referring to the arc of bright pixels reaching clockwise around Bennu from the main "jet", the sharpness of that arc's inner edge suggests that edge is the splice between the two frames. Since the outer exposure was much longer, it was probably picking up some glare from the main asteroid's body, which appeared as a sprinkling of bright pixels.

The main "jet" would appear much, much fainter (or be invisible) if this was a single exposure.

[bsharp]

Since the outer exposure was much longer, it was probably picking up some glare from the main asteroid's body, which appeared as a sprinkling of bright pixels.

Thx, yes, I guessed just as much. The other composite (posted here yesterday) shows the glare and the thorough identification process by the team, this wouldn't have escaped them. "Jet" particle sizes were said to be cm size, even as much as 30cm.

[tolis]

if memory serves, the charge-to-mass ratio of cm-sized particles would be far too low for electrostatic forces to play a role. This is some combination of day-to night thermal cycling + rotational state + composition.

[Roman Tkachenko]

This 3D visualization is based on my preliminary 3D shape model and data taken by NASA's OSIRIS-REx spacecraft.

https://youtu.be/QRWdBoQm7J0

[Phil Stooke]

Very nice!.

Here is a map of Bennu. The main part of the surface is derived from a map on the mission website which extends from 70 N to 70 S. I had to fudge the poles (as we cartographers say) from other images. A couple of rocks have informal names (The Gargoyle is one of them), which I will add when I figure out where they are. If anyone knows of any other informal names let me know.

The map projection is the same as I used for the Ryugu map, as they are so similar in shape.

Phil

[elakdawalla]

Nice map! I believe that the rock at 45S 130E is "Ben-Ben." https://twitter.com/elakdawalla/status/1079919898514485248

[charborob]

Bennu boulder in 3D.

[Marcin600]

New pictures on the OSIRIS-REx website:
Bennu’s Equatorial Ridge - https://www.asteroidmission.org/20190329-fb4-equator-view/,
Global Mosaic with a coordinate grid - https://www.asteroidmission.org/bennu-sides...-global-mosaic/ ,
3D view from Laser Altimeter (OLA) measurements - https://www.asteroidmission.org/bennu-visua...d-by-ola-large/

and collection of 7 Nature papers (free and with many interesting pictures and conclusions) - https://www.asteroidmission.org/?latest-new...llection-nature

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[Marcin600]

Two Bennu's pictures ( https://www.asteroidmission.org/20190329-fb4-equator-view/ and https://www.asteroidmission.org/?attachment_id=15551#main), turned, cropped and brightened (as Bennu is very dark) - give a bit of sense of view from above the surface

I added a scale

For future astronauts, the terrain would be difficult to move around (large boulders everywhere), and microgravity would probably not help walking (constant danger of "flying away" into space)

I think it would be a bit like trying to walk on the bottom of the sea with an oxygen bottle on your back. This would require lengthy practice. And no one, even a large rock, gives support, because it can "fly away" with you. Anyway, big boulders, carelessly pushed too much and fluttering around your head is quite scary vision.

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[Marcin600]

Interesting photos from OSIRIS-REx:
really huge boulder in the northern hemisphere - https://www.asteroidmission.org/20190307-po...rthern-boulder/
cracked boulders on the equator - https://www.asteroidmission.org/20190307-po...m-cracked-rock/
I changed the first one slightly

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[Marcin600]

More beautiful boulders: https://www.asteroidmission.org/20190307-so...boulder-region/
(I love big boulders in small worlds )
Many meteor collectors (including me) would like to have such "pebble" - it is CM chondrite, like Murchison (or something very similar)

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[Daniele_bianchin...]

This revolutionizes a bit how I imagined the surface of asteroids forever and how we all imagined it, I think. It does not seem something anomalous or alien but something very common, any valley of terrestrial stones that is often found in the high mountains. I am trying to imagine the men in scale in these photos, exploring among those numerous rocks and I realize that there are so many that it would be difficult to walk there. So many "common" rocks let me think of the remains a part of an already existing and exploded world rather than an agglomeration formed with millions and millions of years. I probably can't conceive.
[]

[Marcin600]

"Benben" - largest boulder on Bennu: https://www.asteroidmission.org/20190307-polycam-benben/

(I found in reliable Wikipedia: "Benben was the mound that arose from the primordial waters Nu upon which the creator deity Atum settled in the creation myth of the Heliopolitan form of ancient Egyptian religion. The Benben stone (also known as a pyramidion) is the top stone of the pyramid. It is also related to the Obelisk." - https://en.wikipedia.org/wiki/Benben

And for fun, and for scale - a brave future astronaut exploring this huge rock with pickax

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[Marcin600]

This revolutionizes a bit how I imagined the surface of asteroids forever and how we all imagined it, I think. It does not seem something anomalous or alien but something very common, any valley of terrestrial stones that is often found in the high mountains. I am trying to imagine the men in scale in these photos, exploring among those numerous rocks and I realize that there are so many that it would be difficult to walk there. So many "common" rocks let me think of the remains a part of an already existing and exploded world rather than an agglomeration formed with millions and millions of years. I probably can't conceive.
[]

"So many "common" rocks let me think of the remains a part of an already existing and exploded world rather than an agglomeration formed with millions and millions of years."

In the case of Ryugu, according to this article in Science, one of the models of its origin assumes that it (or rather its parent body) was broken into pieces by catastrophic impact and reaccumulated, at least a couple of times! Maybe the same applies to Bennu (?)

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[AndyG]

I need help here.

I can see a protoplanetary disc containing silicon and oxygen, and I can see these elements combining to make molecules that may later join together to form rock-dust-bunnies, bonded by electrostatic forces.

Here on Bennu I'm looking at consolidated rocks, alongside other 'conglomerates' that do not appear, at least at first glance, as particularly rock-like.

What is the step from dust to solid rock? Does it imply gravity (there's precious little here), heat from impacts (but, then, what keeps the dust together in such a collision?)

How does it potentially occur?

Andy

[Marcin600]

I need help here.

I can see a protoplanetary disc containing silicon and oxygen, and I can see these elements combining to make molecules that may later join together to form rock-dust-bunnies, bonded by electrostatic forces.

Here on Bennu I'm looking at consolidated rocks, alongside other 'conglomerates' that do not appear, at least at first glance, as particularly rock-like.

What is the step from dust to solid rock? Does it imply gravity (there's precious little here), heat from impacts (but, then, what keeps the dust together in such a collision?)

How does it potentially occur?

Andy

Remember that small rocky asteroids like Bennu or Ryugu are not substantially primordial bodies, but formed from the breakdown of much, much larger asteroids. On these larger parent bodies (primordial), gravity was much higher, impact resistance was greater and, at the beginning, there was a lot of heat from the decomposition of short-lived elements, like aluminium (aluminum isotope Al26

[Marcin600]

As far as I know, the details of the transition "from dust to rocks" are not well known (?) and it is being investigated (and its vision changes) before our eyes! The only "truly" primordial object we have seen so far is Ultima Thule, but it has a different composition (a lot of "ice"), because it is located (and always was there) far from the Sun.

[alan]

The popular model these days is that in the protoplanetary disk dust grews into pebbles, probably mm sized in the inner solar system. In some parts of the disk these be came concentrated enough by one of a variety of of mechanisms to undergo a gravitational instability which caused clumps of them to collapse into asteroids ~100km in diameter. The consolidated rocks would form in these asteroids and be broken up and scattered in later collisions.

[JRehling]

My understanding, via meteorites:

Parent bodies were either differentiated (large enough to have possessed sufficient radiogenic heat to melt) or not. From those that were smaller, we have chondrites, whose solid minerals date back to the first millions of years after the origin of the solar system. Chondrites have iron in abundance along with other stone – a lot like the overall composition of the Earth or Venus if you count the cores and mantles both – but in the chondrites, iron and stone are mixed on a fine level.

From larger parent bodies, exemplified near the larger end by Vesta, we have achondrites. Like smaller versions of the Earth and Venus, these were large enough to melt through, and their iron descended into a core, leaving a relatively iron-poor mantle/crust. Meteorites from Vesta therefore have elemental composition approximately like the crusts of Earth or Venus.

Bennu sure looks like some interesting geology has taken place, but it is classified as carbonaceous and is thus likely a fragment of a smaller, undifferentiated parent body rather than a larger one. If so, we'll expect to find higher levels of iron when we get those samples.

http://meteorites.wustl.edu/metcomp/index_files/image002.gif

[charborob]

Looking at the published images of Bennu (link), I noticed that two of them could be stitched together:

[Marcin600]

North side of Bennu's largest boulder (nicknamed Benben) - rotaded, brightened and with scale bar. In the third picture for scale is Apollo 12 astronaut Pete Conrad with Surveyor 3

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[Marcin600]

And a bit more "free" version of this photo with Apollo 12 astronaut Pete Conrad with Surveyor 3 for scale

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[climber]

Why did you choose the shortest men on the Moon?

[Marcin600]

Why did you choose the shortest men on the Moon?

Because he was most photogenic

[charborob]

Two of the recently posted images of Bennu could be stitched together:

[Holder of the Tw...]

Four candidate sample sites on Bennu have been selected.

Link to News Release on Candidate Sample Sites for OSIRIS-Rex

[stevesliva]

Granted it's in bold at the bottom of the release, but I almost missed it... this web-media feature has a bunch of imagery and discussion and analysis of all four sites:
https://www.asteroidmission.org/candidate-sample-sites/

[Phil Stooke]

Time to update my map.

Phil

[John Moore]

Nice animation (and explanation) HERE of the four possible sites (definitely do a full screen on this).

John

[Marcin600]

Surprisingly regular pattern of cracks on Bennu's boulder ( from this picture ).

The beauty of natural physical processes common in the Universe...

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[Holder of the Tw...]

The down selection to a primary and backup sampling site could occur as early as today.

In the meantime here are a couple of article links. One is an update and another is about a close call that almost postponed the sampling a great deal.

LINK: The midst of selection

LINK: Engineers pull off rescue !!!

Quote from the end of the second article:

NASA will announce the primary sample site, as well as a backup, on Dec. 12. Two final reconnaissance flyovers at even lower altitudes beginning in January will allow the OSIRIS-REx team to collect final, detailed images of these sites.

[Holder of the Tw...]

It will be Nightingale. Osprey is the backup site.

Spaceflight Now Article: NASA selects sites on Bennu

[Marcin600]

New, detailed pictures of the surface of Nightingale, taken January 22, 2020 from 600 m - on the OSIRIS-REx website (and also nice mosaics).
Pictures: NASA/Goddard/University of Arizona, slightly changed.

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[Marcin600]

More nice boulders from a 600 m (pictures from OSIRIS-REx: NASA/Goddard/University of Arizona, slightly changed)
The first one looks a bit like cracked erratic with glacial polish

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[Marcin600]

From the OSIRIS-Rex website: "On Feb. 11, NASA’s OSIRIS-REx spacecraft safely executed a 0.4-mile (620-m) flyover of the backup sample collection site Osprey... Preliminary telemetry, however, indicates that the OSIRIS-REx Laser Altimeter (OLA) did not operate as expected during the 11-hour event. The OLA instrument was scheduled to provide ranging data to the spacecraft’s PolyCam imager, which would allow the camera to focus while imaging the area around the sample collection site. Consequently, the PolyCam images from the flyover are likely out of focus. The other science instruments... all performed nominally during the flyover... The mission team is currently reviewing the available data from the flyover in order to fully assess the OLA instrument..."

[Marcin600]

First official (approved by IAU) Bennu surface feature names: 11 boulders (Saxum) and 1 Regio.
Most prominent boulder (22 m high) is officially designated Benben Saxum.

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