Orbital images of Bennu


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Close-up of Bennu's southern hemisphere

The OSIRIS-REx science team has released two new images of Bennu’s southern hemisphere, taken from orbit. The image on the right is a cropped section of the highest resolution version of a montage of two images. Click on the image to see the entire two-image montage.

These two OpNav images of Bennu’s southern hemisphere, which each have an exposure time of about 1.4 milliseconds, were captured Jan. 17 from a distance of about one mile (1.6 km). They have been cropped and the contrast has been adjusted to better reveal surface features. The large boulder – fully visible in the middle of the left frame and in partial shadow in lower portion of right frame – is about 165 feet (50 meters) across.

The cropped section to the right shows that large boulder in the middle of the frame.

I’m sorry, but when I look at this rubble-pile asteroid I cannot help but think of the cat-litter clumps I remove from our cats’ litter box. The only fundamental difference is that the grains in cat litter are made to be a uniform size, while at Bennu the grains are much coarser and not uniform. Nonetheless, this asteroid is a clump of many grains, just like those cat litter clumps, and will likely crumple easily into a cloud of grains if smacked just hard enough.

This knowledge is actually very critical, as Bennu is a potentially dangerous asteroid with an orbit that might have it impact the Earth in about two hundred years.

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4 comments

  • MDN

    Interesting observation. As such a loose aggregate it would seem likely that a penetrating (bunker buster type) nuclear weapon could effectively mitigate an impact risk.

    It wouldn’t “destroy” the material per se, but it would disperse it into a cloud of much smaller elements. The question to answer would be what happens to that 165 foot size boulder? Would it break apart too, or would it survive intact and be a good proxy for the largest remnants we could expect?

    I suggest this could be worth a “test” experiment, but not on Bennu since it is in a near impact orbit already and we wouldn’t want to do this unless a large impact was really imminent. But given that Ryugu and Bennu both appear quite similar I presume many/most of the asteroids out there are similar, and we could pick one in a much safer orbit to blow up to see what happens. It would generate interesting science and be quite entertaining at the same time.

  • Jerry Greenwood

    It’s the product of the diligent work of a dung beetle. The gif from a few weeks ago failed to show the beetle but it was on the back side pushing it along.

  • Jerry Greenwood

    I’m still thinking this is the final product of a giant galactic dung beetle. https://m.youtube.com/watch?v=51O_gJ0gK6A

  • Jerry Greenwood

    Thanks Bob for correcting the glitch.

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