Bennu’s equatorial craters

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Bennu's craters
Click for full image.

The OSIRIS-REx science team today released a neat image of Bennu, highlighting the string of impact craters along the rubble-pile asteroid’s equatorial ridge. The image to the right, cropped and reduced to post here, shows that image. From the release:

Bennu’s darkest boulder, Gargoyle Saxum , is visible on the equator, near the left limb. On the asteroid’s southern hemisphere, Bennu’s largest boulder, Benben Saxum , casts a long shadow over the surface. The field of view is 0.4 miles (0.7 km). For reference, the largest crater in the center of the image is 257 ft (78 m) wide, which is almost the size of a football field.

The photo was taken from a distance of six miles on April 28. The craters illustrate well the rubble pile/sandbox nature of this asteroid. They all look like what you’d expect if the impact was able to easily drive itself deep into the a pile of sand and loose rocks. The resulting crater thus has a very indistinct rim and a sloping floor down to a central point.



  • Col Beausabre

    “saxum”, Latin-English Dictionary online. saxum. Any aggregate of minerals that makes up part of the earth’s crust. It may be unconsolidated, such as sand, clay, or mud, or consolidated, such as granite, limestone, or coal.

  • Frederick Baumann

    Thank you, Colonel!

  • Ray Van Dune

    I have not seen an explanation of the equatorial ridge structure observed on several small asteroids. Is there an explanation available?

  • Ray Van Dune: Yes, there are several reasonable theories for that ridge structure, mostly centered on the asteroid’s rotation combined with the rotation of debris circling the asteroid as it consolidates. The equatorial region is where the bulk of material will settle.

    Do a search on BtB for rubble pile, asteroid, Bennu, Ryugu, in a variety of combinations. I am sure I have posted a link to these theories.

  • I R A Darth Aggie

    I’m not saying they’re gun ports. But they’re gun ports.

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