Ceres’s big mountain

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Ahuna Mons on Ceres

The Dawn science team has released an oblique angle image of Ceres’s big mountain, Ahuna Mons. I have cropped and reduced it above to show it here.

Despite looking almost toylike in this image, the mountain is quite monstrous, especially considering Ceres’s relatively small size.

This mountain is about 3 miles (5 kilometers) high on its steepest side. Its average overall height is 2.5 miles (4 kilometers). These figures are slightly lower than what scientists estimated from Dawn’s higher orbits because researchers now have a better sense of Ceres’ topography.

Consider: Mount Everest is not quite six miles high, on a planet with a diameter about 7926 miles across. Ceres however is only about 600 miles across at its widest, which means a 3 mile high mountain is 0.5% of Ceres’s entire width! Such a thing could only occur on such a small body, whose gravity is not quite great enough to force things into a completely spherical shape. It is for this reason it could be argued that Ceres doesn’t qualify as a dwarf planet, but would be better labeled a giant asteroid.



  • mpthompson

    Ceres, is not an asteroid??? When did that happen. When I was a kid all the astronomy books said Vesta and Ceres were the two largest asteroids. Were they lying? Next thing you’ll be telling me that Pluto isn’t a planet…

    Strange how this new naming system doesn’t clarify anything which leads me to suspect is was done more to gratify big egos who just wanted to shake things up because they could.

  • Edward

    It happened when Pluto was demoted. According to Wikipedia (that bastion of reliability), its categorization has quite a history:

    It all seems very confusing. Perhaps the IAU has not done us (m)any favors, so far this millennium.

  • Wayne


    HAR! You make me smile & that’s not always easy for me– enjoy your brand of humor!!

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