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The Absolute Weirdness of Miranda

Miranda looks like it’s been Frankensteined together. The small, lumpy moon orbits Uranus and has a surface covered by patches of intersecting ridges, weirdly bumpy terrain and pockmarked plains, and dark, irregular canyons. It’s kind of like a badly crafted moon-quilt, except there’s nothing warm and fuzzy about a barren chunk of icy rock with grooves that make the Grand Canyon look like a paper cut.

Earlier this week, I asked a bunch of scientists to share what they’ve been the most surprised by in the solar system. “The absolute weirdness of Miranda,” was one of the responses from planetary scientist Bill Bottke of the Southwest Research Institute. There are a number of bizarre satellites in the solar system, so Bottke pointing to Miranda meant it was worth a closer look.

Miranda was spotted in 1948 by Gerard Kuiper, but it wasn’t until Voyager 2 swung by the solar system’s most unfortunately named planet in 1986 that we got a good look at its little moon. Miranda is only 500 kilometers across, or about one-seventh the size of our moon.

Basically, Miranda appears as though it’s made out of pieces that don’t quite fit together properly, sort of like poor, lurchy Frankenstein. How the moon came to be like this is still a mystery. One theory suggests that in its first incarnation, Miranda was a less-grotesque, more-normal version of itself — until a giant impact or five came along and blew the moon apart. The pieces eventually reassembled, but not in a way that made much sense. Another hypothesis suggests that meteorite impacts locally melted the moon, and slush rising to the surface formed the giant, ridged patches scientists call “coronae.” Other theories have thrown in a little icy volcanism and internal heating caused by gravitational interactions with Uranus and its other moons. Or, Miranda could have begun to differentiate, with its internal layers separating into something like a core, mantle, and crust — but froze before it finished the job.

17 thoughts on “The Absolute Weirdness of Miranda

  1. Considering all the surprises, variety, and weirdness in the solar system, compared to our expectations (of course), it seems like we’ve been given a bunch of puzzles to play with, and on top of that they all must form one big puzzle that we can have fun learning about and trying to put together!

  2. Weird just means not what they were taught by their expert professors. In past years people jumped in line behind the most forceful personalities, and ever after we’re stuck sorting it out.

  3. The lines on Miranda remind me of the look of a bad solder joint. Solder which has been moved while it was still solidifying. Could that be a clue?

  4. I think this is an example of many fragments comming together to try and assemble itself into a sphere but the amount of gravity is right on the edge of not being strong enough to form a complete sphere shape and hold it. We have seen other moons that are to small to form a ball and some larger asteroids that are almost big enough to do it. So the combo of small size and extreme cold are holding it back.
    Sounds as plausible as any other explanation to me, Anybody else think this is possible?

  5. I would go with a theory of rapid cooling of different parts of the surface. Like how ice can form on a puddle with stress and fracture lines, which have been further distorted by meteor impacts.

  6. it does look like it was surface mined..strip mined..after all we started out some 350.000 years ago…it could have been us…?

  7. Hey Mitch, Robert, please try to remember why your folks left those space barges in such a far out orbit. Are we supposed to re-use them? ;)-[

  8. If you read the photograph of Miranda very minutely, you will find seven patches are there. Those are, may be ice piece of different shape which were floating in the space, came under gravitational force of Miranda and shuttered. Please compare north & south pole of the photograph, it clearly indicates some foreign matter stuck by gravity.

  9. I feel very fortunate that at the age of 84 I am able to witness all these amazing
    things being found. Thank you for sharing them with us,

  10. Miranda may have a mantle and crust due to some sort of internal heating or enough pressure to do so. If their was some sort of heating it could cause convection currents. This could create pressure ridges on a larger scale than what we experience on earth. Internal heating could be due to gravitational forces pulling the planet inwards creating larger pressure and higher temperature. If it was pulling itself inwards it would create pressure ridges even if the inside was frozen.

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