The Kooky World of Uranus’ Disfigured Moon
published during a waning crescent moon.
07/28/2016

Kooky World

Credit: NASA/JPL

The Grand Canyon has its grandeur built into its name. Standing at its dusty rim can feel like you’re overlooking an alien landform, or even a screensaver because wrapping your brain around its immensity requires some mental gymnastics. How many people could you fit in there? Or cars, or elephants?

If you were to visit Miranda, Uranus’ innermost moon, you might feel the same sentiment. That’s because Miranda has canyons of its own — except they’re about 12 times deeper than the Grand Canyon.

It was Voyager 2 that first documented just how captivating the Frankenmoon really is. Scientists had known of Miranda’s existence since the 1940s, but this — this kaleidoscopic terrain! — was a shock. The Voyager missions were the first to explore the far reaches of our solar system, like Jupiter and Saturn (Voyager 1) and Neptune and Uranus (Voyager 2).

Kooky World

Credit: NASA/JPL

Uranus, our toppled friend, has five moons, but Miranda’s has the most dramatic topography: Slapped together are valleys, the tallest cliff in the solar system, and gargantuan shady canyons that may be as deep as 12 miles (20 km). In comparison, the Grand Canyon can reach about a mile deep.

Some parts are young; others are ancient. All are frigid.

Miranda also has coronae, or large polygonal-shaped regions, including a famous chevron, all of which suggest it’s had some tectonic furor. Because it’s one-seventh the size of our moon, its ragged evolution is even more intriguing to scientists.

There are a few theories about how Miranda became a chimerical monster. It may have been violently broken and then reformed. One recent study points to Uranus’ gravitational forces, which can squeeze and stretch Miranda, according to a Space.com report — much like our moon affects Earth’s tides. That convection could have heated up its insides, influencing it resurfacing like Mickey Mouse’s haphazard Fantasia sorcery.

But that’s only half the story. Voyager captured just one side of Miranda, meaning it’s not time to pack up the station wagon and bucket hat quite yet, because there’s still some grandeur left to explore.