The Moon Miranda's Mystery: Just What Defaced it?

There is a small icy moon that circles Uranus that many consider one of the most visually striking heavenly bodies in our solar system. That's because the face of this moon is marred by three incredibly unusual surface features. Now researchers believe they have determined just what created them.

The features - polygonal-shaped regions called coronae - are only present on Miranda's southern hemisphere, and each are at least 125 miles across. They are named Inverness, Elsinore, and Arden.

Interestingly, the northern hemisphere of Miranda was never imaged by the Voyager 2 spacecraft - the only spacecraft to have ever passed by the moon - so it remains a mystery if there are more of these mysterious coronae.

Still, what makes these features so fascinating is that they are pretty unique, boasting trapezoidal shapes that look like massive long drag marks. It was extremely unclear to experts what could have caused them... until now.

According to a study published in the Geological Society of America's (GSA) journal Geology, experts from Brown University recently used numerical models to show how Miranda's shifting ice mantle could have formed these defacing features.

The researchers argue that the coronae likely formed while Miranda was young and in an eccentric orbit with Uranus - moving closer and further from the planet. Such erratic movement likely wreaked utter havoc on the moon's tidal heating, periodically stretching and squeezing its icy outer shell.

The models apparently reflect with relative accuracy what we actually see on Miranda's surface, which were then frozen in time as they are now once the moon's orbit became more standard.

According to the GSA, "this style of resurfacing is similar to plate tectonics on Earth, in that convection is a primary driving force for surface deformation."