Mar 21, 2012 5:30 PM

Planet Mercury Even Weirder Than We Thought

New data suggests that Mercury has undergone much more dynamic processes than previously believed and that its core is unlike any of the other rocky planets in our solar system.

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surface-heights

New data suggests that Mercury has undergone much more dynamic processes than previously believed and that its core is unlike any of the other rocky planets in our solar system. NASA’s MESSENGER spacecraft, which has been in orbit around the solar system’s smallest and innermost planet for just over a year, has beamed back plenty of surprises for scientists here on Earth. “I thought the surface of Mercury would turn out to be complex and the interior simple,” said planetary scientist Maria Zuber of MIT, who is a member of the MESSENGER team and co-author of two new papers on the planet that appear March 21 in Science. “Instead, our data has been such a surprise that we kept thinking we were interpreting it wrong.” Mercury’s tiny size and heavily cratered surface suggested that the planet cooled into an inert lump soon after its formation 4.5 billion years ago. The two new papers show that the planet had active geologic and tectonic processes occurring until at least the planet’s middle age, around 2 billion years ago. Here, Wired takes a look at some of the weirdest new findings of what is turning out to be a strange little world. Above:

Surface Heights

MESSENGER has measured the height of surface features over much of Mercury. This image shows off altimetry data from ancient volcanic plains in the planet’s northern high latitudes. These smooth plains were created at the earliest stages of the planet’s history and have been subsequently deformed. The large white feature in the lower left is an enormous rise in the plains that was created through active geologic processes. Image: NASA/JHUAPL/CIW-DTM/GSFC/MIT/Brown University. Rendering by James Dickson and Jim Head