Getting your player ready...
Mercury is not just the solar system’s shrimpy kid brother, at least since Pluto was kicked out of the planetary club two years ago. It’s shrinking.
New measurements taken by NASA’s Messenger spacecraft earlier this year show that the innermost planet has shrunk by more than a mile in diameter over its history. Scientists attribute that to the gradual cooling of the planet’s core.
Messenger is the first spacecraft to study Mercury up close since Mariner 10 in 1975. The first comprehensive results from its January flyby are being published in today’s issue of the journal Science.
