Mercury’s surface once exploded in volcanoes

Two volcanic vents (center) on the floor of Mercury’s Kipling crater are shown in this false-color MESSENGER image. Volcanic ash appears in brown. 

Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/Brown University/ NASA

Guest post by Christopher Crockett

Volcanoes erupted on Mercury for billions of years, according to new images from the MESSENGER spacecraft.  The pictures, published March 28 in Journal of Geophysical Research: Planets, show ancient vents and ash scattered within craters between 1 billion and 3.5 billion years old, suggesting that the volcanoes exploded over a long period of time.

Sustained volcanism indicates that Mercury kept volatiles — compounds with low boiling points like water — for longer than previously thought. A rich supply of volatiles suggests that Mercury escaped the cataclysmic collisions or erosion caused by the sun that researchers use to explain the planet’s oversized iron core.