Mercury was once alive with volcanoes

While it seems like a geologically dead planet today, early in its history tiny Mercury may have been a cauldron of volcanic activity, NASA scientists said on Wednesday.

Data from the US space agency's car-sized Messenger probe's latest close encounter with the planet nearest the sun on Oct 6 is helping to settle a debate dating back to the 1970s over the role volcanoes played in Mercury's history.

Messenger sent back images showing extensive and deep lava flows on the surface, including hardened lava more than 2 km deep filling a crater 100 km in diameter.