On Wednesday, a very astonishing piece of information was given by the NASA scientist that the little planet of the solar system, Mercury, was once alive with volcanic activities during its early history; the planet which now is seen as geologically dead. 

This comes after data and images sent back by the U.S. space agency's car-sized MESSENGER probe, which explored the planet on 6th October. The images displayed extensive and deep lava flows on the surface. The images also suggested hardened lava more than a mile deep filling a crater 60 miles in diameter. 

The scientists said, “The unmanned spacecraft also detected a so-called wrinkle ridge, a long geological feature on Mercury's surface about 2,000 feet high apparently caused by long-ago contraction of the planet as it cooled.”

 Maria Zuber, a Massachusetts Institute of Technology scientist, working on the mission further added, “That's about twice as high as similar features seen on the surface of Mars.”

This marked the second encounter out of the planned three, before the MESSENGER finally injects into orbit around Mercury in 2011. On 14th January 2008, it flew past Mercury and would return in September 2009. 

The scientists also informed that the new observations, when combined with the data from January’s fly-by, points out that the planet most closest to the sun was once a home to volcanic activity on a planetary scale. 

 Further, NASA scientist Marilyn Lindstrom added, “This shows that's there's a lot more volcanism than we see on the surface of the moon, which has always been the planetary body we've compared Mercury to.”

Basically, the surface of Mercury is a blend of volcanic plains, craters created by bygone impacts with space rocks and winding cliffs. 
About 30% of Mercury's surface was mapped by MESSENGER, which never ever had earlier been seen from a spacecraft.