Unexpected Activity on the Planet Mercury

Mercury is supposed to be a dead rock orbiting the sun. There should not be any activity there, no surface features forming, no outgassing of volatile materials, right? Well...

NASA's Messenger spacecraft mission to Mercury has given scientists the opportunity to learn more about the properties of the solar system's innermost planet. After supposedly billions of years since its formation, the planet should be dead, or geologically inactive. New data from Messenger, however, show that Mercury remains active and is still generating surface features. 

Before the Messenger data acquisition, astronomers observed that the sunny side of Mercury is hot enough to melt lead, and like other rocky objects in the solar system, many craters pockmark the planet's surface. In early 2011, Messenger carefully maneuvered into orbit and took photographs with unprecedented detail. 

Images of the planet's surface revealed unusual, irregularly shaped hollows or depressions with rounded edges that were comprised of material so bright that many showed "high reflectance halos." Researchers hadn't expected to find such highly reflective features, which "appear fresh and lack superposed impact craters, implying that they are relatively young," according to the report published in Science.

 Read the rest of "Mercury's Surface Looks Young" here.