By KATHIANNE BONIELLO
Posted: 3:44 am
July 6, 2008
The smallest planet in the solar system is growing smaller.
The cooling of Mercury's core has reduced its diameter by about a mile over recorded history, according to the journal Science.
A January flyby brought the Messenger spacecraft within 125 miles of the planet closest to the sun and revealed Mercury's contraction, one-third greater than previously believed.
And evidence of ancient volcanic activity was found.
