Researchers have calculated that carbon dioxide snow particles on Mars are roughly the size of a human red blood cell. Martian snow is depicted in this artist's rendering as a mist or fog that ... more 
Researchers have calculated that carbon dioxide snow particles on Mars are roughly the size of a human red blood cell. Martian snow is depicted in this artist's rendering as a mist or fog that eventually settles to the surface. less 
1 / 3
SPACE.com | Photo By NASA, Christine Daniloff/MIT News
Fri, Jun 22, 2012 12:37 PM EDT