As Pluto is finally added to the University of Arizona s scale model solar system, a new study suggests how the drawf planet s cold heart was originally broken.
How Pluto s Sputnik Planitia formed remains unknown, but researchers have imagined a body about the size of Switzerland crashing into Pluto at a shallow angle.
Pluto s heart-shaped scar may offer clues to the frozen world s history yahoo.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from yahoo.com Daily Mail and Mail on Sunday newspapers.