Pluto's 'heart' may be cold as ice, but it's in the right place, according to research
http://phys.org/news/2016-11-pluto-heart-cold-ice.html
Sputnik Planitia, a 1,000-kilometer wide basin within the iconic heart-shaped region observed on Pluto's surface,
could be in its present location because accumulation of ice made the dwarf planet roll over, creating cracks and
tensions in the crust that point towards the presence of a subsurface ocean.
Published in the Nov. 17 issue of Nature, these are the conclusions of research by James Keane, a doctoral student
at the University of Arizona's Lunar and Planetary Laboratory, and his adviser, assistant professor Isamu Matsuyama.
They propose evidence of frozen nitrogen pileup throwing the entire planet off kilter, much like a spinning top
with a wad of gum stuck to it, in a process called true polar wander.
"There are two ways to change the spin of a planet," Keane said. "The first—and the one we're all most familiar
with—is a change in the planet is a change in the planet's obliquity, where the spin axis of the planet is reorienting
with respect to the rest of the solar system. The second way is through true polar wander, where the spin axis remains
fixed with respect to the rest of the solar system, but the planet reorients beneath it."
