When NASA’s New Horizons cruises by Pluto in 2015, the images it captures could help astronomers determine if an ocean is hiding under the frigid surface, opening the door to new possibilities for liquid water to exist on other bodies in the solar system. New research has not only concluded such an ocean is likely, but also has highlighted features the spacecraft could identify that could help confirm an ocean’s existence.
The easiest feature to identify would appear if no ocean existed.
As spherical bodies spin, their angular momentum tends to push material towards the equator, forming a bulge. If Pluto boasts a liquid layer, the ice would flow, reducing such a protrusion. Thus, the appearance of a “frozen-in” primordial bulge, left over from when Pluto spun more rapidly, would signify a lack of ocean.
“If the bulge is present, it will be about 6 miles (10 km) high, so it should be readily detectable,” Nimmo said.
New Horizons will map the entire sunlit surface of Pluto,” Weaver explained, “but only the hemisphere facing the spacecraft near the time of the flyby will be mapped at the highest resolution.”
The highest resolution will capture 62 meters per pixel when the craft is within 7,750 miles (12,500 km). However, the more distant images still will be approximately ten times more detailed than those captured by the Hubble Space Telescope.
Ridges and valleys with heights and depths of 260 feet (80 meters) should be distinguishable.