NASA’s New Horizons spacecraft doesn’t pass Pluto until July 14th — zipping by about 7,800 miles (12,500 kilometres) above the surface of the dwarf planet after a journey of almost 3 billion miles — but the mission team is making tantalising new discoveries as the piano-sized probe bears down on the Pluto system.
NASA’s New Horizons spacecraft spied extensional faults on Pluto, a sign that the dwarf planet has undergone a global expansion possibly due to the slow freezing of a sub-surface ocean. A new analysis by Brown University scientists bolsters that idea, and suggests that ocean is likely still there today.
The nitrogen ice glaciers on Pluto appear to carry an intriguing cargo: numerous, isolated hills that may be fragments of water ice from Pluto’s surrounding uplands. Since water ice is less dense than nitrogen-dominated ice, scientists believe these water ice hills are floating in a sea of frozen nitrogen and move over time like icebergs in Earth’s Arctic Ocean.