Like icebergs floating in the Arctic Ocean of the Earth, so Pluto has “hills” of water ice floating around the ocean of frozen nitrogen.
In the new photographs obtained during the NASA New Horizons space mission, which took place near the dwarf planet on July 14, 2015, an interesting detail was added to the already known Plain Satellite of Pluto, a relief in the western part of the heart-shaped Tombo Region. Planetary scientists are still studying the results of observations in detail, but have already made some interesting preliminary discoveries, one of which is an amazing movement on Pluto’s ice.
Plain Sputnik, as it is known, contains a large amount of nitrogen ice, which gives the region a smooth view against the “coast” of rocky mountains. But this does not mean that the ice can not move. The physical properties of ice in the rest of the Solar System are very different from those we are used to on Earth. The ocean of nitrogen is in constant motion, although very slow. Millions of years, as is commonly believed, the ices of the Plains Sputnik circulate like old lava-lamps, creating a complex picture of convective cells. Among the “open sea” of nitrogen ice, huge chunks of water ice were seen. Water ice is less dense than nitrogen ice, and floats in a style unlike the icebergs navigate in our oceans. Essentially, the pictures of the New Horizons show a pattern of migration of huge hills of water ice, gathering in groups and drifting towards the edges of the convective cell of nitrogen ice.
“These hills are probably pieces of rocky hills that broke away and fell on the nitrogen glaciers of the Plains of the Sputnik,” wrote NASA New Horizons in the news feed.
In addition, in large areas in the northern part of the Sputnik Plain, icebergs gather from water ice, which appear to have “spilled onto the shore” on their own. Floating on the surface of the nitrogen ice, they collided with other pieces and gathered in one place. This terrain, nearly 40 miles wide, is named by the New Horizons “Challenger Coles” team, in honor of the crew of the Space Shuttle Challenger, which exploded immediately after the launch 30 years ago.