Pluto's Mysterious Floating Hills Mesmerize Scientists

— -- The New Horizons probe has yielded a trove of new information about Pluto, including the existence of miniature hills that appear to be floating across the surface of the dwarf planet.

The hills, which are made of water ice, measure anywhere from one to several miles across and are located in Pluto's heart-shaped feature, according to photos and data analyzed by NASA.

"Because 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," a NASA blog post explained.

It's believed the hills are fragments of Pluto's uplands that have been carried by nitrogen-rich glaciers into Pluto's flat Sputnik Planum region. NASA also observed chains of the floating hills along the flow paths of the glaciers.

The photo is the latest to be released as New Horizons continues to send a trove of data and photos from its July 14 flyby of Pluto back to Earth. With data downlinking at a rate of about 1 to 4 kilobits per second, it's expected the entire trove of science will take one year to be transmitted back to Earth.

Launched in January 2006 on a 3-billion-mile journey to Pluto, New Horizons "phoned home" after its Pluto flyby, indicating that it had successfully navigated just 7,700 miles from the dwarf planet. It later sent back the first high-resolution images of Pluto's surface.

New Horizons conserved energy by taking "naps" during the monumental trip. The spacecraft, equipped with a battery that converts radiation from decaying plutonium into electricity, may have enough power for two more decades of exploration, according to NASA.

The piano-sized probe is speeding through the Kuiper Belt, an area at the edge of the solar system encompassing Pluto and a vast area of tiny, icy worlds.