Pluto's peaks formed by many ice volcanoes, study says

March 29 (UPI) -- A merger of many ice volcanoes form Pluto's two mane mountains, a study published Tuesday in Nature Communications reveals -- and what they've found suggests the planet is an ocean world, despite its great distance from the Sun.

Pluto has two mountains, Wright Mons and Piccard Mons, which scientists suspected were volcanoes that spewed icy slush in a cryovolcanic eruption process instead of molten rock.

Though no cauldron-like caldera could be seen, new analysis of images and topographical data suggest that each of the mountains formed from a merger of many ice volcanoes instead of just being two big volcanoes.

"It's considered kind of a big claim to have icy volcanism," study lead author Dr. Kelsi Singer told The Guardian.

"It's theoretically possible, but there aren't a ton of other examples in the solar system, and they are all really different looking, and do not look like the features on Pluto," said Singer, a co-investigator in NASA's New Horizons mission.

Scientists first spotted close-up images of Pluto when NASA's New Horizons spacecraft flew past it in July 2015, and since then, many more images have arrived.

These images were used to conclude the dwarf planet "was resurfaced by cryovolcanic processes, a type and scale so far unique to Pluto," according to the new study.

Researchers also spotted evidence of recent eruption of ice lava from cryovolcanoes, and suggested that this could be driven by an underground ocean body.

"We tried to find some other way to explain it, but we just really couldn't," Singer, also a senior research scientist at the Southwest Research Institute in Boulder, Colo., told The New York Times.