Images of Pluto captured by NASA's New Horizons mission while on a flyby of the dwarf planet in July 2015 are still yielding new previously unheard-of details and insights about Pluto and its moons.
In 2006 the celestial body was given dwarf planet status by the International Astronomical Union which developed a new definition for planets to which Pluto did not fit. A new analysis of the photos taken on that 2015 mission shows a region on the planet that is bumpy and doesn't appear to resemble other parts of the small dwarf planet.
Researchers said in their analysis that the region on Pluto is located southwest of Pluto's "heart" and called "Sputnik Planiti." It contains "multiple large domes" and the area rises up about 4 miles tall and is about 18 - 60 miles wide with "interconnected hills" and mounds along with depressions that cover the sides and tops of many of the formations and structures.
Kelsi Singer, senior research scientist at the Southwest Research Institute, which is located in Boulder, Colorado said, "We found a field of very large icy volcanoes that look nothing like anything else we have seen in the solar system."
Volcanic domes on the dwarf planet were studied and the two largest are called Wright Mons and Piccard Mons. Researchers say Wright Mons was determined to be similar in volume to the Mauna Loa volcano in Hawaii, which is one of the largest on Earth.
Singer said, "The way these features look is very different than any volcanoes across the solar system, either icy examples or rocky volcanoes."
"They formed as mountains, but there is no caldera at the top, and they have large bumps all over them," she said. "This means Pluto has more internal heat than we thought it would, which means we don't fully understand how planetary bodies work."
The researchers believe the ice volcanoes were formed in multiple different eras or "episodes" and were probably active about 100 million to 200 million years ago, which is considered young in geology.