Using images of Pluto’s surface, geologists with the New Horizons mission have discovered that two of dwarf planet’s mountains could be cryovolcanoes – exotic volcanoes that erupt volatiles such as water, ammonia or methane, instead of molten rock.
This high-resolution image of Pluto was taken by New Horizons on July 14, 2015: yellow circle shows location of Wright Mons and Piccard Mons mountains on the dwarf planet. Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute.
The two cryovolcano candidates, named Piccard Mons and Wright Mons, are huge features measuring tens of miles across and several miles high.
“These are big mountains with a large hole in their summit, and on Earth that generally means one thing — a volcano,” explained New Horizons team member Dr Oliver White, of NASA’s Ames Research Center.
“If they are volcanic, then the summit depression would likely have formed via collapse as material is erupted from underneath,” he said.
“The strange hummocky texture of the mountain flanks may represent volcanic flows of some sort that have traveled down from the summit region and onto the plains beyond, but why they are hummocky, and what they are made of, we don’t yet know.”
While the appearance of Piccard Mons and Wright Mons is similar to volcanoes on our planet that spew molten rock, Pluto’s cryovolcanoes are expected to emit substances such as water ice, nitrogen, ammonia, or methane.
If Pluto proves to have cryovolcanoes, it will provide a new clue to its geologic and atmospheric evolution.
New Horizons team discovered that Wright Mons and Piccard Mons mountains on Pluto could be ice volcanoes: the color in the right panel depicts changes in elevation, blue indicating lower terrain and brown showing higher elevation; green terrains are at intermediate heights. Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute.
“The New Horizons flyby of Pluto in July 2015 has provided the first few close-up images of the Kuiper belt object, which reveal it to have a highly diverse range of terrains, implying a complex geological history,” Dr White and his colleagues said.
“The highest resolution images that have yet been returned are seven lossy 400 meters/pixel frames that cover the majority of the prominent Plutonian feature informally named Sputnik Planum, and its surroundings. This resolution is sufficient to allow detailed geomorphological mapping of this area to commence.”
“The New Horizons mission has taken what we thought we knew about Pluto and turned it upside down. It’s why we explore – to satisfy our innate curiosity and answer deeper questions about how we got here and what lies beyond the next horizon,” added Jim Green, Director of NASA’s Planetary Science Division.
The scientists reported their results November 10 at the 47th Annual Division for Planetary Sciences Meeting in National Harbor, Maryland.
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Oliver White et al. 2015. Geomorphological Mapping of Sputnik Planum and Surrounding Terrain on Pluto. 47th Annual Division for Planetary Sciences Meeting. Abstract # 210.06
