Nearly 16 years after it was declared unfit to be a planet, it seems Pluto still has the power to pull us back into the mysteries it’s hiding on the surface. A new study now hints at mysterious volcanoes of ice being spotted on the surface, the likes of which are not seen anywhere else in the solar system.
Led by astronomers from the New Horizons mission, the team has detected a region of large domes and rises flanked by hills, mounds, and depressions formed by material expelled from below the surface of this distant, icy planet. The creation of this terrain requires multiple eruption sites and a large volume of material that are multiple, several-km-high domes, some of which merge to form more complex platforms.
The study published in the journal Nature Communications states that modeling suggests a subsurface water-rich ocean could potentially persist on Pluto existing nearly 100200km or more below the surface of the distant planet, the base of the icy shell. The New Horizons mission had imaged a region dominated by two large mounds known as Wright Mons and Piccard Mon, which is now believed to be cryovolcanoes.
PLUTO IS ALIVE
Led by Dr. Kelsi Singer, New Horizons Deputy Project Scientist from the Southwest Research Institute, the team analyzed the geomorphology and composition of an area located southwest of Pluto’s bright, icy “heart,” Sputnik Planitia. This cryovolcanic region contains multiple large domes, ranging from 1 to 7 kilometers tall and 30 to 100 or more kilometers across, that sometimes merge to form more complex structures.
“The particular structures we studied are unique to Pluto, at least so far. Rather than erosion or other geologic processes, cryovolcanic activity appears to have extruded large amounts of material onto Pluto’s exterior and resurfaced an entire region of the hemisphere New Horizons saw up close,” Singer said in a statement.
Because these are young geologic terrains and large amounts of material were required to create them, it is possible that Pluto’s interior structure retained heat into the relatively recent past, enabling water-ice-rich materials to be deposited onto the surface. Other geologic processes considered to create the features are unlikely, according to the team.
NEW HORIZONS UNLOCKED
The images were obtained from the New Horizons mission in 2015, revealing diverse geological features populating Pluto, including mountains, valleys, plains, and glaciers. The terrain raised curiosity among scientists since the frigid temperatures at Pluto’s distance were expected to produce a frozen, geologically inactive world.
“One of the benefits of exploring new places in the solar system is that we find things we weren’t expecting. These giant strange-looking cryovolcanoes observed by New Horizons are a great example of how we are expanding our knowledge of volcanic processes and geologic activity on icy worlds,” Singer added.
The New Horizons mission was launched by Nasa in 2006, the same year Pluto was downgraded to dwarf status. It remains the sole spacecraft to explore Pluto and its moons after it reached the icy planet in 2015. The spacecraft has been exploring objects in the Kuiper Belt, a region of the solar system that extends from about 30 AU, near the orbit of Neptune, to about 50 AU from the Sun.