A group of dome-shaped ice volcanoes that look different from anything else known in our solar system and possibly still active have been identified on Pluto using data from NASA’s New Horizons spacecraft, which shows that this remote icy world is more dynamic than which was previously known.
Scientists have said that these cryovolcanoes – which may number 10 or more – stand anywhere from 1 kilometer (six-tenths of a mile) to 7 kilometers (4-1 / 2 miles) high. Unlike volcanoes that emit gases and molten rock, this dwarf planet’s cryovolcanoes expel large amounts of ice – apparently frozen water rather than another frozen material – that can have the consistency of toothpaste, they said.
Characteristics of the asteroid belt dwarf planet Ceres, Saturn’s moons Enceladus and Titan, Jupiter’s moon Europa and Neptune’s moon Triton have also been pinned as cryovolcanoes. But they all differ from Pluto, the researchers said, due to different surface conditions such as temperature and atmospheric pressure, as well as different mixtures of icy materials.
“Finding these features does suggest that Pluto is more active, or geologically alive, than we previously thought it would be,” said planetary scientist Kelsi Singer of the Southwest Research Institute in Boulder, Colorado, lead author of the study. which was published this week in the journal Nature Communications.
“The combination of these features, which are geologically recent, cover a large area and most likely made of water ice, is surprising because it requires more internal heat than we thought Pluto would have at this stage of its history,” he said. Singer added.
Pluto, which is smaller than the Earth’s moon and has a diameter of about 2,380 kilometers (1,400 miles), orbits about 5.8 billion kilometers (3.6 billion miles) away from the sun, about 40 times further. as the Earth’s orbit. Its surface has plains, mountains, craters and valleys.
Images and data analyzed in the new study, obtained by New Horizons in 2015, confirmed previous hypotheses about cryovolcanism on Pluto.
The study not only found extensive evidence for cryovolcanism, but also that it lived a long time, not a single episode, said the planetary scientist from the Southwest Research Institute, Alan Stern, the New Horizons lead researcher and co-author of the study, said.
“What’s most fascinating about Pluto is that it is as complex – as complex as Earth or Mars despite its smaller size and high distance from the sun,” Stern said. “It was a real surprise of the New Horizons flight, and the new result on cryovolcanism highlights it again in a dramatic way.”
The researchers analyzed an area southwest of Sputnik Planitia, Pluto’s large heart-shaped basin filled with nitrogen ice. They found large domes 30-100 kilometers (18-60 miles) in diameter, which sometimes combined to form more complex shaped structures.
An elevation called Wright Mons, one of the highest, may have formed from several fused volcanic domes, giving rise to a shape unlike any other volcanoes. Although shaped differently, it is similar in size to Hawaii’s large volcano Mauna Loa.
Like the Earth’s and our solar system’s other planets, Pluto formed about 4.5 billion years ago. Based on an absence of impact craters that would normally accumulate over time, it appears that its cryovolcanoes are relatively recent – forming in the last few hundred million years.
“It’s young on a geological time scale. Because there are almost no impact craters, it’s possible that these processes are ongoing even today,” Singer said.
Pluto has very active geology, including flowing nitrogen ice glaciers and a cycle in which nitrogen ice evaporates during the day and condenses to ice at night – a process that constantly changes the planet’s surface.
“Pluto is a geological wonderland,” Singer said. “Many areas of Pluto are completely different. If you only had a few pieces of a Pluto puzzle, you would have no idea what the other areas looked like.”