Pluto’s bladed terrain has snow, ice features similar to those on Earth
Scientists using a computer model, much like those used to study Earth’s climate, have identified bowl-shaped ridges in Pluto’s bladed or “snakeskin” terrain that resemble similar structures on Earth.
Led by John Moores of Toronto’s York University, the researchers studied New Horizons’ images of ridges in the region of Pluto known as Tartarus Dorsa and determined the ridges are depressions, known as penitentes, formed by erosion.
Computer simulations showing the processes of evaporating ices helped the researchers identify the penitentes, marking the first time such features have been found beyond Earth.
Blade-shaped spires, rising as high as 1,600 feet (500 meters), sit at the edges of the penitentes – which are much larger than those on Earth – with separations of two to three miles (3–5 kilometers) between them.
“This gargantuan size is predicted by the same theory that explains the formation of these features on Earth,” Moores said. “In fact, we were able to match the size and separation, the direction of the ridges, as well as their age: three pieces of evidence that support our identification of these ridges as penitentes.”
Pluto’s penitentes likely formed within the last several tens of millions of years.
The fact that these features have, so far, been found only on Earth and Pluto, but not on icy moons or dwarf planets that have no atmospheres, is a probable indication that an atmosphere as well as low temperatures must be present for the ridges to form.
Because the atmospheres of Earth and Pluto are very different, the scale of the penitentes on the two worlds is also very different.
“Exotic differences in the environment give rise to features with very different scales,” Moore noted. “This test of our terrestrial models for penitentes suggests that we may find these features elsewhere in the Solar System, and in other solar systems, where the conditions are right.”
Even though Pluto is much colder than Earth, more distant from the Sun, has a thinner atmosphere, and has snow and ice made of nitrogen and methane rather than water, the same physics applies when it comes to the formation of these ridges.
Scientists at the NASA Goddard Space Flight Center and the Johns Hopkins University Applied Physics Laboratory (JHUAPL) took part in the study, whose results are published in the journal Nature.
Moore credited the discovery of Pluto’s penitentes to information about Pluto’s atmosphere obtained via climate models like those used by meteorologists on Earth, which were provided to his team by NASA and JHUAPL.
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.