New Horizons’ images show Pluto’s snakeskin terrain in 3-D
The mission team of NASA’s New Horizons spacecraft has released a 3-D stereo image of Pluto’s “snakeskin” or bladed terrain, located to the east of the Tombaugh Regio heart-shaped area.
This latest picture is composed of two images taken by the Ralph/Multispectral Visible Imaging Camera (MVIC) approximately 14 minutes apart on the day of closest approach.
Unlike anything observed in the Solar System, this region, informally named Tartarus Dorsa, is composed of sharp ridges or blades hundreds of feet high, lined from north to south, and spaced several miles apart from one another. The “blades” sit on top of round ridges bordered by flat valley areas and stretch out a long way eastward.
A view of the image with 3-D glasses reveals the extent of this terrain’s strangeness.
The best resolution of the Ralph/MVIC images is around 1,000 feet (310 meters). The first image was taken 16,000 miles (25,000 km) from Pluto, while the second image was captured at a distance of 10,000 miles (approximately 17,000 km) on July 14, 2015.
Mission team members have several theories about the terrain’s origin. Some speculate it was formed by the deposit of methane ices, whereas others think it is the result of erosion caused when surface ices evaporated.
In a blog – Pluto’s ‘Snakeskin’ Terrain: Cradle of the Solar System? – dated March 11, 2016, New Horizons science team member Orkan Umurhan, a mathematical physicist and senior post-doc at NASA Ames Research Center, suggests that the bladed terrain is composed of ancient materials from the proto-solar nebula that formed the Solar System.
Umurhan theorizes that this terrain could actually be made up of a substance known as methane clathrates, which can exist as ice only in very cold temperatures. The terrain contains some of Pluto’s steepest features and is shown by New Horizons’ Linear Etalon Imaging Spectral Array (LEISA) instrument to be composed largely of methane along with some water ice.
On Earth, the only places cold enough to harbor methane clathrates are deep ocean floors.
However, on Pluto, which has surface temperatures ranging from –300 °F to –400 °F (–184 °C to –240 °C) , methane clathrates could do more than exist on the surface; they could also provide support to the bladed terrain.
While there is no evidence to confirm Tartarus Dorsa is made up of methane clathrates, the possibility of their presence on Pluto’s surface raises questions as to how they got there.
According to studies cited by Umurhan, methane clathrates in the Kuiper Belt and on the outer Solar System’s icy moons formed within the proto-solar nebula, meaning that they existed before the Solar System had formed.
Along with the 3-D image, the mission team released a global picture (shown right) of Pluto created by combining a Ralph/MVIC color scan with a monochrome photo taken by the Long Range Reconnaissance Imager (LORRI). Both images were captured on July 13, 2015, one day before closest approach, from a range of one million miles (1.6 km).
The MVIC scan has a resolution of 20 miles (32 km) per pixel, whereas the LORRI image has one of five miles (eight km) per pixel.
Highlighted in red is the mysterious Tartarus Dorsa with the bladed terrain, extending eastward from Tombaugh Regio.
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.