Movie shows close-up of Pluto’s varied surface; unusual fretted terrain discovered
Using the highest resolution images of Pluto’s encounter hemisphere, NASA’s New Horizons team has released a movie showing a stunning close-up of that region’s varied terrains.
The mosaic strip used to create the movie has a resolution of 260 feet (80 meters) per pixel. It was composed of images obtained by the Long Range Reconnaissance Imager (LORRI) about 23 minutes before the July 14, 2015, closest approach from a distance of about 9,850 miles (15,850 kilometers).
Viewers can zoom in on any area to see maximum detail. The close-ups are a boon to mission scientists because it enables them to see a level of detail on Pluto’s varied terrains that will provide key insights into the processes that created and shaped those terrains. For members of the public, it is a rare opportunity to see an impressive view of a complex, distant world.
Starting with the “limb” of Pluto, the movie takes viewers across the surface and almost to the terminator, which separates its day and night sides, at the hemisphere’s southeast. As the video moves across the planet’s surface, the perspective changes from a horizontal view of the northern end at the beginning to a vertical look downward at its southern end.
At its northern end, the mosaic strip is about 55 miles (90 kilometers) wide. It narrows to a diameter of 45 miles (75 kilometers) at its southern side.
Moving from top to bottom, the video showcases new, closer views of Pluto’s many terrains, including hilly and cratered uplands; ridged terrain; angular, blocky mountain ranges; smooth, polygonal nitrogen ice plains; pitted, non-cellular regions of nitrogen ice; pitted hilly plains of nitrogen ice, and rugged, dark highlands.
While the individual photos are not new, this release marks the first time they have been combined to create a movie.
“This new image product is just magnetic,” stated New Horizons Principal Investigator Alan Stern of the Southwest Research Institute (SwRI) in Boulder, Colorado.
“It makes me want to go back on another mission to Pluto and get high-resolution images like these across the entire surface.”
Because the spacecraft was traveling so fast, it could obtain such high-resolution images from only one hemisphere. Photos were taken of the other, non-encounter hemisphere, but their resolution is much lower.
Video courtesy of NASA
The most recent still images released depict an area on the upper left of Pluto’s encounter side informally named Venera Terra, which is composed of a rare, “fretted” terrain in the form of polygonal blocks linked by networking valleys with diameters of several miles (between three and four kilometers). Although the polygonal blocks are bright, the regions connecting them are dark.
This type of terrain is seen nowhere else on Pluto and in just one other location in the Solar System—a region on Mars known as Noctis Labyrinthus, a network of valleys on the western side of Vallis Marineris, a vast canyon system.
Impact craters with diameters up to 15 miles (25 kilometers) dot Venera Terra, leading scientists to determine the surface is ancient. The network of valleys was likely created by a past fracturing of Pluto’s surface, scientists theorize.
“The distinct interconnected valley network was likely formed by extensional fracturing of Pluto’s surface,” according to a NASA statement. “The valleys separating the blocks may then have been widened by movement of nitrogen ice glaciers, or flowing liquids, or possibly by ice sublimation at the block margins.”
Images of the region were taken by New Horizons’ Ralph / Multispectral Visible Imaging Camera (MVIC) with a resolution of 2,230 feet (680 meters) per pixel, at a distance of 21,100 miles (33,900 kilometers) just 45 minutes before closest approach.
Interestingly, compositional data from Ralph/MVIC indicates Venera Terra’s bright polygonal blocks have a high methane ice content. At Pluto’s surface temperatures, methane ice is subject to sublimation.
Both images on the left are of Venera Terra. The bottom one uses false purple color on areas rich in methane ice.
In a second blog entry titled “Behind the Lens at New Horizons’ Pluto Flyby”, New Horizons science team member Henry Throop describes how he photographed members of the science team as they viewed their first close-up images of Pluto during last July’s flyby.
He notes the first images of Pluto by LEISA, New Horizons‘ near-infrared spectrometer, were snapped just two weeks before closest approach.
These pictures, which provided the first confirmation of water ice on Pluto’s surface, had to be analyzed independently by three members of the composition team to assure the findings were accurate.
More images and videos of Pluto’s surface are regularly being made available to the public.
The New York Times Virtual Reality project just released a video titled “Seeking Pluto’s Frigid Heart“, which is available for viewing on Androids and iPhones by downloading the free NYT VR app.
On May 31, the US Postal Service will release stamps depicting full-disk images of the Solar System’s planets in two sets. One set, “Views of Our Planets”, shows images of the four terrestrials and four gas giants, while the other focuses specifically on Pluto, featuring the statement: “Pluto—Explored!”
That statement is a response and follow-up to a 1991 set of Solar System stamps, which showed real images of the terrestrials and Jovians but depicted Pluto with the phrase “Not Yet Explored”. A copy of that stamp was placed on board New Horizons.
A dedication ceremony for the release of both sets of stamps will take place May 31 at the World Stamp Show-NY 2016.
The “Views of Our Planets” stamps will be available for purchase in post offices or online while the Pluto Explored stamps can be bought only online or by calling 800-782-6724.
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.