Pluto probe’s camera sees striking geologic boundary

A newly discovered mountain range lies near the southwestern margin of Pluto’s Tombaugh Regio (Tombaugh Region), situated between bright, icy plains and dark, heavily-cratered terrain. This image was acquired by New Horizons’ Long Range Reconnaissance Imager (LORRI) on July 14, 2015 from a distance of 48,000 miles (77,000 kilometers) and sent back to Earth on July 20. Features as small as a half-mile (1 kilometer) across are visible. Credit: NASA/JHUAPL/SWRI
A newly discovered mountain range lies near the southwestern margin of Pluto’s Tombaugh Regio (Tombaugh Region), situated between bright, icy plains and dark, heavily-cratered terrain. This image was acquired by New Horizons’ Long Range Reconnaissance Imager (LORRI) on July 14, 2015 from a distance of 48,000 miles (77,000 kilometers) and sent back to Earth on July 20. Features as small as a half-mile (1 kilometer) across are visible. Credit: NASA/JHUAPL/SWRI

New views of Pluto’s unexpectedly complicated landscapes are coming back to Earth, revealing stark intersections between freshly-made bright icy plains and heavily-cratered darker terrain.

One image from the New Horizons spacecraft’s telescopic black-and-white camera appears to show a clash of geologic units. On the left, impact craters dot a patch of older, darker material. On the right, a brighter ice field is criss-crossed with troughs and veins and a mountain range as high as the Appalachian Mountains in the eastern United States, a tapestry of topography that appears to resemble some sites in Antarctica.

The mountains are just west of the Sputnik Planum region in Pluto’s heart, an area informally named Tombaugh Regio after astronomy Clyde Tombaugh, who discovered the distant icy dwarf in 1930. Scientists discussed the first up-close view of Sputnik Planum, which appears to be made of blocks of ice, during a press conference Friday.

The newly-discovered peaks are about 68 miles, or 110 kilometers, northwest of Norgay Montes, a string of higher mountains as big as the Rocky Mountains revealed in images last week.

“There is a pronounced difference in texture between the younger, frozen plains to the east and the dark, heavily-cratered terrain to the west,” said Jeff Moore, leader of the New Horizons geology, geophysics and imaging team at NASA’s Ames Research Center in California. “There’s a complex interaction going on between the bright and the dark materials that we’re still trying to understand.”

“While Sputnik Planum is believed to be relatively young in geological terms — perhaps less than 100 million years old — the darker region probably dates back billions of years,” NASA said in a statement accompanying the image release. “Moore notes that the bright, sediment-like material appears to be filling in old craters (for example, the bright circular feature to the lower left of center).”

Another press briefing updating the science results from the July 14 flyby is scheduled for Friday, July 24.

The image has a resolution of about a half mile, or approximately a kilometer. Moore says almost all of Pluto’s sunlit hemisphere at the time of the New Horizons encounter was to be imaged at comparable half-mile resolution, but all the photos will not arrive on Earth until next year due to the low-speed, 2-kilobit per second data rate between the ground and the faraway space probe.

The snapshots currently coming down from New Horizons are compressed, and the spacecraft could start broadcasting raw files this fall.

The sharpest imagery from New Horizons’ flyby, which could spot features smaller than a football field, is still stored in the probe’s data recorders awaiting downlink to Earth.

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Follow Stephen Clark on Twitter: @StephenClark1.