Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.The newly-released images were captured in early to mid-April from within 70 million miles (113 million kilometres), using the telescopic Long-Range Reconnaissance Imager (LORRI) camera on New Horizons. A technique called image deconvolution sharpens the raw, unprocessed images beamed back to Earth. New Horizons scientists interpreted the data to reveal the dwarf planet has broad surface markings — some bright, some dark — including a bright area at one pole that may be a polar cap.
This movie (click to see an enlarged view) shows a series of LORRI images of Pluto and Charon taken at 13 different times spanning 6.5 days, from April 12-18th, 2015. During that time, the spacecraft’s distance from Pluto decreased from about 69 million miles (111 million kilometres) to 64 million miles (104 million kilometres). Pluto is kept fixed in the frame. The 3x-magnified view of Pluto highlights the changing brightness across the disc of Pluto as it rotates. Because Pluto is tipped on its side (like Uranus), when observing Pluto from the New Horizons spacecraft, one primarily sees one pole of Pluto, which appears to be brighter than the rest of the disc in all the images. Scientists suggest this brightening in Pluto’s polar region might be caused by a “cap” of highly reflective snow on the surface. The “snow” in this case is likely to be frozen molecular nitrogen ice. New Horizons observations in July will determine definitively whether or not this hypothesis is correct. In addition to the polar cap, these images reveal changing brightness patterns from place to place as Pluto rotates, presumably caused by large-scale dark and bright patches at different longitudes on Pluto’s surface. In all of these images, a mathematical technique called “deconvolution” is used to improve the resolution of the raw LORRI images, restoring nearly the full resolution allowed by the camera’s optics and detector. Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.“As we approach the Pluto system we are starting to see intriguing features such as a bright region near Pluto’s visible pole, starting the great scientific adventure to understand this enigmatic celestial object,” says John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “As we get closer, the excitement is building in our quest to unravel the mysteries of Pluto using data from New Horizons.”
Also captured in the images is Pluto’s largest moon, Charon, rotating in its 6.4-day long orbit. The exposure times used to create this image set — a tenth of a second — were too short for the camera to detect Pluto’s four much smaller and fainter moons.
Since it was discovered in 1930, Pluto has remained an enigma. It orbits our Sun more than 3 billion miles (about 5 billion kilometres) from Earth, and researchers have struggled to discern any details about its surface. These latest New Horizons images allow the mission science team to detect clear differences in brightness across Pluto’s surface as it rotates.
“After travelling more than nine years through space, it’s stunning to see Pluto, literally a dot of light as seen from Earth, becoming a real place right before our eyes,” said Alan Stern, New Horizons principal investigator at Southwest Research Institute in Boulder, Colorado. “These incredible images are the first in which we can begin to see detail on Pluto, and they are already showing us that Pluto has a complex surface.”Image credit: Alan Stern/NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.The images the spacecraft returns will dramatically improve as New Horizons speeds closer to its July rendezvous with Pluto.
“We can only imagine what surprises will be revealed when New Horizons passes approximately 7,800 miles (12,500 kilometres) above Pluto’s surface this summer,” said Hal Weaver, the mission’s project scientist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.
Data collected by NASA’s New Horizons probe and ESA’s Rosetta mission suggest Pluto might have formed from the accretion of a billion or so smaller bodies similar to Comet 67P/Churyumov-Gerasimenko and other Kuiper Belt objects.
NASA’s Dawn spacecraft is now less than two months away from capture into orbit around Ceres for a 16-month study of the dwarf planet — and its cameras are already revealing tantalising surface details.
It is almost five months since New Horizons’ epic encounter with Pluto, but the captured images and data will stream back to Earth across 3 billion miles of interplanetary space for a further 11 months. The first in a series of the best close-ups of the dwarf planet that humans may see for decades have been released, obtained when the spacecraft was just 15 minutes before closest approach during the 14 July flyby.
