New Horizons is closing in on the icy dwarf planet Pluto, and the spacecraft has returned its first images of the distant system. The pair of photographs were taken on January 25 and 27, and although they show just a pair of dots, Pluto and its largest moon Charon can be seen as the satellite orbits its frozen home world. New Horizons was roughly 125 million miles away from Pluto when the photograhs were recorded.
The Long Range Reconnaissance Imager (Lorri) was used to record the photos. Exposure time for the photographs was just one-tenth of a second. This was long enough to record Pluto and Charon, but not smaller satellites in the system. Astronomers know of five bodies orbiting Pluto so far, and it is likely New Horizons will discover additional, smaller worlds.
Clyde Tombaugh discovered Pluto in 1930. The first images of Pluto and Charon, taken by New Horizons, were released to celebrate the birthday of the astronomer, who was born February 4, 1906. Tombaugh passed away in 1997.
"This is our birthday tribute to Professor Tombaugh and the Tombaugh family, in honor of his discovery and life achievements - which truly became a harbinger of 21st century planetary astronomy," Alan Stern of the Southwest Research Institute, and principal investigator for New Horizons, said.
New Horizons was launched on January 19, 2006, and has traveled over three billion miles since that time. The spacecraft will continue to close in on Pluto and its moons, and images will become more detailed as the spacecraft approaches the system. Closest approach to Pluto will take place on July 15, 2015.
"Wednesday, July 15 should see two downlinks, one in the morning and one in the afternoon, with some really great photos - Pluto and Charon both filling the frame, the best picture of Nix, and a couple of high-res photos of sections of Pluto," Emily Lakdawalla of the Planetary Society said.
The $700 million mission to Pluto contains seven instruments to explore the distant system. Geology, surface composition and temperatures on the bodies will be measured before, during and after close approach. The new images are part of a optical navigation campaign being carried out by mission controllers.
"My dad would be thrilled with New Horizons. To actually see the planet that he had discovered and find out more about it, to get to see the moons of Pluto... he would have been astounded. I'm sure it would have meant so much to him if he were still alive today," Annette Tombaugh, Clyde Tombaugh's daughter, told the press.