It's been 18 years since Clyde Tombaugh, Pluto's discoverer, passed away — but on Wednesday the late astronomer got a birthday present that would have made him beam with joy: the closest close-ups ever taken of the dwarf planet, delivered by NASA's New Horizons probe.
"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," New Horizons principal investigator Alan Stern, a planetary scientist at the Southwest Research Institute, said Wednesday in a news release about the images.
The pictures, taken on Jan. 25 and Jan. 27, were the first views of Pluto acquired during an imaging campaign that will climax on July 14 with the first-ever flyby of that icy mini-world, 3 billion miles from the sun.
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New Horizons is still roughly 126 million miles (203 million kilometers) away from Pluto — which means the dwarf planet and its largest moon, Charon, show up as mere dots. But the view is due to improve in the months ahead: By May, the pictures taken by New Horizons' LORRI camera should outdo the best that the Hubble Space Telescope can manage.
These pictures are meant primarily to help the New Horizons team adjust the spacecraft's course. On the basis of radio data, navigators already know they''ll need to make a slight course correction — something on the order of 1 meter per second (2.2 mph) in velocity, Stern said. Getting a visual fix will improve the accuracy of the adjustment, for next month's scheduled engine maneuver as well as course corrections to come.
"This is the beginning of a torrent of images between now and June, homing in for the encounter," Stern told NBC News. By the end of June, the New Horizons team expects to take more than 1,000 pictures of Pluto, he said.
"Of course dad would be thrilled about the New Horizons mission, and about the success to date of that mission," Tombaugh's son, Alden Tombaugh, said in a NASA video. "He always wanted to know more about everything that was out there."
In a sense, Clyde Tombaugh is part of the mission: A smattering of Clyde Tombaugh's ashes was included as a payload on the spacecraft, with an inscription hailing him as the "discoverer of Pluto and the solar system's 'third zone.'"