06.15.2006
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| Two views of asteroid 2002JF56 from the New Horizon's Ralph imager. |
Speeding toward Pluto, the New Horizons spacecraft used asteroid 2002 JF56 to test its ability to track and image a rapidly moving object. On June 13 New Horizons came to within about 62,000 miles of the tiny space rock, providing a flight test opportunity for the mission operations team to prepare for the February 2007 fly by of Jupiter and ultimately the 2015 encounter with Pluto.
The photo is a composite of two images snapped by the Multispectral Visible Imaging Camera (MVIC) component of the Ralph imager, taken from 833,000 miles and 2.1 million miles. The asteroid, with an estimated diameter of about 1.5 miles, appears as a bright, barely resolved pinpoint of light against the background of space. The captured images demonstrate that Ralph can track and photograph objects moving relative to New Horizons - just as Jupiter and its moons and Pluto and its moons will be. This capability is critical as New Horizons closes in on Jupiter for a gravity boost toward the Pluto system.
"Ralph has performed flawlessly since the launch of New Horizons and these asteroid observations are giving us more insight into the ultimate sensitivity and capability of the instrument," says Ralph Instrument Scientist Dennis Reuter, of NASA Goddard Space Flight Center, Greenbelt, MD. "They are allowing us to use Ralph to view and track a single fast-moving object as it changes from a dim speck of light in a bright star field to a body whose brightness rivals that of Jupiter at the high resolution that Ralph is capable of."
Launched last Jan. 19, New Horizons is currently 176 million miles from Earth, moving about the Sun at about 17 miles per second. The spacecraft is on course to fly through the Jupiter system for science studies and a gravity assist, with closest approach to the giant planet set for Feb. 28, 2007.
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