In order to test its tracking and imaging capabilities, the probe tracks and photographs asteroid 2002 JF56 in the asteroid belt coming to within 102,000 km. The asteroid is about 2.5 km in diameter.
The asteroid observation was a flight test, a chance for us to test the spacecraft’s ability to track a rapidly moving object and to refine our sequencing process. The objects we will observe this winter in the Jupiter system will appear to be moving across the sky much more slowly than this asteroid, so these observations were an unexpected opportunity to prepare for the even faster tracking rates we’ll experience in summer 2015, when the spacecraft zips through the Pluto system at more than 31,000 miles per hour.
The probe is now 283 million km (176 million miles) from Earth traveling at 27 km (17 miles) per second relative to the sun.