The Stardust-NExT team aims to get closer looks at these features in hopes of piecing together that history.
My how you've changed
Researchers want to compare images of the surface they gather with those beamed back from Deep Impact. The goal is to gauge the effects the comet's intervening travels have had on the nucleus.
And, if the craft and comet are oriented in just the right way, the crater generated by the Deep Impact projectile should be visible.
Tempel 1's nucleus is 4.7 miles long and 3 miles across at its widest point. The comet was discovered in 1867, but after several observations over the following 12 years, the comet seemed to vanish. It reappeared on astronomers photographic plates in 1967.
Astronomers traced Tempel 1's nearly century-long disappearance to changes Jupiter imposed on the comet's orbit.
Two close encounters with Jupiter toward the middle of the 20th century tweaked the comet's orbit again, giving it a return time of once every 5.5 years. The comet orbits the sun twice for every orbit Jupiter makes. And it moves from near Jupiter's orbit at its greatest distance from the sun to near the orbit of Mars as it swings behind the sun and heads back on its return trip.
The Stardust-NExT spacecraft has piled up mileage in it own right, logging some 3.7 billion miles since its launch as the Stardust mission in February 1999. Stardust sped through the cloud of dust and gas that surrounds the comet Wild 2 in January 2004, scooped up samples of the detritus, then headed back to Earth. As it sped past Earth in January 2006, it dropped off a capsule containing the samples, delivering the first pristine cometary material humans have ever had a chance to examine.