"Oh, my God, look at that! There's considerably more than I thought. It looks enormous."The fly-by spacecraft used two cameras and an infrared spectrometer to record the event and its aftermath for 13 minutes, then turned away in "shield mode" as the comet passed by only 310 miles away, traveling at a relative speed of 23,000 miles per hour. The impactor carried a camera that sent back crystal-clear pictures of ridge-like features, apparent craters and sinkholes and other pockmarks that grew to dominate its field of vision as the spacecraft closed in on the comet at 6.4 miles per second. The last image was sent only three seconds before the crash.
"It was just phenomenal, we didn't have to exercise one contingency plan. We're minus one spacecraft, the impactor has been totally vaporized."The fly-by spacecraft emerged 40 minutes after impact none the worse for its close encounter with the comet. Besides the spacecraft images, a network of about 60 Earth- and space-based telescopes, along with thousands of amateur astronomers, were standing by to participate in the first-ever globally coordinated effort to watch an object dig a crater in a comet. By assessing the shape and size of the crater and chemically analyzing the debris that belched from it, scientists hope to gain new insights into the composition of the solar system at the time of its formation 4.5 billion years ago. Comets periodically migrate in from deep space, their outer layers burning away as they approach the sun. To get to the ancient material within, Deep Impact needed to punch through the boiling crust. Deep Impact, with the impactor attached to the fly-by spacecraft, was launched January 12 for an Independence Day rendezvous with Tempel 1, about 83 million miles away and hurtling through space at 66,000 mph. Early Sunday morning, the spacecraft was 547,000 from the comet, traveling in the same direction, but at 43,000 mph. If everything went as planned, the Manhattan Island-sized comet would overtake the 820-pound impactor like an express train. At 2:07 a.m. EDT Sunday, the fly-by spacecraft released the impactor, then did a 14-minute "divert burn" to take it out of harm's way and put it into position to watch its erstwhile companion be obliterated 24 hours later.