IT WAS a celestial fireworks display that left even NASA speechless. After travelling for 172 days and 431 million kilometres, the agency’s Deep Impact spacecraft smashed into comet Tempel 1 on 4 July at a speed of 36,800 kilometres per hour. And for a few spectacular moments, the debris shone six times brighter than the comet’s nucleus.
“Jeez! And we thought it was going to be subtle,” exulted Don Yeomans of NASA’s Jet Propulsion Laboratory in Pasadena, California. “That was considerably brighter, and more material came out, than I had expected.” Team member Peter Schultz of Brown University in Providence, Rhode Island, says the results…
