WHEN the Stardust spacecraft plunged through the coma of comet Wild 2 on 2 January, it was in much greater danger than anyone had suspected.
Stardust’s unprecedented close-up look at the inner regions of the dust and gas cloud, or coma, surrounding the comet’s nucleus revealed that Wild 2’s jets are far more numerous and contain far larger solid chunks than most scientists had guessed.
At the high speed of the encounter, around 22,000 kilometres per hour, these larger pieces could easily have smashed into the craft and left it disabled and perhaps wrecked, the mission’s chief scientist, Donald Brownlee,…
