A fleet of spacecraft took aim at Halley's Comet in 1986, providing the first close-up look at any comet. The best views came from Giotto, a European craft, which snapped this picture (which has been color-enhanced) just a few minutes before its closest encounter. It shows streams of gas and dust flowing away from the comet, pushed by sunlight and the solar wind. [ESA]
Find out more in our radio program entitled Assault on a Comet.