The European Space Agency’s unmanned Giotto space probe makes its closest approach to the nucleus of Halley’s Comet, coming within 400 miles of the comet’s core and taking unprecedented photos that help scientists refine their theories about cometary composition and formation. Giotto pays for the close encounter by taking a beating: its instruments register significant dust impacts, and one impact event jars the spacecraft off of its axis, coming dangerously close to breaking Giotto’s radio contact with Earth and forcing the vehicle to stabilize itself with thrusters. After its encounter with the comet, Giotto falls into a long, looping orbit around Earth, where it will be reactivated to study another comet years later.
