Beginning on Friday, Dec. 8 we can finally state with absolute certainty that Halley's Comet is coming.
This most famous of all comets travels around the sun in a flattened elliptical orbit that brings it near to the sun and then takes it far out to beyond the outer limits of the solar system. Ever since Feb. 9, 1986, when it arrived at perihelion — the comet's closest approach to the sun — it then began its long journey back out into distant space. And from that time up until the present, the comet has been moving inexorably away from the sun.
