IP Halley's Comet Halley's comet, which passes around the Sun every 76 years, has an elliptical orbit. When closest to the Sun (perihelion) it is at a distance of 8.823 x 10^10 m and moves with a speed of 54.6 km/s . The greatest distance between Halley's comet and the Sun (aphelion) is 6.152 x 10^12 m . Calculate its speed at aphelion.