The wind was sharper this close to the water. Hands trembling, Astrid hurried to zip her jacket before the ride operator checked her seatbelt. She wished her tremors had more to do with the chill in ... [+]
The last apparition of Halley's Comet was in 1986, approaching Earth as close as 0.4 astronomical units. Halley takes a long journey to visit us. The comet follows an elliptical orbit that reaches past Pluto before returning to the inner solar system. Its next flyby will be 76 years later, in 2061. During its orbit, Halley leaves fragments of itself in its trail—stray rocks, dust, and sometimes ice, blown away by the solar winds, floating in clumps across space. Occasionally, the Earth passes through this debris, causing it to rocket toward the planet at high speeds, burning brightly as it di
