It’s no use searching the skies for Halley’s Comet – it won’t appear for another 39 years! But you CAN search out these facts about this famous astronomical mystery -- Tidbits has done the work for you!
• Comets are made up of water, ice, dust, and carbon dioxide. They have long luminous tails that are produced by vaporization when they passes by the Sun.
• The first recorded observation of Halley’s Comet was in 239 B.C., documented by Chinese astronomers. Some studies indicate that the comet may have been observed as early as 466 B.C. by the ancient Greeks.
• English astronomer, geophysicist, mathematician, and physicist Edmond Halley published his first paper in 1676 at age 20, a publication with the rather elaborate title of “A Direct and Geometrical Method of Finding the Aphelia, Eccentricities, and Proportions of the Primary Planets, without Supposing Equality in Angular Motion,” a dissertation about planetary orbits. Halley studied laws of gravity and calculated orbital elements of comets and planets before releasing his 1705 “Synopsis of the Astronomy of Comets,” in which he cited his belief that comets that had appeared in 1456, 1531, 1607, and 1682 were all the same comet, which returned approximately every 76 years
• Edmond Halley estimated the next appearance of the comet to be the year 1758, which did in fact occur that year on Christmas Day. Unfortunately, Halley had died in 1742 and failed to see his prediction come true. In 1759, the year after the comet’s appearance, it was named after Halley. Its official designation is 1P/Halley.
• Halley’s Comet was the first comet to be recognized as periodic, or short-period, one with an orbit of less than 200 years, as opposed to long-period comets, whose orbits last for thousands of years. It’s the only known short-period comet that is visible with the naked eye, without any optical aid, as well as the only naked-eye comet that can appear twice in a human lifetime. Halley’s most recent appearance was in 1986, predicted to appear next in 2061, an orbit of 76 years.
• The small rocky nucleus of Halley, which contains 99% of the comet’s mass, is just 9.94 miles (16 km) across, but its tail, made of up gas and dust, can be up to 62,137 miles (100,000 km) long.
• The first photograph of Halley’s Comet was taken during 1910, when it flew within 13.9 million miles (2.4 million km) of Earth.
• Author Mark Twain was born two weeks after the comet reached its point closest to the Sun in 1835. In his 1909 autobiography, Twain wrote, “I came in with Halley’s Comet in 1835. It is coming again next year, I expect to go out with it…The Almighty has said, “…they came in together, they must go out together.” Twain died on April 21, 1910, just one day after Halley’s Comet appeared.
• So how is Halley’s Comet pronounced? Some say it rhymes with “valley,” while others claim it rhymes with “daily.” Edmond Halley’s biographer, Colin Ronan, prefers to rhyme it with “crawly.” There were several variations in the spelling of his name during his lifetime, including Haley, Hailey, Halley, Hawley, and Hawly. The most common pronunciation rhymes with “valley.”