If you asked your teachers, parents or friends to name a comet, then they are very likely to answer with one of the most famous: Halley’s Comet. Astronomers believe that people have seen this well-known object since 240 BC. However, it made its most famous appearance in 1066 AD just before the Battle of Hastings.
What is Halley’s Comet?
Halley’s Comet is the only known comet that we can see with the naked eye from Earth. It is also the only visible comet that may occur twice in a human lifetime. A comet is a celestial object which consists of ice and dust. when a comet nears the Sun, its heat melts some of the ice, which creates a “tail” in the comet. Halley elliptically orbits around the Sun in between the orbits of Mercury and Venus.
Halley’s classified as a short-period comet since its orbit around the Sun lasts only around 200 years. Other comets may have orbits that last thousands of years.
Halley’s Comet is seen from earth approximately every 75 years.
Behind the Name
You might be wondering; why ‘Halley’s Comet’ as a name? Perhaps you have some ideas of what you would have called the comet if you had been living when it was found. The English astronomer Edmond Halley first saw the comet in 1682. Using the laws of gravity discovered by his friend, Sir Isaac Newton, Halley realized that he could predict when the comet would next return. He realized that a similar comet had appeared in 1531 and 1607. He suspected it was the same comet that he had seen and set to work figuring out the next time that the comet would visit the inner Solar System. Halley worked out that the comet would make its appearance every 75 to 76 years and hoped to see it again in 1758.
Sadly, this was not to be as the scientist died in 1742. However, he was correct about the comet’s return. It appeared on Christmas Day, 1758 – just in time for the festivities!
Edmond Halley first predicted the next occurrence of Halley’s Comet in 1682.
Named after Edmond Halley, Halley’s Comet made its last appearance in 1986 – many years before you were born! You might, however, have members of your family that would have been old enough to see it streaking across the sky. If you asked them to describe what the comet looked like, then they are very likely to mention a head and a tail.
Halley’s Comet, is a large lump of ice, dust and gas. When it approaches the Sun, after it’s long journey from outer space, it’s warmed by the Sun. Then it becomes bright, showing off its luminous head and magnificent tail. If you followed the comet on its journey into outer space, you would find that it would get very cold and the comet’s bright head and tail would disappear. That’s because it isn’t being kept nice and toasty by the Sun.
Many people say that Halley’s Comet looks like a dirty snowball or a ‘hairy star,’ but you can decide for yourself when you will have the chance to see it in 2061, when it passes by the Earth.