Why halleys comet famous

This Day In History. History Vault. Recommended for you. Brandenburg Gate: A Brief History. A Brief History of Bloodletting. A Brief History of Chopsticks. Nov 9, , am EST. Edit Story. Feb 9, , pm EST. I inspire people to go stargazing, watch the Moon, enjoy the night sky. Follow me on Twitter or LinkedIn. Check out my website or some of my other work here. However, it differs from most periodic comets by taking a much longer, more leisurely route around the Sun. The comet travels in the opposite retrograde direction to the planets along a huge elliptical orbit which carries it beyond the orbit of Neptune.

One circuit of the Sun takes 76 years to complete. It is so bright that it has been seen and recorded for thousands of years - since at least BC. For example, the apparition is shown in the famous Bayeux Tapestry which records the Norman invasion of England, while the return inspired Florentine artist Giotto di Bondone to include it in his painting of the Wise Men visiting the infant Jesus.

Comet Halley was most recently visible in The ESA spacecraft Giotto was one of an international armada of spacecraft dispatched to study the comet at that time. This corresponds to an orbital circumference around the Sun of about 7. The period varies from appearance to appearance because of the gravitational effects of the planets. Measured from one perihelion passage to the next, Halley's period has been as short as The comet's closest approach to Earth occurred in , at a distance of 0.

At that time, April 10, , Halley reached a total apparent brightness of about magnitude The light of Halley was spread over an extended area, however, so its surface brightness was less than that of Venus. During its appearance, Halley's nearest approach to Earth occured on the outbound leg of the trip at a distance of 0.

It was slightly brighter than the north star Polaris, but again spread over a much larger area than a point-like star. At aphelion in , Halley was The comet was moving 0. At perihelion on February 9, , Halley was only 0. Halley was moving at , mph With each orbit around the Sun, a comet the size of Halley loses an estimated 3 to 10 feet 1 to 3 meters of material from the surface of its nucleus.

Thus, as a comet ages, it eventually dims in appearance and may lose all the ices in its nucleus. The tails disappear at that stage, and the comet finally evolves into a dark mass of rocky material or perhaps dissipates into dust.