16 Facts About Halley's Comet
Space and Astrology 7/29/09
By: Yona Williams
During the 20th century, Halley's Comet made two appearances Ã¢â‚¬â€œ one in 1910 and one in 1986. In this article, you will learn what significant event took place on the last time the comet become visible within the inner Solar System and many other interesting facts about the most famous comet in the world.
1. Halley's Comet is also referred to as 1P. The 'P' stands for 'periodic,' while the '1' refers to being the first periodic comet to be identified.
2. The orbital period of Halley is approximately 75 years (75.32 years to be exact).
3. The orbit of the comet is described as 'retrograde,' meaning that it travels opposite the direction of planetary orbits.
4. Halley's Comet is estimated to be 4.5 billion years old.
5. The shape of the comet is typically described as looking like a peanut.
6. Halley is respected as a large and active comet with well-defined characteristics. However, when studying the comet, it is important to note that it does not present a general representation of all comets.
7. The comet is estimated to measure between seven and 10 kilometers wide with a length of 15 kilometers.
8. What is Halley's Comet made out of? Its composition is comprised of water, hydrocarbons, iron, carbon monoxide, methane, ammonia, and sodium.
9. Ignorance and fear of the unknown entities found in the sky and space, Turkish forces that were laying siege to Belgrade described Halley as an apparition to be feared. The tail was compared to the tail of a dragon. Records state that they viewed the tail as a "long sword advancing from the west."
10. The first up-close observation of the comet took place on March 4, 1986 when the Soviet Vega 1 probe started sending back images of Halley.
11. When it comes to predicting the dates when Halley's Comet will make a return, it's not an easy task to accomplish. For instance, gravity linked to other celestial bodies in the Solar System can affect the orbit.
12. Halley does not always display a 76-year orbit. Over time, the orbital period of the comet has ranged from 76 years to 79.3 years.
13. When pronouncing the name of the comet, the majority of people are saying it wrong. It is a habit to pronounce the comet as 'Halley' in such the way that it rhymes with 'valley,' but the proper pronunciation is the way in which Edmond Halley said his name Ã¢â‚¬â€œ 'Hawley' Ã¢â‚¬â€œ which rhymes with 'wally.'
14. Halley was unable to see his prediction come true. 16 years later, Halley appeared again, just as he had stated. Later, the comet was named in his honor.
15. During its most recent appearance of Halley's Comet (1986), five spacecraft hailing from the USSR, Japan, and the European Community climbed into space to catch sight of the comet. The most fruitful efforts were captured by Europe's Giotto probe. This was the closest that any probe had ever gotten to Halley (the probe a product of the European Space Agency). Giotto launched into flight in July of 1985 and on March 13, 1986, came as close as 370 miles from the comet.
16. The next scheduled return of Halley's Comet to the inner Solar System is in the year 2061.