Halley’s Comet

Halley’s Comet is one of the most famous comets known to humanity. While there’s no real reason for its popularity, it’s still an interesting space object to be observed. It was first observed in 239 B.C. in China and notably found by Edmond Halley who examined three sightings in 1531,1607, and 1682. He stated that these sightings were all the same comet and that it would come again in 1758. ( Source)

Image from Britannica

The comets orbit is highly elliptical with an eccentricity of .967 and a period of 75 years. At the perihelion, or closest distance to the sun, its distance is .6 AU which is between the orbits of Mercury and Venus. The aphelion, or farthest distance from the sun, is 35 AU, around the orbit of Pluto. Halley’s orbit it also in retrograde, so it orbits the opposite direction that the Earth is spinning. This orbit suggests that the comet was originally a long-period comet which originated in the Oort Cloud. The gravity of the giant planets acted on the comet which guided it into the inner solar system. (Source)


  1. kierannaughton5896 · April 8, 2019

    Halley’s comet is one of the most popular and well- known comets there is. The information you provided is very informative about its characteristics, but are there any prominent features that make it special? Why did this comet become so famous, when there are so many others out in orbit, as well?


  2. Campbell Flower · April 8, 2019

    Thank you for an interesting post on something I’ve been curious about for a while. One thing I’m wondering is why is “Halley’s Comet” such a household name, meaning why have we all heard of it and associate some sort of significance? I am surprised to read it is just a regular comet. What I also find most interesting about your post is that this comet’s distance from the sun varies so greatly. Normally we expect bodies to orbit in our solar system with a slightly elliptical orbit, but the eccentricity of Halley’s comet is so great that it does make it a more fascinating object to study. I am also wondering when is the next time we will see it orbit?


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