After discussing how classifications of comets can differ depending on the solar system that it orbits and the length of time taken to orbit, it seemed fun to discuss the most famous comets that everyone would know about. It is worth noting that this list is what we think are the 6 most famous comets, and this list can change depending on who is asked, where they live, and how old they are. The reason for this being is that older astronomers have had the opportunity to see these comets during their lifetime during their recent encounters with the Earth and the Solar System.
1. Halley’s Comet
Halley’s Comet, otherwise known as Comet Halley is a short-period comet visible from Earth every 75–76 years. Halley’s Comet is the only known short-period comet that is regularly visible to the naked eye from Earth, and the only naked-eye comet that might appear twice in a human lifetime. The first observations and recordings of the comet was in 240 BC, with the most recent sighting in the inner parts of the Solar System in 1986. The next time that that the comet will appear visible to those on Earth will be in mid-2061 to 2062. During its 1986 apparition, Halley’s Comet became the first comet to be observed in detail by spacecraft, providing the first observational data on the structure of a comet nucleus and the mechanism of coma and tail formation. Haley’s Comet is famous for being visible to most by the naked eye during its approach and its short orbital period.Its officially designation is 1P/Halley.
The Comet Hale-Bopp is perhaps the most widely observed of the 20th century and one of the brightest seen for many decades. The comet was named Hale-Bopp for both its discoverers, Alan Hale and Thomas Bopp discovered Comet Hale–Bopp separately on July 23, 1995 before it became visible to the naked eye. Both Hale and Bopp were amateurs who were looking at the nights sky and realized they had discovered an unknown object and notified the astronomical bodies of the discovery. It is possible that the previous perihelion may have been observed in ancient Egypt during the 6th dynasty reign of the Pharaoh Pepi II. When Hale Bopp came into the solar system in 1997, the comet’s orbit was shortened considerably by Jupiter’s gravity to a period of roughly 2,533 years, and it will next return to the inner Solar System around the year 4385. It is worth noting that the comet’s current orbit is almost perpendicular to the plane of the ecliptic, which will not only explain the effect that Jupiter would have on the comet, but also why the comet might not come closer to the Earth in the future. Other designations for the comet include The Great Comet of 1997, and C/1995 O1. It is worth noting that there is a tragic side to the story of Hale-Bopp, as about 40 people from the “Heaven’s Gate” cult committed mass suicide as the comet approached Earth.
Comet Tempel-Tuttel is a periodic comet with an orbital period of 33 years and is most famous for being the parent body of the Leonid meteor shower. In 1699, the comet was observed by Gottfried Kirch but was not recognized as a periodic comet until the discoveries by Tempel and Tuttle during the 1866 perihelion. The orbit of 55P/Tempel–Tuttle intersects that of Earth nearly exactly, hence streams of material ejected from the comet during perihelion passes do not have to spread out over time to encounter Earth. As the comet debree lacks the time to spread out when encountering Earth, the result is the 33-year cycle of Leonid meteor storms. November 2009 was the last time this meteor storm occurred, so the next occurrence will be around 2042.
4. Swift Tuttle
With a 133 year orbital period around the sun, the comet Swift-Tuttle last reached perihelion in 1992 and will return in 2125. The comet is quiet large being 16 miles across and is the source of the Perseids Meteor Shower, which takes place each August. The Perseids is a result of dust emitted by Swift-Tuttle when it orbits around the sun.
5. Shoemaker Levy-9
Being most famous for breaking up and providing the first direct observation of an extraterrestrial collision of Solar System objects, Shoemaker Levy 9 was able to provide a plethora of scientific data about Jupiter and its atmosphere. The comet was discovered by astronomers Carolyn and Eugene M. Shoemaker and David Levy in 1993 orbiting Jupiter through a photograph from a Schmidt telescope from Palomar Observatory. The comet was pulled apart by Jupiter’s gravitational forces and gained worldwide media attention and fame for the impact with Jupiter.
The comet was discovered on 30 January 1996, by Yuji Hyakutake, an amateur astronomer from southern Japan, who was looking for comets using binoculars. The comet is actually the second comet named Hyakutake, and was only discovered because Yuji Hyakutake was looking at where the first comet had been and found this new comet. Hyakutake is a long-period comet, with a 17,000 year orbital period. Several scientific discoveries were made during its observation including X-Ray information, length of the tail, and nucleus size and activity. Of the discoveries made, what was the most surprising to cometary scientists was the first discovery of X-ray emission from a comet. The X-ray emissions are believed to have been caused by ionised solar wind particles interacting with neutral atoms in the coma of the comet. The Ulysses spacecraft unexpectedly crossed the comet’s tail at a distance of more than 500 million kilometers from the nucleus, showing that Hyakutake had the longest tail known for a comet. Radio observations were successful in determining the size and degree being ejected from the comet nucleus.
If you’re curious about the difference between asteroids, comets, and meteors, check out our article on the subject.
Sources And Further Readings