10 Examples of Comets

A Kite It is a space object made up mainly of rocks, ice and dust, which move in different types of orbits (elliptical, parabolic or hyperbolic) around the Sun and which, despite the sporadic or prolonged nature of these routes, are part of the asteroids, planets and their satellites, of our Solar System. For instance: Halley’s comet, Shoemaker-Levy 9, 3D / Connecting rod.

Something characteristic of comets is their visible tail, a kind of wake that constitutes the gases that, when the comet approaches the sun, are produced by the heating of its surface and the sublimation of its materials.

Comets are thought to come primarily from two groupings of spatial objects: the “Oort Cloud”, located between 50 thousand and 100 thousand Astronomical Units far from the Sun, or the “Kuiper Belt”, beyond the orbit of the planet Neptune. Both are residual accumulations of the formation of the Solar System.

Comets have been observed by humanity since ancient times, which has regarded them as messengers or signs of change or advent. According to some theories, the famous Belen star that would have guided the Three Wise Men until the birth of the child Jesus Christ would be none other than Halley’s Comet.

Kites of kites

There are three main ways of classifying comets: according to their orbit, according to their size and according to their age.

  • Comets according to their orbit. A distinction is made between two types of comet according to the spatial trajectory they trace: those with a long period, which come from further afield and are born in the Oort Cloud; and those of short period, that come from the Belt of Kuiper.
  • Kites according to their size. Considering the size of these celestial objects, they can be dwarf comets (0 to 1.5 km), small comets (1.5 to 3 km), medium comets (3 to 6 km), large comets (6 to 10 km), giant kites (10 to 50 km) or Goliath kites (more than 50 km).
  • Kites according to their age. By analyzing the light curves detected in comets, astronomers can calculate the number of orbits they have taken around the sun and classify them into: baby comets (<5), young comets (<30), medium comets (<70), comets old (< 100) y cometas Matusalenes (> 100).

Comet names

Astronomers have designed a specific nomenclature for comets, using the letters P (Periodic) for those with recurrent orbit and C or D for non-recurring ones. This distinction is based on the frequency of appearance of the comet: if its orbit is less than 200 Earth years, they are considered periodic.

Examples of comets

Comet Halley - examples of comets

  1. Halley comet. Probably the most famous comet in existence, it has an orbital period of around 79 years and is one of the brightest and best known of those that come from the Oort Cloud. It is, in fact, the only short-period comet visible to the naked eye from Earth. It has been observed since ancient times and its appearance marked the beginning or end of ages, the advent of saviors or the fall of Empires, according to the particular interpretation.
  2. The Great Comet of 1577. Officially named C / 1577 V1, this comet passed close to Earth in 1577 and was seen by many European astronomers, such as the Danish Tycho Brahe. This event inspired him with the necessary ideas to conclude that there are objects flying above the earth’s atmosphere.
  3. The Great Comet of 1811. This comet, officially named C / 1811 F1, could be seen for 260 continuous days and with the naked eye, given its spectacular nature and its size of 40 km in diameter. Its orbital period is estimated to be 3065 years, so we will not see it in these parts again for a long time.
  4. 19P / Borrelly. This is the name of a periodic comet discovered by Alphonse Borrelly in 1904 and whose orbital period is 6.8 years. In 2001 it was visited by the Deep Space 1 space probe, which was able to take photographs and numerous valuable scientific data.
  5. Comet Coggia. Its official name is C / 1874 H1 and it is a non-periodic comet first observed in 1874 by the French astronomer Jérôme Eugène Coggia. This comet returned to haunt the Earth in 1877 and 1882, the year in which it fragmented and disintegrated in space.
  6. Comet Hale-Bopp. Also known as The Great Comet of 1997 or C / 1995 O1, it is probably one of the most observed comets of the 20th century and one of the brightest ever seen. It was discovered simultaneously by Alan Hale and Thomas Bopp in 1995 and caused a real world stir, when it was claimed that an alien spacecraft was following closely behind. Followers of the Heaven’s Gate UFO religion in the US then committed a notorious mass suicide.
  7. 67P / Churyumov-Gerasimenko. Discovered in 1969 by the Ukrainian scientist Klim Ivanovich Churyumov thanks to the studies of scientist Svetlana Guerasimenko, it has an orbital period of 6.6 years and was, in March 2004, the destination of the European space mission Rosetta. This space probe was able to get close enough to the comet’s irregular body to take pictures of it and measure its magnetic field. The results were key in dismantling hitherto accepted theories about the origin of water on Earth.
  8. 3D / Connecting rod. Sighted in 1772 and 1805, it was not until 1826 that the German astronomer Wilhelm von Biela was able to calculate its orbit. Although its passage through Earth’s orbit was shocking for many populations who saw an apocalyptic announcement in it, in 1845 it was seen fragmented in two and in 1877, when it was supposed to pass again, it did not. Instead, a shower of stars lasting almost 6 hours was seen in the constellation Andromeda. It is presumed to have disintegrated.
  9. Shoemaker-Levy 9. This comet, discovered in 1993 and formally called D / 1993 F2, was very important in the year of 1994, when it hurtled towards Jupiter and crashed inside. The event aroused deep interest in the media and world astronomy, as it was the first observable impact of a cosmic body in the atmosphere of a planet.
  10. 9P / Tempel 1. Periodic comet discovered in 1867 by the German astronomer Wilhelm Tempel, whose orbital trajectory was modified by Jupiter’s gravity in 1881, altering its natural rate of appearance and leading many observers of the cosmos to presume its extinction. However around the 1960s it was rediscovered and in 2005 studied by NASA’s Deep Impact space probe, which fired a projectile at the comet to study its nucleus. It is not a bright comet, its surface is 14 x 4 kilometers and its rotation of 2 Earth days.