List of periodic comets facts for kids
Periodic comets are special space objects that orbit the Sun regularly. They are also called short-period comets because they complete one trip around the Sun in less than 200 years. We know them well because we've seen them pass by the Sun more than once. For example, 153P/Ikeya–Zhang is one of these comets.
When a periodic comet is seen passing the Sun for a second time, it usually gets a permanent number. This helps scientists keep track of them. However, some periodic comets don't have a number yet, like P/2005 T5 (Broughton). If a comet isn't seen again after several trips, or if it's thought to have broken apart, it gets a "D" added to its name. For example, 3D/Biela and 5D/Brorsen are comets that were once periodic but are now considered lost.
Most comets are named after the people who discovered them. But sometimes, a comet is named after someone who figured out its path in space, like 2P/Encke or 27P/Crommelin. It can be tricky to predict exactly where a comet will be in the future. This is because planets can pull on them, changing their path slightly. Also, comets release gas and dust, which forms their bright tail and fuzzy head (called a coma). This release of material can also affect their movement. But for numbered periodic comets, scientists can usually predict their next close approach to the Sun (called perihelion) very accurately.
Sometimes, different periodic comets might have similar names, especially if they were discovered by the same group of people. For example, there are many "Shoemaker–Levy" comets or "NEAT" comets. To tell them apart, the International Astronomical Union (IAU) uses a number before the "P" (for periodic). So, 181P and 192P/Shoemaker–Levy are both "Comet Shoemaker–Levy," but their numbers make them unique.
In the world of comet names, letters are used to describe them:
- C means it's a non-periodic comet, meaning it takes a very long time to orbit the Sun, or it might only pass by once.
- P means it's a periodic comet, like the ones we're talking about here.
- D means the comet has been lost or has broken apart.
- X means scientists couldn't figure out a reliable path for the comet, often for very old historical comets.
- I is for an interstellar object, which means it came from outside our solar system.
- A is for an object that was first thought to be a comet but turned out to be a minor planet, or an object that doesn't show comet activity even if its path is very open.
List of Halley-type comets
See also
In Spanish: Anexo:Cometas periódicos para niños
- List of comets by type
- List of numbered comets
- List of near-parabolic comets
External links
- Minor Planet Center Periodic Comet Numbers
- Cometography.com Periodic Comets
- Seiichi Yoshida's Comet Catalog
- MPC: Dates of Last Observation of Comets (periodic and non-periodic)
de:Liste der Kometen#Periodische Kometen lb:Koméitelëschten#Periodesch Koméiten
