Astronomy has many creative and strange names for the bizarre and wacky objects in the universe. Learn some new words today.
Some words in astronomy are curious, funky, odd, and downright puzzling. It's the ABCs of unusual astronomical words. Brush up on your space terms with this mini dictionary to find the definitions of some words that are out-of-this-world!
Analemma -- It sounds like it could be a name for a little girl. In reality, it is the figure-eight shape that the Sun traces in the sky if it were to be photographed at the same time every day for a year.
Bok globules -- Small dark clouds of gas and dust named after American astronomer Bart J. Bok. They can be seen especially well in photos of HII regions or against a dense field of background stars. These clouds are star formation regions for lower-mass stars.
Catena -- Another word that sounds like a little girl's name. But it is a chain of craters on a planet or satellite.
Dobsonian -- A telescope invented by John Dobson. This type of telescope is easy for amateurs to construct themselves and less expensive to buy. Its altazimuth mounting allows it to slide easily from one sky object to another.
Encke Division -- A gap in Saturn's A ring.
Faculae -- Bright patches seen on the sun or planetary satellies. This term is usually connected to solar phenomena, however. Faculae occur in the photosphere and are hotter than the surrounding area. They precede sunspots that form in the same area and linger several weeks after the disappearance of the sunspot.
Gegenschein -- A phenomenon that can be seen in very dark sky locations. A faint spot of light appears on the ecliptic at a point that is 180 degrees from the Sun's current position. It is the counterglow of the Sun on dust in space.
Herbig-Haro objects -- The name of this one sounds like the punchline to a joke. HH objects are small bright patches of nebulosity ejected from young stars.
Ishtar Terra -- Highlands of Venus near its north pole, bordered on three sides of by mountains.
Jansky -- A unit of flux density named after Karl Jansky, the discoverer of radio emissions from the Milky Way.
Kuiper belt -- Pronounced KY-per. A disk of comets and other solar system bodies that lies between 30 and 50 AU from the Sun. Pluto lies in the Kuiper belt.
Leptons -- Elementary particles that show no evidence of internal structure. Leptons includes electrons, muons, and neutrinos.
Mensa -- Ask a Mensa member if they know what the word means. A mensa is a flat-topped landform with steep sides on a planet or satellite. It is also a Southern Hemisphere constellation that means "Table Mountain".
Nadir -- The opposite of zenith. A point on the celestial sphere that lies beneath an observer. The point that would be overhead if you were on the opposite side of the Earth.
Oort cloud -- A sphere of comets that lies at the edge of the solar system. The Oort Cloud may contain 1 trillion comets and extend as far as 100,000 AU from the Sun.
Pholus -- A large solar system object that has a highly elliptical orbit ranging from Saturn to Neptune's orbit, or 9 to 32 AU. It was discovered in 1991 and is approximately 200 kilometers in diameter.
Quasar -- Stands for quasi-stellar object. Highly redshifted objects that are bright in optical light and also strong emitters of infrared and x-rays.This pointlike source emits the equivalent light of hundreds of galaxies. They are probably caused by activities around supermassive black holes at the center of extremely distant galaxies.
Roche limit -- Not the number of pests I will put up with but the closest distance a satellite can get to its parent planet before being torn apart by tidal forces. The Roche limit is approximately 2.45 times the radius of the parent body.
Syzygy -- When the Sun, Earth, and Moon or other planet lie in the same line. This occurs when the moon or a planet is at opposition or in conjunction. Say that ten times fast.
Tunguska -- A region in Siberan known for an asteroid that exploded in the atmosphere above this small town in 1908. 80 kilometers of forestland were flattened in the Tunguska event and the explosion could be felt thousands of miles away.
Uhuru -- The first satellite for x-ray astronomy. It gets its Swahili name (Freedom) because it was launched off the coast of Kenya in 1970.
Vulcan -- A hypothetical planet once believed to reside between Mercury and the Sun. Also a race from Star Trek. Spock was half-Vulcan. You will not be tested on this one.
WIMP -- Weakly Interacting Massive Particle - a hypothetical particle that could help to explain dark matter. (Are nerdy scientists partial to WIMPs?)
XMM -- Not the breakup you had with your M&Ms in exchange for healthier living. An x-ray mission that was part of ESA's Horizon 2000 space program. The other three parts of the program were STEP, FIRST, and ROSETTA.
Ylem -- According to the Big Bang Theory, ylem is the original matter that existed before the formation of the chemical elements we know today.
Zwicky catalog -- Collection of galaxies and galaxy clusters published by Fritz Zwicky and others.
