Space Words That Start with O

There are so many astronomical objects out there behaving in mysterious ways that astronomers are still trying to figure out. A brand new set of words and language has to be invented every time something is discovered and that is part of what makes the study of space so interesting. There’s so much out there that is waiting to be found.

The use of mythological and ancient names to name all the objects that are in space has also always given astronomy an air of mystery and wonder that attracts all kinds of people and incentivizes them to look at the sky every night.

There are so many space-related words and terms that it is hard to keep up.

This is why below, we have compiled a list of space words that start with O so you can learn more about the study of the universe. These are words that are related to astronomy and space, if what you are looking for is specifically for name ideas or the names of objects, check out our lists of star names, planets, or constellations. You will also find those sorted by letter.

O-type StarA massive and extremely hot star of spectral type O.
OberonOne of the major moons of Uranus, discovered by William Herschel in 1787.
OblatenessThe flattening of a celestial body at its poles due to its rotation.
ObservatoryA facility equipped for observing celestial objects and phenomena.
Occam’s RazorThe principle that, among competing explanations, the simpler one is usually preferable.
Occulting DiskA device used in telescopes to block out the light of a bright object to observe a fainter one.
Omega CentauriA globular cluster in the Centaurus constellation, one of the brightest and largest known.
Omega NebulaA large emission nebula in the Sagittarius constellation.
Oort CloudA theoretical region of icy bodies at the edge of the solar system.
Open ClusterA group of relatively young stars that formed from the same molecular cloud.
OphiuchusA constellation located near the celestial equator, often depicted as a serpent-bearer.
OrbitThe path that a celestial body takes around another due to gravitational forces.
Orbit InsertionThe process of placing a spacecraft into its intended orbit around a celestial body.
Orbital VelocityThe minimum velocity needed for an object to maintain a stable orbit around a planet or star.
OrionA prominent winter constellation, named after the hunter from Greek mythology.
Orion NebulaA diffuse nebula in the Orion constellation, a region of active star formation.
OsirisAn asteroid in the outer asteroid belt, named after the Egyptian god of the afterlife.
OumuamuaAn interstellar object that passed through the solar system, believed to be an elongated asteroid or comet.
Outer GalaxyThe region of a galaxy located away from the galactic center, typically containing spiral arms.
Outer PlanetsThe gas giant planets (Jupiter, Saturn, Uranus, Neptune) located beyond the asteroid belt.
Outer SpaceThe vast expanse beyond Earth’s atmosphere containing stars, planets, and other celestial objects.
Owl ClusterA nickname for Messier 103, an open cluster of stars in the Cassiopeia constellation.
Owl NebulaA planetary nebula in the constellation Ursa Major, known for its resemblance to an owl’s face.
Ozone LayerA layer of ozone high in Earth’s atmosphere that absorbs most of the Sun’s ultraviolet radiation.
space words that start with the letter O

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