A Guide to Basic Astronomical Terminology

Whether you are an avid Star Trek fan or just a fan of the skies, it is always a helpful resource to know at least the basics of what you are seeing and or studying.

Altitude – the vertical distance of an object above the skyline

Asteroid – a small mass that orbits around the sun sometimes bringing their orbit across the paths of other planets

Atmosphere – the layer of gases that surround a star, moon, and planet

Aurora borealis –particles from the Sun that are charged and mix with the magnetic field of the Earth creates a colorful glow in the northern and southern hemispheres.

Comet – a large ball of rock and ice that orbit the sun, some actually form a long tail-like trail of gas and dust if the comet orbits close enough to the sun where it becomes heated.

Constellation – imaginary pictures in the sky that are formed by the gathering of stars.

Dark Matter – unseen matter in the universe that can only be detected by its effects on the gravity of other masses

Eclipse – the partial or total blocking of one solar system mass by another

Extragalactic – anything that is beyond our own galaxy

Extraterrestrial – anything that does not come from Earth

Galaxy – a large group of stars

Gravity – two bodies that attract to each other by a physical natural force

Ionosphere – the upper atmosphere of a planet that contains charged particles

Kuiper Belt – large objects of ice that orbit beyond the planet Neptune

Lunar Eclipse – occurs when the moon passes into the Earth’s shadow

Matter – anything that contains mass

Mass – the total amount of material found in an object

Meteor – small rock or dust particles that are burnt up in the Earth’s atmosphere

Meteor Shower – an occurrence when there are a large number of meteors that cross into the Earth’s atmosphere at the same time

Meteorite – a large portion of rock that makes it through the Earth’s atmosphere to the ground

Meteoroid – smaller than an asteroid, a meteoroid is a rock that orbits the sun

Nova – when a star becomes several times brighter before returning to its original brightness

Orbit – the path that objects move through space

Planet – an object in the solar system that is large enough to have its own gravity, but is not large enough to transform its matter into energy

Red Giant – when a star expands greatly due to the star’s fuel running out and the star begins to cool giving it a red glow

Satellite – a natural or manmade object that is put in orbit around a planet

Solar Eclipse – when the Earth passes into the shadow of the moon

Solar Flare – an explosion of hot gas on the Sun

Star – a huge sphere of heated gases that generates and gives off its individual radiation

Supernova – a colossal explosion caused when a star drains its energy and dies

Terrestrial – anything that is from Earth

Zodiac – an invented belt across the sky where the sun, moon and planets can be located