Astronomical Dictionary on Letter #C

Celestial Equator

The projection of the Earth's equator upon the celestial sphere. Right ascension is the longitude me...

Celestial Sphere

The projection of space onto the night sky, an imaginary hollow sphere of infinite radius surroundin...

Celestial Poles

The projection of the Earth's poles onto the celestial sphere. One of two points about which the Cel...

Chromosphere

The layer between the photosphere and the corona in the atmosphere of the Sun, or any other star, ma...

Coma

(1) The luminous structure surrounding the head (solid portion) of a comet. (2) A defect in an opt...

Comet

An icy object in independent orbit about the Sun; smaller than a planet, usually having a highly ell...

Conjunction

When two bodies appear to close together in the sky, i.e. they have the same Right Ascension. Mercur...

Constellation

An arbitrary grouping of stars which form a pattern. The 12 zodiacal constellations, Orion, the Big ...

Corona

The outer layer, and hottest part, of the Sun's atmosphere; also the halo appearing around the black...

Coronagraph

A special telescope which blocks light from the Sun's disc, thus creating an artificial eclipse, in ...

Cosmic Ray

An extremely fast, energetic and relativistic (high speed) charged particle. ...

Cosmos

The Universe: the word is derived from the Greek, meaning 'everything'. ...

Culmination

A general term for the hightest and lowest points a planet or celestial body reaches in the sky rela...

Culmination

A general term for the hightest and lowest points a planet or celestial body reaches in the sky rela...

Cuspate

Shaped like a cusp; a sharp projection of material....

Crust

The outermost layer of the lithosphere....

Crater

An approximately circular depression, sometimes surrounded by a raised rim. Craters are typically fo...

Chondrite

A stony meteorite, composed of finely crystallized material....

Chasma

A large canyon....

Charon

In Greek mythology, ferryman of the River Styx, who carried the dead to the underworld. Each dead pe...

Cerberus

In Greek mythology, the three-headed dog that guards the entrance to the underworld....

Centaur

In Greek mythology, a being with the head, arms, and torso of a man, and the body and legs of a hors...

Cassini

Gian Domenico Cassini (1625-1712) Astronomer born in Italy, later a naturalized French citizen. Disc...

Carson

Rachel Carson (1907-1964) American biologist and author....

Candor

Candor Chasma - from the Latin candor, meaning "blaze" or "the white" from its appearance....

Callisto

In Greek mythology, a nymph, follower of Artemis. Zeus wanted to woo her, and so disguised himself a...

Caldera

A large volcanic depression at the summit of a volcano, caused by collapse or explosion....