Astronomical Glossary
Terms every aspiring astronomer should be acquainted with
Meteor Shower
A meteor shower occurs when the Earth passes through the trail of debris left by a comet or asteroid. Meteors are bits of rocks and ice ejected from comets as they move in their orbits about the sun.
Conjunction
Conjunction, in astronomy, an apparent meeting or passing of two or more celestial bodies. The Moon is in conjunction with the Sun at the phase of New Moon, when it moves between the Earth and Sun and the side turned toward the Earth is dark.
Opposition
All the planets in the Solar System orbit around the Sun. At certain points during these orbits, the Earth finds itself directly between the Sun and another planet. When Saturn is in opposition for example, Earth is between the Sun and Saturn.
Phases of the Moon
The phases of the Moon are the different ways the Moon looks from Earth over about a month. As the Moon orbits around the Earth, the half of the Moon that faces the Sun lights up. The different shapes of the lit portion of the Moon that can be seen from Earth are known as phases of the Moon.
Meteor
A meteor is a small body of matter from outer space that enters the earth’s atmosphere, becoming incandescent as a result of friction and appearing as a streak of light.
Meteorite
A meteor that survives its passage through the earth’s atmosphere such that part of it strikes the ground. More than 90 percent of meteorites are of rock, while the remainder consist wholly or partly of iron and nickel.
