Astronomy Vocabulary

Vocabulary flashcards covering key astronomy concepts, definitions, and planetary facts.

Atmosphere

A mixture of gases that surround a planet or moon.

Celestial Body

An object located in space and observed in Astronomy.

Direct Sunlight

Sunlight that hits the earth at a $90$-degree angle.

Earth

$3\text{rd}$ planet from the sun.

Eclipse

The partial or total blocking of one object in space by another.

Elliptical

An elongated circle, or oval shape.

Gravity

A force of attraction between objects that is due to their masses and distance apart.

Indirect Sunlight

Sunlight that hits earth with less than a $90$-degree angle.

Inner Planets

Mercury, Venus, Earth, Mars.

Lunar Phases

The changing appearances of the Moon as seen from Earth due to the position of the Earth, Sun, and Moon.

Mass

The amount of matter in an object.

Moon

A natural satellite that revolves around a planet.

Orbit

The path that a body follows as it travels around another body in space.

Outer Planets

Jupiter, Saturn, Uranus, Neptune.

Penumbra

The part of a shadow during an eclipse where the light is partially blocked.

Revolution

The movement of an object around another object.

Rotation

The spinning motion of a planet on its axis.

Satellite

Any natural or artificial object that revolves around another object.

Seasons

Caused by the tilt of Earth on its axis as it revolves around the Sun.

Solar Energy

Energy released by the Sun which heats the Earth.

Solar System

A sun and all the planets that orbit around it.

Space

The physical universe beyond the earth's atmosphere.

Sun

A typical star that is the source of light and heat for the planets in the solar system.

Thermal Energy

Heat energy.

Umbra

The darkest part of a shadow during an eclipse.

Universe

Space and all the matter and energy in it.

Waning

Phases of the Moon when the Moon appears to be getting "smaller".

Waxing

Phases of the Moon when the Moon appears to be getting "bigger".

Weight

The force of gravity on an object.