Astronomy Vocabulary

Vocabulary flashcards covering key astronomical concepts, celestial mechanics, lunar phases, solar system components, and gravitational forces based on the lecture transcript.

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 $90\text{-degree}$ 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 $90\text{-degree}$ 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