Light Year

A unit of distance in astronomy; distance that light travels in one year or about 5.88 trillion miles (9.46 trillion kilometers)

Galaxy• Any of the

very large groups of stars and matter that are found throughout the universe

Big Bang Theory

Theory that states that the universe originated billions of years ago in an explosion from a single point of nearly infinite energy density

Magnitude

• A star’s brightness.

Nebula• A cloud of

dust and gas in space.

Main SequenceContains most of

the stars visible to the naked eye; stars where there is a direct relationship between brightness and size, includes our Sun

H-R Diagram• A chart that

plots the data of stars according to their surface temperature and brightness.

Doppler Effect

• Change in the frequency of a wave due to motion of the source.

Visible Light

• Electromagnetic radiation that can been seen with the unaided eye

Frequency

• The number of complete waves that pass a given point in a certain amount of time

Wavelength

• The distance between the crest of one wave and the crest of the next

Amplitude

• The maximum distance the particles of a medium move away from the rest positions as wave passes through the medium

Electromagnetic Wave

• A transverse wave that transfers electric and magnetic energy

Spring Tide

• Large rise and fall of the tide at or near the full moon.

Neap Tide

• Occurs during first and third quarter moon.

• Little change between high and low tide.