All of space and everything in it

A collection of stars, dust, and gas bound together by gravity

A ball of hot gas, primarily hydrogen and helium, that undergoes nuclear fusion.

A large spiral galaxy that is home to Earth and the rest of our solar system, and about 200 billion stars.

a galaxy whose arms curve outward in a pinwheel pattern

An oval-shaped galaxy that contains mainly older stars, a few new stars, and very little gas and dust.

A galaxy that has an undefined shape; these are thought to be galaxies affected by the gravity of other galaxies

A large cloud of dust and gas in space

sun, planets, and all the other objects that revolve around the sun

a sphere shaped portion of space and matter that can be seen from Earth

process that fuels the stars (2 hydrogen nuclei combine to become helium)

the universe originated in a huge explosion that released all matter and energy

energy transferred through space by waves. (microwaves, gamma rays, visible light, infrared, radio waves)

shift of light to a longer wavelength as an object moves away

force of attraction between objects that is due to their masses.

large body in space that orbits a star and does not produce light of its own

a natural object that orbits a planet

the small rocky planets closest to the Sun: Mercury, Venus, Earth, and Mars

Jupiter, Saturn, Uranus, & Neptune. Called Gas Giants.

the brilliant explosion of a dying star