- the scientific study of the universe.
- Italian astronomer and mathematician who was the first to use a telescope to study the stars.
- a decrease in the wavelength of radiation emitted ppby an aroaching celestial body.
- has a bulge in the center and arms that spiral outwards as the galaxy rotates.
- has an undefined shape and contains lots of young stars, dust, and gas.
- can be in different shapes ranging from round, to flattened, elongated spheres & contains older stars & very little gas & dust
- a bright trail or streak that appears in the sky when a meteoroid is heated by friction with the earth's atmosphere. also called falling star.
- an irregularly shaped rock that orbits the sun, mostly occurring in a band asteroid belt between the orbits of mars & Jupiter
- the galaxy containing the solar system, visible as a broad band of faint light in the night sky
- object that is composed of a mass of ice & dust & has a long luminous tail