scientists who study the stars and other objects in the sky
Big Bang theory
states that about 13.7 billion years ago, the universe began with a huge, fiery explosion.
all objects seen in the sky (the Sun, Moon, stars, and planets)
Cosmological red shift
the displacement of spectral lines to redder colors caused by the expansion of the universe
radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge
A galaxy shaped like a round or flattened ball, generally containing only old stars.
a galaxy that does not have a regular shape
a large cloud of dust and gas that can break apart into smaller pieces and form stars
a shift in the spectra of distant galaxies toward longer wavelengths
an insrument with a prism used to find out the elements of a star
a galaxy having a spiral structure
a group of hundreds or thousands traveling together in space