Matching Pairs Galaxy Universe Review Online version Galaxy, Universe, Components of Universe Review by Andrea Soliz 1 light year 2 Irregular Galaxy 3 blue shift 4 Galaxy 5 Spiral Galaxy 6 Big Bang Theory 7 red shift 8 Nebula 9 Elliptical Galaxy 10 star the distance a single beam of light travels in one year. The unit of measurement used to measure the distance of objects in outer space. a hot ball of gas that burn elements like hydrogen and helium through the process of nuclear fusion. The theory that our universe, which was once a small, dense ball of energy, exploded and expanded to create the universe we know today. cloud of gas and dust in space that forms stars or is formed by the death of a star. A system of billions of stars with dust and gas. the concept that an object is moving further away the concept that an object is moving closer and closer.