Words in This Story solar system – n. a star and the planets that move around it light-year(s) – n. a unit of distance equal to the distance that light travels in one year (about 5.88 trillion miles or 9.46 trillion kilometers dwarf planet – n. an object in space that looks like a small planet but lacks special qualities that are required for it to be defined as such data – n. facts or information used usually to calculate, analyze, or plan something exciting – adj. causing feelings of interest and enthusiasm concept – n. an idea of what something is or how it works neural network(s) – n. a computer system designed to be similar to the human brain and nervous system exoplanet(s) – n. a planet that is beyond our solar system