crater – n. a large round hole in the ground made by the explosion of a bomb or by something falling from the sky

meteor – n. a rock from outer space that becomes very hot and burns brightly in the sky as it enters Earth's atmosphere

sediment – n. a solid substance that forms a layer at the bottom of a liquid

megaflood – n. a large, catastrophic flood

deposit – n. a layer of a substance that has developed from a natural or chemical process

impact – n. ta powerful effect something has on a particular person or situation

roar – v. moving fast and in a powerful way

gigantic – adj. very large

geologic – adj. the study of the rocks and similar substances that make up the Earth's surface

habitable – adj. able to support life