This was something that left behind a crater off the coast of Mexico that is 93 miles wide and 12 miles deep. It brought about the end of the dinosaurs and almost three-quarters of the plant and animal species then living on Earth.

Rocky fragments left over from the formation of the solar system about 4.6 billion years ago. Most of these orbit the sun in a belt between Mars and Jupiter. Scientists think there are probably millions of them, ranging widely in size from hundreds of kilometers across to less than one kilometer (a little more than one-half mile) wide.

A near-Earth object with a relatively large size (it is about 1,100 feet). It is about the size of the Eiffel Tower in Paris, France. It is named after the ancient Egyptian god of chaos.

Cosmic snowballs of frozen gases, rock and dust that orbit the Sun. When frozen, they are the size of a small town. When a it’s orbit brings it close to the Sun, it heats up and spews dust and gases into a giant glowing head larger than most planets. The dust and gases form a tail that stretches away from the Sun for millions of miles. There are likely billions of these orbiting our Sun in the Kuiper Belt and even more distant Oort Cloud.

Space objects that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth’s neighborhood and possibly collide with it.

A hole where a space object smashed into the Earth in the northern Arizona desert of the United States. It is 560 feet deep and 0.737 miles in diameter and it is around 50,000 years old

This is a short-period cosmic snowball that is visible from Earth every 75–76 years. It is the only known short-period one that is regularly visible to the naked eye from Earth, and the only naked-eye comet that can appear twice in a human lifetime. It last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061.