Space Exploration Vocabulary: Key Terms Defined

Space Exploration Vocabulary

Satellite: An artificial body placed in orbit around the Earth, Moon, or another planet to collect information or for communication.

Man-made: Caused by human beings.

Atmosphere: The envelope of gases surrounding the Earth or another planet.

Gravity: The force that attracts a body towards the center of the Earth or towards any other physical body having mass.

Space Capsule: A small spacecraft or the part of a larger one that contains the instruments or crew.

Cosmonaut: An astronaut of the Soviet or Russian space program.

Orbit (verb): To move in orbit around a star or planet.

Re-enter: To go back to a place where you were earlier or to an activity that you did or were doing earlier.

Spacecraft: A vehicle used for traveling in space.

Touchdown: To reach the ground.

Mission: An important assignment given to a person or group of people, typically involving travel abroad.

Space Shuttle: A rocket-launched spacecraft able to land like an unpowered aircraft, used to make repeated journeys between the Earth and space.

Launch (verb): To start or set in motion.

Space Station: A large artificial satellite used as a long-term base for manned operations in space.

Orbit (noun): The curved path of a celestial object or spacecraft around a star, planet, or moon, especially a periodic elliptical revolution.

Astronomer: An expert in or student of astronomy.

Cosmos: The universe considered as a system with an order and pattern.

Telescope: A cylinder-shaped device for making objects that are far away look closer and larger, using a combination of lenses, or lenses and curved mirrors.

Planet: An extremely large, round mass of rock and metal, such as Earth, or of gas, such as Jupiter, that moves in a circular path around the sun or another star.

Crew: A group of people who work together, especially all those who work on and operate a ship, aircraft, etc.

Mission Control: The place on Earth from which a journey into space is controlled.

Black Hole: An object whose gravity is so strong that not even light can escape from it.

Red Giant: A very old, large star with a low surface temperature.

Universe: Everything that exists, including the Earth, planets, stars, and galaxies.

Shooting Star: A meteor seen from the Earth.

Eclipse: The blocking of sunlight from the Earth by the moon.

Milky Way: The galaxy that our solar system is part of.

Light Year: The distance that light travels in one year, about ten trillion km.

Meteor: A piece of rock or other matter from space that produces a bright light as it travels through the atmosphere.

Solar System: The sun and the group of planets that move around it.

Constellation: Any of the groups of stars in the sky that seem from Earth to form a pattern and have been given names.

Crater: The round hole at the top of a volcano, or a hole in the ground similar to this.

Comet: An object that moves around the sun, usually at a great distance from it, that is seen on rare occasions from the Earth as a bright line in the sky.

Supernova: A star that has exploded, strongly increasing its brightness for a few months.

Asteroid: One of many large rocks that circle the sun.

Galaxy: One of the independent groups of stars in the universe.