Unit 1: Space and Earth Science Terms

Comet

• Chunks of ice and dust that travel through space and revolve around the sun in long, elliptical orbits.

• A type of star that emits light and heat through nuclear fusion.

• A planet that is primarily composed of gas and has no solid surface.

• A large rock or metal object that orbits the sun in a circular path.

Hydrosphere

• All the water on Earth including oceans, lakes, and streams.

• The layer of gases surrounding the Earth.

• The solid outer part of the Earth, consisting of the crust and upper mantle.

• The region of the Earth where living organisms exist.

Asteroid

• A small icy object that orbits the sun; located in the outer solar system.

• A small rocky object that orbits the sun; located in a band between the orbits of Mars and Jupiter.

• A large gas giant planet that orbits the sun; known for its rings.

• A celestial body that emits light and is much larger than a planet.

Rotation

• The movement of a body around another body in space.

• The spin of a body on its axis.

• The change in position of a body over time.

• The process of moving in a circular path.

Revolution

• The motion of a body that travels around another body in space, one complete trip along an orbit.

• A sudden and radical change in political power or organizational structures.

• The act of rotating around an axis or center point.

• A gradual change in the position of a body over time.

Inertia

• An object at rest or in motion tends to remain in its state of rest or in motion.

• An object will always come to a stop unless acted upon by a force.

• An object in motion will accelerate indefinitely without any external force.

• An object will change its state of motion only when a force is applied.

Galaxy

• A collection of stars, dust, and gas bound together by gravity.

• A large body of water surrounded by land.

• A type of celestial event involving a supernova.

• A small group of planets orbiting a star.

Atmosphere

• The layer of gas (like air) that surrounds the planet.

• A solid layer of minerals beneath the Earth's surface.

• The liquid layer of water covering most of the Earth's surface.

• A type of weather phenomenon that occurs in the sky.

Solar System

• The sun and all of the planets and other bodies that travel around it.

• A collection of stars in a galaxy.

• A group of moons orbiting a planet.

• The region of space beyond the Earth's atmosphere.

Geosphere

• All the solid parts of Earth like rocks, mountains, and land.

• The layer of gases surrounding Earth.

• The liquid water found on Earth’s surface.

• The biological components of Earth, including plants and animals.