a layer of gases surrounding a planet, star, or moon

the center of an object

a nearly round object that orbits a star, is smaller that a planet, and is not a satellite of another object

a substance with no fixed volume or shape that can expand freely

the force that pulls all objects toward each other

the lightest chemical element; often a gas

an area of our solar system beyond the orbit of Neptune where a group of minor planets and other objects orbit the Sun

the measure of the amount of matter in an object

The smallest planet in our solar system and the closest to the Sun; a terrestrial planet

a solid object that travels around a planet; a natural satellite

a large blue planet that is eighth from the Sun; a gas giant

to revolve around another object

a very large object that orbits a star

a single journey along an orbital path

a natural or human-made object that orbits Earth or another object in space

a group of objects in space that orbit a star

the bright, vaporized part of a comet that points away from the Sun

a large blue-green planet that is seventh from the Sun, a gas giant

the area in space between Mars and Jupiter where most asteroids orbit together

a space object made of ice and dust that orbits a star and develops a long, bright tail as it nears its star

a hole in the ground caused by the impact of an object from space

the third planet from Sun; the planet we live on

a large planet that is mainly made up of gases

the second lightest chemical element; often a gas (this makes balloons float in air)

the largest planet in our solar system and the fifth from the Sun; a gas giant

a small reddish planet that is fourth from Sun; a terrestrial planet

anything that takes up space and has weight

a colorless, odorless, flammable gas commonly called " natural gas"

Earth's only natural satellite

the center of a comet made of small particles of ice and frozen gas that can turn to vapor and form a tail as the comet nears a star

a gas that has no color, taste, or smell and which people need to live

a dwarf planet that was discovered in 1930 and that was once considered a planet

a single turn of something around an axis or a fixed point; spinning

a planet with large rings around it that is sixth from the Sun; a gas giant

a body in outer space, made of hot gases, that shines in the night sky

like Earth; describes planets that are rocky and Earthlike in size

a small planet that is second from the Sun; a terrestrial planet