space 1
The path one object takes around another object in space, like Earth's nearly circular path around the sun.
Orbit
A small piece of rock or metal in space that can become a meteor when it enters Earth’s atmosphere.
meteoroid
A spacecraft that travels far into space to collect data, but does not have people on board.
probe
The movement of one object around another, such as Earth’s revolution around the sun, which takes one year.
Revolution
A measure of how hot or cold something is, influenced by a planet’s distance from the sun.
temperature
The force that pulls objects toward one another, such as the force keeping planets in orbit around the sun.
gravity
A ball of ice, dust, and gas that orbits the sun, often forming a glowing tail as it gets closer.
comet
The four planets closest to the sun (Mercury, Venus, Earth, and Mars), which are mostly rocky.
inner planets
The spinning of a planet or moon on its axis, like Earth’s daily rotation, which causes day and night.
rotation
What something is made of, such as the gases that make up a star or the rocks that form a planet.
Composition
A large object in space that orbits a star, such as Earth or Jupiter.
planet
A small celestial body that orbits the sun, like Pluto, but does not clear its orbital path of other debris.
The four planets farthest from the sun (Jupiter, Saturn, Uranus, and Neptune), which are mostly made of gas.
outer planets
A period of the year marked by specific weather patterns, caused by Earth's tilt as it orbits the sun.
season
An oval-shaped path, like the one Earth follows in its orbit around the sun.
Ellipse
The collection of planets, moons, and other objects that orbit the sun.
solar system
A tool used by astronomers to look at distant objects in space.
telescope
A giant ball of gas that produces light and heat, such as the sun.
star
The slant of Earth’s axis, which causes different parts of Earth to receive varying amounts of sunlight, creating seasons.
tilt
The distance that light travels in one year, used to measure the vast distances between stars.
Light Year
A small, rocky object that orbits the sun, mostly found in the asteroid belt between Mars and Jupiter.
asteroid
An object, natural or man-made, that orbits a planet, such as Earth's moon or the Hubble Space Telescope.
satellite
The star at the center of our solar system that provides light and energy for Earth.
Sun
The time it takes for a planet to complete one full orbit around the sun, such as Earth’s year of 365 days.
year
The angle of the sun above the horizon, which affects how much direct sunlight Earth receives.
altitude