What is an icy rock that lets off gas and dust, which may form tails when it is flying close to a sun.

What is a meteoroid that lands on the surface of a planet.

What is a part of Earth’s atmosphere that absorbs lots of the sun’s ultraviolet radiation. It is made of a gas called ozone, which is a molecule of three oxygen atoms.

What is the curved path that a planet, satellite, or spacecraft moves as it circles around another object.

What is a set that includes a star and all of the matter that orbits it, including planets, moons, asteroids, comets, and other objects.

What is a large body in outer space that circles around the sun or another star.

What is all of space and time, and everything in it. It’s everything ever!

It’s not a year, or an amount of time at all. It’s the distance light travels in one year. It’s the same as 5,878,499,810,000 miles (or 9,460,538,400,000,000 meters). When things are very far away, it’s easier to talk about their distance i

What is a large, bowl-shaped dent in the ground. They can be caused by an explosion or the impact of a meteorite.

What is the gases held by gravity around Earth and around other planets. It can also be used to talk about gases around stars.

What is the star in the center of our solar system.

What is a natural object that travels around a bigger natural object.

What is an object that orbits another object. A moon is actually this. We also say X to refer to spacecraft people build that orbit Earth, other planets, moons, asteroids, or other objects out in space.