The science involved in the observation and explanation of events...
Everything that exists, all matter and energy, including Earth,...
The sun and all of the objects orbiting around it, including planets,...
A small chunk of ice, dust, and rock, that orbits the sun in a long,...
The movement of one object around another
Also called Inner Planets, they are the four planets closest to the...
The time it takes for a planet to spin on its axis
Also called Outer Planets, the four planets which are made of gas, and...
Any of the hundreds of small rocky objects too small to be planets,...
A unit used to measure the distances between the sun and planets1...