He is always writing about journey to other planets.
The planets revolve around the sun.
I can't imagine life on another planet.
This chapter will focus on the riddles of the planets.
The earth is a beautiful planet.
Astronomy deals with the stars and planets.
Planets move around a fixed star.
The earth is one of the planets.
The smaller planets hovering around the planet Jupiter reminded him of the guards surrounding a king when he walked outdoors, and Kepler called them satellites.
Is there intelligent life on other planets?
Mars resembles our planet in some ways.
The sun has nine planets.
They sent some people to live on the planet.
The earth is one of the sun's planets.
The earth is not a star, but a planet.
The surface of a planet is composed mostly of water.
What would you do if you saw a man from another planet?