The heliocentric theory is the idea that the sun, not the earth, is the center of the universe.

He believes in the geocentric theory.

When the sun rises, a new day begins.

He is the center of the team.

The Solar System is composed of eight planets, including Earth.

We installed solar batteries on the roof of our house.

Solar wind affects the Earth's magnetic field.

He was reading a book about the ancient Egyptian sun god.

A solar day is the time it takes for the Earth to orbit around the Sun.

The ocean currents can change due to the effect of the solar tide.