Solar means relating to the sun. A solar panel collects energy from sunlight and converts it into electricity. A solar eclipse happens when the moon passes between Earth and the sun, briefly blocking the sun's light. Solar power refers to energy that comes from the sun.

Our solar system is the collection of planets, moons, and other objects that orbit our sun. Everything in our solar system, from tiny asteroids to giant Jupiter, moves in paths determined by the sun's powerful gravity.

Scientists study solar energy because the sun provides an enormous amount of power. Every hour, enough sunlight reaches Earth to power the entire planet for a year, if we could capture it all. Unlike coal or oil, solar energy doesn't run out and doesn't pollute the air.

You might also hear the word in a solar calendar, which is a calendar based on Earth's orbit around the sun (like the one we use every day), or in solar wind, which describes streams of particles the sun constantly sends out into space.