The sun is the star at the center of our solar system, a massive ball of burning gases that provides Earth with light and heat. Without the sun, life as we know it couldn't exist. Plants use sunlight to make food through photosynthesis, which feeds nearly every living thing on the planet. The sun's warmth creates our weather patterns, drives ocean currents, and makes Earth habitable instead of a frozen rock.

Ancient civilizations understood how vital the sun was, building monuments to track its movements and creating myths about sun gods. The Aztecs called it Tonatiuh, the Egyptians worshiped Ra, and the Greeks honored Helios. These cultures recognized what science later confirmed: the sun is the engine that powers life on Earth.

The sun is unimaginably large. You could fit about one million Earths inside it. It sits roughly 93 million miles away, yet its light reaches us in just over eight minutes. Scientists estimate the sun is about 4.6 billion years old and will keep shining for another 5 billion years.

When someone tells you to get some sun, they mean go outside and enjoy sunshine. We also use sun as a verb: you might sun yourself at the beach. Something sunny is bright and cheerful, like a sunny personality or a sunny day.