Water is found all over the universe, including on planets, moons, asteroids, and comets. It played a big role in how planets like Venus, Earth, and Mars evolved. The idea of a "habitable zone" where liquid water could exist helps us understand which planets might support life. Recent discoveries show water in unexpected places like Mars, Mercury, the Moon, and even on moons like Enceladus. This is an exciting time for studying water on planets in our solar system and beyond.