Look up at the day sky. The bright ball you see is the Sun, and it sits at the center of our solar system. As of November 2026, our solar system has eight planets that circle the Sun. Let's visit the eight worlds in order, starting close to the Sun and moving out.

First comes Mercury. It is the smallest planet and the world closest to the Sun. Next is Venus, the second planet from the Sun. Venus is the hottest planet in our solar system. It also spins so slowly that one Venus day, about 243 Earth days, is longer than a Venus year.

Earth is the third planet from the Sun, and it is our home. About 71 percent of Earth is covered by water. Earth's axis is tilted by about 23 degrees from the plane of its orbit and gives us seasons. Some people think summer comes when Earth moves closer to the Sun. The tilt is what gives us seasons. Mars looks red because iron in its rocks and dust has rusted.

Between Mars and Jupiter is a ring of rocks. There is a belt of asteroids, which are rocky space rocks, in that gap. More than a million asteroids orbit the Sun in this main belt. The belt is made of bits and pieces left over from the early solar system. They never came together into a planet.

Then comes Jupiter, the largest planet in our solar system. It is more than twice as massive as all the others combined. Jupiter is a gas giant, so it does not have a true solid surface. Galileo Galilei discovered its four largest moons: Io, Europa, Ganymede and Callisto. Its Great Red Spot is a giant storm that is bigger than Earth.

Saturn has a spectacular set of rings around it. Look closely, and the rings are not solid. They are made of millions of separate pieces, mostly small, from tiny dust-sized icy grains to chunks as big as a house. Saturn is also the only world in our solar system that is less dense than water. It would float in a bathtub big enough to hold it.

William Herschel discovered Uranus in 1781 with a telescope. Uranus appears to spin sideways as it goes around the Sun. Neptune is the windiest world in our solar system. It was found with the help of calculations. Experts predicted where it should be. Then Johann Galle located it through a telescope.

Our last stop is Pluto. Clyde Tombaugh discovered Pluto in 1930. Pluto was once counted as a planet, but as of November 2026 it is called a dwarf planet. As of that date, astronomers have recognized five dwarf planets.

Our trip ends back at the center. About 1.3 million Earths could fit inside the Sun. The Sun also holds 99.8 percent of all the mass in our solar system.

Words to know

• asteroids: rocky space rocks
• rusted: turned to rust
• dwarf: small kind
• mass: amount of stuff
• telescope: far-seeing tube