Journey through our solar system and explore the wonders of the cosmos
Our solar system consists of a star—the Sun—and everything bound to it by gravity: eight planets, dwarf planets, moons, millions of asteroids, comets, and meteoroids.
The Sun is the star at the center of our solar system. It's a nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core.
The Milky Way is the galaxy that contains our Solar System. The name describes the galaxy's appearance from Earth: a hazy band of light seen in the night sky.
The observable universe is about 93 billion light-years in diameter. It contains an estimated 100–200 billion galaxies, each with billions of stars.
Black holes are regions of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it.
Exoplanets are planets that orbit stars outside our solar system. Thousands have been discovered in recent years, some in the habitable zones of their stars.