Discover Alien Worlds
What Are Exoplanets?
Exoplanets are planets orbiting stars beyond our Sun. Over 5,700 discovered, some might have oceans or life!
Habitable zones
The "Goldilocks zone" around a star—not too hot, not too cold—where liquid water could exist on a planet's surface. This is where we hunt for worlds that might support life, just like Earth!
Earth-sized
These rocky planets are about the same size as Earth—perfect for imagining mountains, oceans, or even life! Many orbit distant stars, and some could be just right for liquid water. Over 200 discovered so far!
Gas Giants
Massive gas giants like Jupiter, but taken to the extreme—some scorch close to their stars with molten glass rain and 5,000 mph winds, others puff up like balloons from heat, and a few drift alone in the void with no star at all. The first exoplanets ever discovered were in this class!
Ice Giants
Neptune-class worlds of ice, gas, and wild weather. Some orbit so close their atmospheres stream off like comet tails. Others sit farther out, cold and blue, closer to the ice giants in our own backyard.
Sub-Neptunes
Worlds bigger than Earth and smaller than Neptune — the most common size we keep finding, and the hardest to picture. Thick skies, possible water layers, and hazy envelopes hide what’s underneath. They’re the missing middle of the planetary family.
Exoplanets are planets orbiting stars beyond our Sun. Since the 1990s, astronomers have confirmed thousands of them — rocky Earth-sized worlds, puffy sub-Neptunes, ice giants, and extreme gas giants — and the count keeps climbing thanks to Kepler, TESS, JWST, and missions still coming online.
Some are scorching hot gas giants with molten glass rain. Others are rocky worlds about Earth’s size, orbiting in the “habitable zone” where liquid water could exist. A few might even have oceans or atmospheres that could support life as we know it.
Exploring exoplanets helps us understand our place in the universe: Are we rare, or is the galaxy full of potential homes for life? Every new discovery brings us closer to answering that question.