Title: Exoplanets, Worlds Orbiting Other Stars | The Planetary Society
Headings: Exoplanets, Worlds Orbiting Other Stars
Exoplanets, Worlds Orbiting Other Stars
Facts Worth Sharing
Why study exoplanets?
The Different Kinds of Exoplanets You Meet in the Milky Way
How do we study exoplanets?
How to Search for Exoplanets
Active Exoplanets Missions
Future Exoplanets Missions
Earth-sized or Earth-like?
What Is the Habitable Zone?
What can you do to advance exoplanet research?
Our Exoplanets Projects
Three ways you can be a space advocate

Content: You’ll often hear the term “Earth-like” used to describe worlds that resemble our own. Generally speaking, this means the planet might have liquid water and an atmosphere that could support life as we know it. Life on other worlds may be unrecognizably different from what we know here on Earth, and even life on our planet is extraordinarily diverse. But it makes sense to start by looking for worlds that resemble our own. Earth-sized or Earth-like? It’s important to distinguish “Earth-like” from “Earth-sized” when reading news stories about exoplanets; just because a planet is about the same size as Earth doesn’t mean it could support life (Hello, Venus!). So how do we look for Earth-like planets? The most basic condition for being able to sustain liquid water is the planet’s position in relation to its star. Scientists call the region around a star where liquid water can exist on the surface of a planet the habitable zone: