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: Or inhabited? Imagine what our Sun and Earth would look like from a few hundred light-years away. Using our present-day technologies, you might be able to determine that Earth is a small, rocky planet that sits in the Sun's habitable zone. Next, you could look for signs of water in the Earth's atmosphere, to rule out it wasn't a dry, desert planet like Mars. Our current technologies are just barely capable of doing this, while upcoming ground and space-based observatories will be able to do it even better . By then, you might be able to conclude Earth was habitable. But to tell if there was actually life on the surface, you'd need to find gases in the planet's atmosphere like ozone that are possible byproducts of life. Our current and near-future telescopes won't be able to do this, but several proposed space telescopes might. Even then, you probably wouldn't be able to say for certain that you'd found life. Ultimately, it could take something like a telescope that uses our Sun's gravity as a giant lens to capture a sharp picture of an exoplanet and see signs of life on the surface.