Explore Worlds
Find Life
Defend Earth
Where did we come from? Are we alone in the Universe? We can only answer these questions by exploring the planets and other worlds of our solar system and beyond. Learn why these worlds are so important, and how you can get involved.
Mercury, Planet of Extremes
Mercury can teach us how planets form and what the early solar system was like when life arose on Earth.
Your Guide to Venus
Venus may have had oceans and been habitable to life before being transformed into an inhospitable wasteland.
Earth
Earth is our home and the only world known so far to harbor life.
Your Guide to the Moon
The Moon is the only world besides Earth ever visited by humans. By studying it, scientists can piece together Earth’s origin story.
Mars, the Red Planet
Mars once had liquid water on the surface and could have supported life. We don't know how it changed to the cold, dry desert-world it is today.
Asteroids, Comets, and Other Worlds
These leftover planet-building materials are like time capsules that give us a peek into our origins.
Your Guide to Jupiter
Jupiter, our largest planet, teaches us how solar systems evolve. Its four planet-like moons make it a solar system of its own.
Your Guide to Saturn
Saturn is the crown jewel of our solar system. It has a stunning set of rings, diverse moons, and so much more to explore.
Your Guide to Uranus
Uranus may be the butt of all planet jokes, but there's much more to this world than potty humor.
Your Guide to Neptune
Neptune, our outermost planet, is a windy blue world with exotic ice, raging storms, rings, and a moon that could have a subsurface ocean.
Your Guide to Exoplanets
We know of more than 4,000 planets orbiting other stars. Does one of them host life as we know it?
A Pale Blue Dot
Look again at that dot. That's here. That's home. That's us.
What is a Planet?
It's right there in our name: The Planetary Society. But what is a planet? This seemingly simple question is the subject of much debate.
Learn MoreLatest Articles
How did our solar system come to be? Why are the planets, asteroids, comets, and other small worlds where they are now?
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Extraordinary claims require extraordinary evidence, so here are the reasons why there may or may not be aliens in our cosmic backyard.