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.
The Sun, our Solar System’s star
Our Sun is an active star, frequently bursting out storms of plasma and radiation into the Solar System.
Mercury, world of extremes
Mercury can teach us how planets form and what the early solar system was like when life arose on Earth.
Venus, Earth's twin sister
Venus may have had oceans and been habitable to life before being transformed into an inhospitable wasteland.
Earth, the only planet known to support life, offers liquid water, an oxygen-rich atmosphere, and protection from the Sun’s harmful radiation.
The Moon, preserving Earth's origin story
The Moon is the only world besides Earth ever visited by humans. By studying it, scientists can piece together Earth’s origin story.
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 small worlds
These leftover planet-building materials are time capsules that give us a peek into our origins.
Jupiter, the planet with a planetary system of its own
Jupiter, our largest planet, teaches us how planetary systems evolve. Its four planet-like moons make it a planetary system of its own.
Io, Jupiter’s chaotic volcano moon
Io, one of Jupiter's four Galilean moons, is known for its explosivity.
Europa, Jupiter’s possible watery moon
Europa is the sixth-largest moon in the solar system and Jupiter’s fourth-largest satellite.
Saturn, planet of rings, moons and more to explore
Saturn is the crown jewel of our solar system. It has a stunning set of rings, diverse moons, and so much more to explore.
Enceladus, Saturn’s moon with a hidden ocean
With its subsurface ocean and so-called "tiger stripes," Enceladus is one of Saturn's most fascinating moons.
Titan, a moon with familiar vistas
Saturn's largest moon, Titan, is both the only other place in the solar system with liquid on its surface and the only moon with a thick atmosphere, making it a tantalizing destination to search for life.
Uranus, the sideways planet
Uranus may be the butt of all planet jokes, but there's much more to this world than potty humor.
Neptune, planet of wind and ice
Neptune, our outermost planet, is a windy blue world with exotic ice, raging storms, rings, and a moon that could have a subsurface ocean.
Triton, Neptune's largest moon
Triton is likely a captured Kuiper Belt Object and possibly an ocean world.
Pluto, the Kuiper Belt’s most famous dwarf planet
Pluto is a dwarf planet and the largest of the Kuiper Belt objects (KBOs) — a collection of ice-rock bodies found outside Neptune’s orbit.
Exoplanets, worlds orbiting other stars
We know of more than 5,000 planets orbiting other stars. Does one of them host life as we know it?
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 More
What the search for aliens can learn from life on Earth
When searching for extraterrestrial life, we have to base our hunt on what we know about life on our own planet. This may seem limiting, but there's a lot we can learn from the astonishingly diverse lifeforms we have here on Earth.
Scientists spot possible signs of active volcanism on Venus
The findings bolster long-held suspicions that the planet, which is covered in volcanic rock, is still active today.
The secrets of Jupiter’s tiny new moons
Jupiter's 92 confirmed moons can teach us how the giant planets formed, and what conditions were like in the early Solar System.
Our favorite moons of the Solar System
A brief guide to eight of our Solar System's most fascinating and scientifically promising moons.