Co-founded by Carl Sagan in 1980, The Planetary Society is a member-funded nonprofit organization dedicated to advancing space science and exploration through three core enterprises.

What’s up in the night sky: January 2026 Our monthly feature focuses on easy and fun things to see in the night sky, including eclipses, supermoons, meteor showers, planetary conjunctions, and more.

The latest stories from The Planetary Society, featuring humanity's quest to explore worlds, find life, and defend Earth.

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

We connect with planetary exploration experts from around the world to strengthen our work and support international exploration efforts. Our 50,000+ international membership makes us the largest, …

Jul 25, 2024 · Astronomers would “like to understand the trends, how rotation rate depends on planetary mass, and then link it to formation models,” said Helled. Batygin said one of his motivations for trying …

We bring planetary defense experts together from around the world to work on advancing solutions to the asteroid threat. We co-sponsor, attend, and organize activities at academic conferences, …

This print by artist and Planetary Society supporter Anna Moore, titled “Orbit,” shows a repeating pattern of spacecraft around our planet. “Orbit” captures the role of technology in space science and …

Apr 16, 2025 · The Planetary Society was formed in a time when planetary science was essentially dead, and we hadn't seen any missions on the horizon. This is exactly why Carl Sagan, Bruce …

Jan 30, 2025 · From funding early Mars rover testing to naming planetary bodies and developing sample return technologies, Planetary Society members have funded contributions to more than 20 missions …