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.

They established The Planetary Society to give anyone from anywhere in the world an active role in advancing space exploration. Today, The Planetary Society continues this work, under the …

What’s up in the night sky: December 2025 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.

Dec 8, 2025 · In response, The Planetary Society launched a campaign to save NASA science. What came after has been a banner year for space advocacy that has resulted in some tangible wins …

Dec 9, 2025 · The Planetary Science Caucus, now in its second year, is officially reorganized and has hit the ground running; organizing against the devastating proposed cuts and rallying bipartisan …

For over 4 decades, our members have made strides in advancing planetary exploration, planetary defense, and the search for life beyond Earth. We have delivered tens of thousands of petitions to …

Together with our members and supporters, we’re on a mission to explore worlds, find life off Earth, and protect our planet from dangerous asteroids. Join us at planetary.org.

To figure out where that boundary lies, and how geoscientists might classify planets, it helps to know what planetary scientists have learned about the variety of worlds in our solar system, and which …

Explore the membership options of The Planetary Society and join fellow space enthusiasts in advancing space science and exploration.