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: March 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.

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 …

We provide free, accessible information to the public like our weekly radio program and podcast Planetary Radio, videos, articles, social media, The Planetary Report magazine, public events, and …

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

Our monthly feature focuses on easy and fun things to see in the night sky, including eclipses, supermoons, meteor showers, planetary conjunctions, and…

Apr 21, 2020 · 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.

Jan 15, 2026 · 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 …

Jan 1, 2026 · Feb. 28: Planetary alignment. Six planets — Mercury, Venus, Jupiter, Saturn, Uranus, and Neptune — will trace an arc across the night sky, though some (Venus, Jupiter, Saturn) will be much …