It’s been a big year here at The Planetary Society. To recap the highlights, listen to this week’s Planetary Radio for interviews with several members of our team as we revisit some of 2023’s groundbreaking discoveries, Society achievements, and favorite space exploration moments. Pictured: A highlight of the year was the Lucy spacecraft’s discovery of a pair of tiny asteroid moonlets orbiting a larger asteroid. Image credit: NASA/Goddard/SwRI/Johns Hopkins APL.
Is one of your New Year’s resolutions to read more? If so, be sure to join The Planetary Society’s book club. We meet virtually every month to discuss a new space-related book with the author or a related expert. This month’s book is “A City on Mars” by Kelly and Zach Weinersmith, which explores what it would really take to settle on another world. The authors will join host Mat Kaplan for a live Q&A on Jan. 4. It all happens in our members-only digital community. If you aren’t already a member, join today!
The Galilean moons were discovered almost exactly 414 years ago. The Italian astronomer Galileo Galilei first observed these four moons through a telescope in early January 1610, forever changing our understanding of the Cosmos. Io, Europa, Ganymede, and Callisto, collectively known as the Galilean moons, are Jupiter’s four largest moons, and were the first moons other than Earth’s to be discovered. Learn more about why that made such a big impact, and what we know about these fascinating worlds.