Astronomer Philip Plait — who fell in love with Saturn after first viewing the gas giant, with its mesmerizing rings and moons, through a telescope as a child — shares some of the amazing discoveries we've made about the planet in recent years. Then actor Martin Sheen describes how his travels in the developing world have opened his eyes, and his heart, to the needs of others. And a Florence-based tour guide and culinary expert lets us in on where to find the best food in her adopted home.

• Astronomer Philip Plait, author of "Under Alien Skies" (W. W. Norton)
• Actor Martin Sheen
• Florence, Italy-based tour guide Toni Mazzaglia

• Astronomer Philip Plait is the author of "Under Alien Skies." He also writes frequent updates for his subscription-based Bad Astronomy newsletter on Substack, and posts weekly articles at Scientific American.
• Saturn's hexagon, explained.
• Philip Plait spoke with Rick about a "Sightseer's Guide to the Solar System" on Travel with Rick Steves program #736 in December 2023.
• Martin Sheen's and his son Emilio Estevez's movie "The Way" was originally released in 2010. The revised 2023 version, which includes a conversation with Rick at the end, is available to watch on multiple streaming services.
• Information about Martin Sheen's career, personal life, and political activism is included on his Wikipedia page.
• Martin Sheen spoke further with Rick about the influence of his travels on his view of the world, on Travel with Rick Steves program #715 in May 2023. Martin's son Emilio Estevez joined in on program #713.
• Toni Mazzaglia operates the Taste Florence walking tours to food and wine venues in Florence.
• The Rick Steves online guide to Florence, Italy.
• Toni spoke with Rick about the "Flavors of Florence" on Travel with Rick Steves program #707 in March 2023.