Overview
This lecture focuses on Saturn’s moon Titan, its thick atmosphere, unique weather, and methane-based lakes and rivers, along with a brief look at another Saturnian moon, Mimas.
Titan: Saturn's Largest Moon
- Titan is a moon of Saturn with a thick nitrogen-rich atmosphere.
- It is the only moon in the solar system with a substantial atmosphere similar in composition to Earth’s.
- The surface of Titan cannot be seen from space because of this dense atmosphere.
- Titan’s gravity is similar to Earth's moon, but its cold temperature allows it to retain its atmosphere.
- Space probes have landed on Titan and taken descent and surface photos.
Surface Features and Weather on Titan
- Photos from the probe show river-like valleys and large reflective patches interpreted as lakes or seas.
- Titan is the only place in the solar system confirmed to have flowing rivers and precipitation.
- The rivers and lakes on Titan are not water but primarily liquid methane.
- Water on Titan is frozen solid, forming dirty ice “rocks” on the surface.
- Methane lakes and rivers occur because at Titan's low temperatures, methane can exist as a liquid.
Fun Facts about Methane on Titan
- Methane, the main component of Titan's liquid lakes and rain, is also present in human flatulence.
- Methane gas is colorless in small amounts but appears blue when highly concentrated.
Other Notable Saturnian Moons
- Mimas, another of Saturn’s moons, is noted for its large crater, making it resemble the Death Star.
Key Terms & Definitions
- Titan — Saturn’s largest moon, notable for its thick nitrogen atmosphere and methane lakes.
- Methane — A simple hydrocarbon (CH₄), liquid on Titan’s surface due to low temperatures.
- Atmosphere — The layer of gases surrounding a planet or moon.
- Mimas — A small moon of Saturn identifiable by a large impact crater.
Action Items / Next Steps
- Review Chapter 8, especially the end-of-chapter video of the probe’s descent to Titan’s surface.