1. The Volcanoes of Io

2. Sulfur dioxide As temp increases: white yellow orange brown black

3. Sulfur dioxide As temp increases: white yellow orange brown black Volcanoes! ~200 volcanoes Most geologically active body?

4. Geologically Active... Internal heat: Left over from formation?

5. Geologically Active... Internal heat: Left over from formation? Heat from the Sun?

6. Geologically Active... Internal heat: Left over from formation? Heat from the Sun? So where is it coming from...?

7. Tidal Heating! 1. Orbital resonances → elliptical orbit

8. Tidal Heating! 1. Orbital resonances → elliptical orbit 2. Io is a BIG MOON

9. Tidal Heating! 1. Orbital resonances → elliptical orbit 2. Io is a BIG MOON 3. Jupiter is MASSIVE → large gravitational force

10. Tidal Heating! 1. Orbital resonances → elliptical orbit 2. Io is a BIG MOON 3. Jupiter is MASSIVE → large gravitational force

11. Tidal Heating! 1. Orbital resonances → elliptical orbit 2. Io is a BIG MOON 3. Jupiter is MASSIVE → large gravitational force (what if Io was tiny?) (what if Europa and Ganymede weren't there?)

14. Studying Io and its Volcanoes Optical light 5.2 AU → 4% of sunlight Earth receives

15. Studying Io and its Volcanoes Optical light 5.2 AU → 4% of sunlight Earth receives Night vision goggles! (Infrared light)

16. Studying Io and its Volcanoes Optical light 5.2 AU → 4% of sunlight Earth receives Night vision goggles! (Infrared light) Higher temperature Lower temperature Wavelength tells us something about temperature...

17. Blackbody Radiation What gives off blackbody radiation? Stars, planets, light bulbs, stoves, fire, people, etc

18. Blackbody Radiation Wavelength: micrometers (0.000001 meters) Temperature: Kelvins (300 K is ~70F) Always positive!

19. Blackbody Radiation Total energy emitted is proportional to T 4 Wein's Law: Wavelength * T = 3670