1. Chapter 11: Part 1 Pluto and the Dwarf Planets

2. Pluto was discovered by Clyde Tombaugh in 1930 by comparing one image of the sky taken one night with an image taken 6 nights later. Pluto: Ruler of the Underworld

3. The discovery of Charon

4. Charon and Pluto

5. HST discovers new moons! 2012

6. Strange object; located far out from the Sun with gas giants but small size and very elliptical and highly inclined orbit Pluto is a mixture of ices and rocks composition similar to satellites of giant planets Could be captured Kuiper Belt Object (e.g. comet)? What is Pluto?

7. Pluto’s strange orbit

8. Quaoar, Sedna, Earth, Moon, and Pluto size comparisons

9. 10 th Planet???

10. A "planet" is a celestial body that: (a) is in orbit around a star, (b) has a nearly round shape (c) and has cleared the neighborhood around its orbit. 8 Planets ! IAU Definition

11. Planets sweep up all the material along their orbit

12. Pluto’s strange orbit

13. Dwarf Planet Orbits are Strange

14. A “dwarf planet is” a celestial body that: (a) is in orbit around the Sun, (b) has a nearly round shape (c) has not cleared the neighborhood around its orbit and is not a satellite 5+ Dwarf Planets ! Dwarf Planet Definition

15. New Horizons visits Pluto July 2015

16. Pluto revealed!

17. Pluto and Charon