Pluto: the next decade of discovery

1. Pluto: the next decade of discovery Leslie Young Southwest Research Institute layoung@boulder.swri.edu

2. I. Decade-scale surface-atmosphere interaction

3. 2005: 30.9 AU, 34° sub-solar lat 2015: 32.8 AU, 49° sub-solar lat Farther at 0.2 AU/year distance, More northerly at 1.5 °/year.

5. 2005-2015, distance increases by 6%, insolation decreases by 12%. Simplest models have temperature decreasing by 3% (~1.2K),for the pressure nearly halving.

6. Sicardy et al. 2003, Nature 424 Elliot et al. 2003, Nature 424

7. Hansen and Paige fig 3 (high thermal inertia) perihelion 1000 year 1200 Hansen and Paige 1996, Icarus 120

8. Hansen and Paige fig 4 (moderate thermal inertia) perihelion 1000 year 1200

9. Hansen and Paige fig 7 (low thermal inertia) perihelion 1000 year 1200

10. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

11. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

12. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

13. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

14. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

15. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

16. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

17. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

18. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

19. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

20. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

21. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

22. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

23. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

24. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

25. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

26. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

27. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

28. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

29. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

30. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

31. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

32. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

33. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

34. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

35. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

36. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

37. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

38. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

39. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

40. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

41. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

42. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

43. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

44. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

45. Darkening of ices following sublimation Thermal inertia Old, frost-covered winter pole coming into sunlight

46. II. Distinguishing seasonal models with observations

47. 1954.8 1964.4 1975.2 1982.2 Stern et al. 1988, Icarus 75 Buie et al. 1997, Icarus 125 1992/93 Changes in lightcurve mean and amplitude can be due to volatile transport or changing viewing.

48. Douté et al 1999, Icarus 142 CH4 CO N2 Spectra on the surface absorption in reflected sunlight is diagnostic of the volatiles on Pluto's surface, including their grain size, mixing state, and temperature. 0.8-2.5 µm range includes N2, CH4, and CO. Shorter wavelengths include weak CH4 bands, and CH4 and tholins have absorption at 3.3 µm (See Olkin 55.02).

49. Hansen and Paige 1996, Icarus 120 1300 µm brightess temperature 60 µm brightness temperature N2 frost temperature 1000 year 1200

50. Young 2004, BAAS Occultations are the most sensitive and direct measure of changes in atmospheric pressure.