1 / 174

The Solar System

Discover the fascinating geology and atmospheric evolution of the inner planets in our solar system. Learn about the scrambled and fried asteroids, the outer planets and their mini-solar systems of moons, and the enigmatic nature of comets. Explore the characteristics of inner versus outer planets, the relationship between temperature and distance in the solar system, and the sizes of all planets compared to the sun. Finally, delve into the question of how planets retain their atmospheres and the two primary ways they can lose them.

lbaxter
Download Presentation

The Solar System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. The Solar System Inner planets; geology, atmosphere evolution The asteroids – scrambled and fried Outer planets and their mini-solar systems of moons Comets: icy dirtballs or dirty iceballs?

  2. Inner vs. Outer Planets characteristics

  3. Temp vs distance in solar system

  4. All planets and the sun, sizes

  5. How Does a Planet Retain an Atmosphere? • Surface gravity must be high enough and surface temperature must be low enough that the atmosphere molecules don’t leak away during the 4.6 billion years since formation.

  6. Two Ways a Planet Loses Atmosphere: First… • Lighter molecules move faster, because on average Kinetic Energy = Thermal Energy • (½)m<v>2 = (3/2)kT • Molecules are continually bouncing off of each other and changing their speed, but if the average speed is higher, a few may be speedy enough to escape the planet’s gravity • Hydrogen and Helium = 97% of the mass of the solar nebula, and these are the lightest and easiest molecules to lose

  7. The Second way to Lose Atmosphere… • …maybe easier to understand - Impact Cratering! Big comets and asteroids hitting the planet will deposit a lot of kinetic energy which becomes heat, blowing off a significant amount of atmosphere all at once. • This is a Big issue especially in dense areas (inner solar system), and dense times (soon after formation).

  8. The Inner Planets • It’s hot close to the sun. No ices. So only the rocky material (~3% of the solar nebula) could collect. Not hydrogen and helium since escape velocities that are too low for these • Atmosphere histories for each planet are unique…as we’ll see

  9. Early inner planet; a ball of lava

  10. Inner planet interiors; summary

  11. Mercury mariner

  12. Mercury mud cracks

  13. Mercury fault

  14. Mercury • Smallest planet, only 3,000 mi across. • 600F on daylight side, too hot to retain any atmospheric molecules at all. Probably doesn’t help that the sun is so close and solar storms can rack the planet and help carry off any atmosphere too. • Cratering shows it hasn’t had atmosphere for most of solar system’s history

  15. venusHST

  16. Venus-all

  17. Venus lava flows

  18. Venus-surface1

  19. Venus-surface2

  20. Venus-surface4

  21. Venera-left

  22. Venera-right

  23. Venus • Has thick CO2 atmosphere, 100 times denser than earth’s. CO2 is the heaviest common molecule. • Greenhouse effect – CO2 transparent to visible light coming down from the sun, but opaque to infrared coming back off the surface, hence heat comes in but can’t easily escape. 900K on surface!! • Let me draw you a picture…

  24. Greenhouse effect

  25. Earth – largest inner planet • Crust divided into tectonic plates which move due to friction against the moving molten mantle underneath. Continental drift animation • . Click here for animation website. • This likely explains why the earth has so little atmosphere. That’s one heck of an impact event.

  26. Atmosphere; initially rich in CO2, methane, no oxygen Why so little atmosphere, and why is CO2 such a tiny % (~0.3% today)? 1. Life took out CO2 and produced O2, and organic and inorganic processes produced CaCO3. Nice! This has been lowering greenhouse gases at the same time the sun has been increasing its luminosity – balance! 2. Moon created by Mars-sized planet impacting early Earth. Evidence: (1) moon crustal age is a little younger than Earth’s, (2) moon composition = Earth mantel composition, (3) moon orbits ~in ecliptic, not equator plane as you would expect if it was formed with the earth.

  27. Folded mountains – earth and Venus

  28. Aurora, iceland volcano

  29. Mt. Aetna in italy

  30. Ozone hole

  31. moonPlieades

  32. moon

  33. Moon’s surface; maria vs highlands

  34. Mare humorum,

  35. Clavius 160mi across

  36. Apollo 15 on moon1

  37. Apollo 15 on moon

  38. Graze reduction

  39. marsHS

  40. Mars globe, big craters

  41. Mars globe, w/ v. marinaris

  42. Olympic mons caldera

  43. Mars valle marinaris

  44. Mars continents

  45. Mars solis plenum

  46. Martian sand dunes

  47. Mars gullies

  48. Martian surface; pathfinder

  49. Spirit track

  50. Mars mud cracks

More Related