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Phys 1810 Lecture 13:

(Image unknown origin). Phys 1810 Lecture 13:. Planets, asteroids, comets: Use material in lecture as a guide for topics to read about in text book on each planet. READ BEFORE LECTURE: Solar System Chapt 6 Greenhouse effect P. 166-167, P. 231 Mars e.g. Box “More Precisesly 8-1”

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Phys 1810 Lecture 13:

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  1. (Image unknown origin) Phys 1810 Lecture 13: • Planets, asteroids, comets: Use material in lecture as a guide for topics to read about in text book on each planet. READ BEFORE LECTURE: • Solar System Chapt 6 • Greenhouse effect P. 166-167, P. 231 • Mars e.g. Box “More Precisesly 8-1” • formation of the moon 8.8 • exoplanets Chapt 15 Topics include • scale, objects • terrestrial vs jovian • planetary system formation including (differentiation) • Mars • Earth – climate change • planetary system formation including differentiation

  2. Jupiter’s Aurora • surrounding core is metallic H  B field  aurora • composition of core “rocky”

  3. the deep atmospheres of the gas giants may contain chunks of diamond floating in liquid hydrogen/helium fluid. • carbon such as soot or graphite generated in Saturn's enormous lightning storms will descend and be crushed into diamonds at deep altitudes and then melted into liquid diamond near the cores of the planets. • diamonds may be floating around inside of Saturn, some growing so large that they could perhaps be called "diamondbergs."

  4. Jupiter’s rings in IR

  5. Tour of the Solar System: Uranus Keck Observatory IR Weather • Rings

  6. Tour of the Solar System: Neptune Visible +IR Voyager2/NASA • Rings. • Seasons due to inclination of rotation axis to orbital plane.

  7. Saturn Cassini/NASA

  8. Tour of the Solar System: Saturn Cassini-Huygens/NASA/ESA • How did the rings form? Three possibilities. • Similar to a planetary disk formation but on a smaller scale. (We’ll do planetary disk formation shortly.) • Tidal forces causing orbiting low density moons to fragment.

  9. Saturn’s Moon Enceladus 3) Spewing ice plumes through (“blue”) tiger stripes  E ring

  10. Tour of the Solar System: Saturn Spitzer/NASA • Large Infra-red ring! (Moon Phoebe orbiting within this ring.) • diameter equivalent to 300 Saturns. • ~ 20 Saturns for its vertical height. • Too large for field of view of HST and too faint in visual range for optical telescopes.

  11. Saturn’s Moon Enceladus • has an atmosphere • Other moon’s with atmospheres: • Enceladus • Triton • Io • Titan • Dione

  12. News!

  13. Tour of Solar System: Saturn’s Moon Titan. Cassini-Huygens/NASA/ESA UV in false color • Atmosphere: Note upper layer of haze. • Thick enough to have polar vortex. • Seasonal changes due to tilt of spin axes.

  14. Titan Vortex is toxic • Spectral map • signature of frozen hydrogen cyanide molecules (HCN). • T atmosphere needs to be 125K (-148C) • suggests atmosphere of Titan's southern hemisphere (currently Autumn) is cooling much faster than expected.

  15. Tour of Solar System: Saturn’s Moon Titan. Cassini-Huygens/NASA/ESA Ontario Lacus at South Pole Visible + IR • Ethane lake. Ethane created by sunlight breaking apart methane. • Only other solar system object known to have liquid on the surface.

  16. Titan: “come and go” feature in lake. • dark areas represent the sea, composed of mostly methane & ethane (hydrocarbon). • bright areas represent land surface above or just beneath water line. • feature in bottom middle of image could be surface waves, rising bubbles, floating solids, solids that are suspended just below surface or perhaps something more exotic.

  17. Moon of Neptune: Triton • Triton has an atmosphere. • possibly a Pluto-like object that Neptune pulled into orbit. Voyager 1989 data processed in 2014

  18. Why study Mars instead of Venus? • Mars more likely to tell us how life originated in solar system • Venus too hostile due to its greenhouse effect.

  19. Greenhouse on Earth • Intergovernmental Panel on Climate Change. IPCC won Nobel Prize. • 1000s of scientists volunteer to IPCC. • Solar luminosity contribution to global warming (blue line above) is small. • increase in greenhouse gases (since industrial revolution ~ 1750) • See IPCC summary & FAQ on web.

  20. Greenhouse on Earth Note: these are not predicted values. • Details about these plots: • black line == measured data  T is rising. • Computer simulations use laws of physics & assumptions. Uncertainties width. • Blue: Modelling just natural forces (includes variation in sun’s luminosity) – stable T. • Pink: Modelling both natural forces & impact of human beings – match observed T better.

  21. New IPCC report – trends continue

  22. Greenhouse on Earth • These are measurements over time of amount of each green house gas. • Notice the “spike” is much higher in value than the uncertainties in the measurement.  spike is not an error.

  23. Sun’s Influence: On Earth Summary: The sun has influence throughout the solar system & our distance from it allows liquid water. However the solar cycle & activity is not responsible for global warming. Human activity is a likely cause. • Check the King’s Centre for Visualization in Science for interactives on climate change: http://www.kcvs.ca/site/projects/climate.html

  24. Greenhouse Effect • Venus has CO2 in atmosphere (volcanic outgassing) + too hot for oceans • -- CO2 not converted to rocks • runaway Greenhouse Effect. • inhospitable to life • Most light from sun is near-IR + visible. • IR trapped by greenhouse gases + H2O clouds. • recirculated for decades.  Mars of interest for life, colonization, etc.

  25. Mars • NASA/Viking

  26. Tour of the Solar System: Mars Mars Global Surveyor
Mars Orbiter Camera NASA/JPL/Malin • Radius ~ ½ of Earth’s; Mass ~ 1/10 of Earth’s. • Water ice crystals over volcanoes • Pole has water ice and CO2 ice. • Red soil due to iron.

  27. ESA/Mars Express

  28. Cydonia Region

  29. NASA’s Spirit and Opportunity rovers.

  30. Tour of the Solar System: Mars Spirit Rover/NASA • Typical surface temperature is -55C to -63C • Winnipeggers would survive! • Sometimes up to +20C.

  31. Olympus Mons • Evidence Mars cooled rapidly. • Different tectonic activity • B fld 1/800 Earth’s

  32. Viking Observations • Misinterpreted as a sculpted face.

  33. Stereo Camera on Mars Express • Movement of the crust raised this feature, called a massif.

  34. Example of Wind Action in Crater. Escape Velocity of molecules in atm. More Precisely Box 8-1

  35. Depletion of Upper Atmosphere • Charged particles from sun (solar wind) ionize molecules. • splits O from H (H escape) • solar wind drags ions away • Maven – new mission

  36. Depletion by: • UV photon heating  escape velocity to atoms • UV photon ionizing  charged particles • Solar wind ionizing  charged particles • ions dragged away by solar wind • A factor that does not play a role in depletion of the Martian atmosphere is outgassing from volcanoes.

  37. Martian Atmosphere. • Given the atmospheric pressure can liquid water currently exist on the surface of Mars?

  38. Water Ice in a crater.

  39. Mars and Water Mars Global Surveyor
Mars Orbiter Camera NASA/JPL/Malin • Water ice crystals over volcanoes • Pole has water ice and CO2 ice.

  40. Vallis Marineris • Vapour

  41. Current Phases of Water on Mars. • Clouds

  42. Tour of the Solar System: Mars Viking/NASA • Atmosphere is 1/150 of Earth’s (~ 1%) • 95% CO2 • Pressure < 60% ice sublimates into gas

  43. Tour of the Solar System: Mars Viking/NASA • Vapour and clouds – settle in valleys and channels. • Currently no detection of liquid water, though rivers may have flowed in the past when the atmosphere was denser.

  44. Outflow Channels • Abundances  95% CO2 on Mars. • Using current abundances & working backwards in time & using escape velocity  denser atmosphere in past. • Also probably similar to composition of Earth’s early atmosphere. Look for evidence of liquid water in the past.

  45. Curiosity Rover --- 7 Minutes of Terror

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