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In Search of Habitable Worlds and Life in the Universe

Explore the possibility of life beyond Earth by examining potential habitable worlds and the universal laws of biology. This includes the search for liquid water, intelligence DNA, and the existence of life in our solar system and beyond.

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In Search of Habitable Worlds and Life in the Universe

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  1. Searching for Habitable New Worlds and Life in the Universe Hosted by Night Sky Network

  2. Universal Laws of Biology ? DNA Intelligence Liquid Water Lawrence Hall of Science

  3. The Only Known Site of Biology In the Universe. Is there life elsewhere in our Solar System?

  4. Mars Liquid Water Impossible Pressure = 0.01 of Earth . . . too low for Liquid water.

  5. Jupiter and Two Moons Io Europa

  6. Surface of Jupiter’s Moon: :Europa Fractures in Floating Ice Icebergs

  7. Jupiter’s Moon:Europa Sub-Crust Ocean . . . . Hydrogen-Carbon compounds likely: Amino acids Life in the Ocean? First New Ocean Since Balboa

  8. . Now Exiting our Solar System to … TheMilky Way Galaxy . . . Meanwhile, we are hunting for abodes Beyond our Solar System . . . . . . . . .

  9. The Discovery of Other Planetary Systems & Implications www.exoplanets.org Collaborators: Paul Butler,Debra Fischer, Steve Vogt Chris Tinney, Greg Laughlin, Hugh Jones Andrew Cumming, Greg Henry, Jack Lissauer Jason Wright, Brad Carter, Eugenio Rivera, Chris McCarthy, John Johnson

  10. Planet Detection Wobble of Star: Gravitational pull by the planet

  11. WobbleVelocity VPL2 =G MStar / rVPL ~ 10 km/s VStar = VPLVSTAR~ 10 m/s x(MPL /MJUP) Energy Equipartition: Momentum: ) ( MPL MSTAR

  12. . . . Jupiter 12 years (Meters/sec) Need Telescope . . .

  13. 1997 – Present World’s most Successful Planet Search Keck 1 Survey: 1300 Nearby Stars

  14. High Resolution ``Echelle” Starlight From Telescope Echelle Spectrometer Spectrometer CCD Echelle Grating Collimator

  15. Spectrum of Star:Doppler Effect Doppler Precision: v / c ~ 10-9 Dl / l ~ 10-9 4096 Pixels

  16. 16 Cygni B Mass = 1.7 MJUP (Min) Not Sinusoidal Orbit Period Velocity Wobble 2.2 yr

  17. Orbit of Planet around 16 Cygni

  18. 16 Cygni: Planet & Moon

  19. Life on Gas Giant Planets ? ? Unlikely Earth-Like Moon Floaters

  20. Mass = 0.62 MJUP 70 Days

  21. Upsilon Andromedae: Velocity Residuals

  22. . Upsilon Andromedae: Triple Planet System . Planets have No Names . 2 MJUP . . 0.6 MJUP . 4 MJup . .

  23. Upsilon Andromedae

  24. Gliese 876 d Lowest Mass Exoplanet : 7.5 Earth-Masses Per = 1.94 d M = 7.5 MEarth 1.94 Days 5 m/s

  25. Three Planets Orbiting Gliese 876 7 1/2 Earth-masses

  26. 7.5 Earth-Mass Planet Orbiting Gliese 876 Ring in Between: Lukewarm Tides: One Planet Side always Faces Star Hot: 370 C Cold: -100 C

  27. Milky Way Galaxy 200 billion stars ~10% of all Stars have detected planets. 20 Billion Planetary Systems • Detected so far: • Jupiter-mass • Saturn-mass • Neptune-mass ~ Earth-Mass ?

  28. More Low-Mass Planets Planet Mass

  29. Conclusion: Many Earth-mass Planets Only Known Abode of Life But are they Habitable ? Must Environments Be “Just Right” For Life ?

  30. One of the Least Hospitable Places on Earth: Yellowstone National Park : Suitable for Life ? • Boiling Geysers • Freezing winter • Sulfuric acid.

  31. YellowstonePinwheel Geyser Near Boiling: T ~ 80 C Bacteria Thrive Each color a different species of bacterium Water: Acidic as battery acid

  32. Yellowstone Life at High Temperatureand High Acidity Temp = 65 C pH = 2

  33. YellowstoneChurning Cauldron Boiling Temp

  34. YellowstoneChurning Cauldron Boiling Temp, pH = 2 Algae Bacteria & Algae Thrive Corrosion pH = 2

  35. Cyanidium Calderium Life at Extreme Temp & Extreme Acidity Lives only at T > 60 C

  36. Extremophiles Show that Life • Tolerates heat or cold • Thrives in acidic or alkaline environments • Takes food from a variety of sources • Copes with Intense Solar Radiation - - or none! Liquid Water Life Primitive Life: Common in the Universe

  37. Is our Milky Way GalaxyTeeming with Intelligent Life ? • Galaxy is • 10 Billion Years Old • - - - Twice the Age of Earth • 50% of Stars are • as Old as the Sun & Earth • Many stars & planets older by billions of years! • How Many Civilizations ?

  38. Is our Milky Way Teemingwith Intelligent Life ? • 20 Billion • Planetary Systems: • 1/2 are older than Earth • What fraction have • Intelligent Life? • Pessimist: 1 in a Million Advanced There must be Thousands of Civilizations In the Milky Way Galaxy. . .

  39. . . . . . . . . . . . . . .

  40. Where is Everybody?Why Didn’t They Come Here? • Moon: No Alien Spacecraft, Crash Debris, Obelisk • Mars: Same Story • Earth: Lovely Planet for 4 Billion Years . . . Yet, no Alien Settlement. • 100’s of Telescopes: No Alien Ships spotted • Night Sky: No Exotic Rocket Exhaust • No Robotic Probes Visit Solar System • SETI: No Radio Signals in 40 years.

  41. Where Is Everybody? • Hypothesis: - Thousands of Civilizations in Galaxy - Head Start of Billions of years. They should be Near! • Migration Throughout Galaxy:Easy with robotic spacecraft ================================================= • Observation:No Aliens Detected, and no Traces. • Conclusion:Hypothesis possibly flawed. ( Ants eventually find your Kitchen)

  42. Expect: 1000Civilizations in 5 Billion Years . For Multiple Civilizations Today, Lifetimes Must Overlap: Lifetime > 5 Million yr How Long do Technological Civilizations Last?

  43. February 5, 1996 • Recipe for • Exobiology: • Planets • Chemicals • Water • Energy - - - • Stars, Tidal, Geothermal Life: Probably Common in the Universe. Primitive Life, at least

  44. SETIATA: Proposed Radio Telescope Array

  45. Life in our Milky Way Galaxy:Primitive Life: CommonIntelligence:Rare ? Semi-Intelligent Life forms .. Intelligence

  46. www.exoplanets.org

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