1. Life in the Universe 029:062 Guest Lecture Catherine Whiting

2. Life in the Universe What are the chances of extraterrestrial life in the universe? – How common are extrasolar planets? – How many of these planets are suitable for life? (at least earth-like life) – What characteristics would this life possess? – How would we make contact?

3. Extrasolar Planets Detection Methods

4. Extrasolar Planets Detection Methods – Eclipses

5. Extrasolar Planets Detection Methods – Doppler Shifts – planet causes star to wobble

6. Extrasolar Planets Detection Methods – Imaging HR 8799 Infrared Image Planets only 60 million years old- still glowing from formation

8. Extrasolar Planets Detection Methods – Eclipses, Doppler Shifts, Imaging – Subject to selection effects- meaning we tend to detect mostly Jupiter-like planets that are close to their stars because our detection methods are best-suited to detecting Jupiter-like planets – Earth-like planets now being detected - Kepler Mission

9. Example: Gliese 581 Red dwarf star 20.3 light years away At least 6 known planets- some could support life

10. Habitable Zone Life on Earth appears to require water Planets with water may be the most promising places for life In order to have liquid water, the temperature of the planet must be between freezing and boiling points This limits its distance from its star- Habitable Zone-

11. Habitable Zone

13. More than 450 new planets have been discovered since 1995

14. 99% of all organic material consists of 4 elements: Hydrogen, Carbon, Oxygen, Nitrogen

15. Chemical Abundances in Stars

16. Ammonia, Methane, Water + Lightning= Amino Acids !

17. Cosmos Episode 2: time: 46:15 http://www.youtube.com/watch?v=p1Zh69TB 0lU http://www.youtube.com/watch?v=p1Zh69TB 0lU Miller-Urey Experiment

18. Drake Equation Carl Sagan Video: http://www.youtube.com/watch?v=MlikCebQ SlY&feature=related http://www.youtube.com/watch?v=MlikCebQ SlY&feature=related Carl Sagan translated for rednecks: http://www.youtube.com/watch?v=DI9ImScQ GAo&feature=related http://www.youtube.com/watch?v=DI9ImScQ GAo&feature=related

19. What would aliens look like? Cosmos Episode 2: time: 52:50 http://www.youtube.com/watch?v=p1Zh69TB0l U

24. Discussion Questions Would alien civilizations be hostile? Are aliens already secretly here? – Colonization, government conspiracy – Would we even be able to comprehend them?

25. SETI (Search for ExtraTerrestrial Intelligence) If there are other civilizations out there, are they trying to contact us? There are active searches for ET signals, mainly in the radio, some using visible light.

26. Arecibo Message

27. Voyager

28. Voyager Decoded

29. Voyager Message http://voyager.jpl.nasa.gov/spacecraft/index.h tml http://voyager.jpl.nasa.gov/spacecraft/index.h tml

30. Discussion Questions If we were to send another Voyager or Arecibo message, what would you include? – Instruments? – Music? – Videos? – Sounds? – Information?