1. Extraterrestrial Life Antígona Segura Peralta Penn State University, College of Earth and Mineral Sciences Penn State Astrobiology Research Center

2. They do exist!

3. Astrobiology Astrobiology is the science that studies the origin, evolution and distribution of life in the Universe

4. The origin of life on Earth 4 billion years ago

5. What does life need?  Raw materials: hydrogen, carbon, oxygen, nitrogen and minerals like iron and sulfur.  Energy: Sun, volcanoes  A liquid: Water

6. Planets, the perfect place  They contain raw materials  Energy sources  They can have liquid water

7. Our Solar System Mercury Venus EarthMars Jupiter Saturn Uranus Neptune Pluto

8. The terrestrial planets Very near the Sun Very hot because its atmosphere No atmosphere, cold but… Mercury Venus Mars

9. Mars today

10. Mars, an interesting past Ancient volcanoes Ancient rivers?

11. Mars might be like this

12. Little martian?

13. The giant planets Jupiter Saturn Uranus Neptune

14. Europa, Jupiter’s moon

15. Europa

17. Milky Way 100 billion of stars!

18. Where the stars are born Molecular cloud

19. Formation of stars and planets Beta Pictoris, a newborn star

20. Formation of stars and planets Beta Pictoris disk (artist conception)

21. Extrasolar planets

22. The life of the stars Yellow dwarf 10 billion years Red Giant Panetary nebula and white dwarf

23. The life of the stars Blue giants Supernova Supernova remmanent and neutron star 100 million years

24. A habitable world Characteristics:  Distance from its star, not too far, not too close  Size, not too big, not too small  Atmosphere to keep the planet warm and water liquid  Water

25. Biomarkers Those features whose presence or abundance can be attributed to life

26. Signatures of life?

27. Small things can make big changes Cyanobacteria

28. How to find a planet? Problem: The stars emit light (a lot!) and planets doesn’t, they just reflect the light from their parent star. How to solve it?  Cover the star!!!!  Measure the effects of the planets on the stars:  Stars wobble because of the planets  Stars dim when a planet crosses in fron of them

29. Looking for habitable worlds Kepler:  Look for terrestrial planets around 100,000 stars.  Launch on 2006.

30. Looking for habitable worlds Terrestrial Planet Finder (TPF):  Look for terrestrial planets around 100 nearby stars.  Analyze the planets to detect those that may be habitable  Launching on 2012-2015

31. Looking for habitable worlds Eddington:  Looking for planets bigger than Mars around 500,000 stars.  Launching on 2008.

32. Darwin:  Look for terrestrial planets around 1,000.  Launching after 2014. Looking for habitable worlds

33. Intelligent life? Arecibo Antenna, Puerto Rico Globular Cluster M13

34. The Pioneer mesage

35. Voyager

36. SETI: Search for extraterrestrial life Allen array Project Phoenix

37. A habitable world