2. Bit of Administration …. Washburn ObservatoryWashburn Observatory –Wednesday, after dusk for a few hours ReadingReading –Chapter 24, Chapter 14 recommended Discussion SectionDiscussion Section –Web-lecture in advance of section 2 pts extra credit for evaluation2 pts extra credit for evaluation 3 pt extra credit quiz3 pt extra credit quiz responsible for materialresponsible for material

3. THE EXTRA-SOLAR PLANET PROJECT Phase 1: Last week’s quiz. Phase 2 : A Web-Lecture on Extra-Solar Planets. –Learn about extra-solar planets and have opportunity to earn 5 pts extra credit. 2 pts for evaluation questions 3 pts for success on quiz –Preparation for next week’s discussion sections (5/3-5/7). –Access: http://eteach.engr.wisc.edu/meibom/espp/index.html –Speed: 300 Kbps, 100 Kbps, and 37 Kbps. The hardware requirements for viewing the lecture are: –A computer with connection to the Internet. –Computer speakers or headphones. The software requirements for viewing the lecture are: –Windows Operating System. –Internet Explorer version 5.5 or later. –Power Point 2002 or later ("Power Point Animation plug-in"). Campus computer-labs: –http://www.doit.wisc.edu/computerlabs/index.asp –Bring headphones!

4. Asteroids, Comets, Meteors, and Pluto

5. Primordial Icy Planetesimals Fragmented Icy Planetesimals (KBOs) Rocky Planetesimals Icy Planetesimals Jupiter Forms Oort Cloud Kuiper Belt Sedna

6. Asteroids, Comets, Meteors, and Pluto Summary Summary Asteroids Asteroids Rocky Planetesimals Rocky Planetesimals Comets Comets Long - Period = Icy Planetesimals Long - Period = Icy Planetesimals Short - Period = Fragmented KBOs Short - Period = Fragmented KBOs Pluto, Sedna, Triton, Kuiper Belt Objects Pluto, Sedna, Triton, Kuiper Belt Objects Icy Planetesimals Icy Planetesimals Meteors Meteors Processed Iron and Stony Meteorites Processed Iron and Stony Meteorites Fragmented asteroids Fragmented asteroids Meteor Showers Meteor Showers Fragmented comets Fragmented comets Primitive Meteors = Rocky Planetesimals Primitive Meteors = Rocky Planetesimals

7. Asteroids, Comets, Meteors, and Pluto

8. Meteors Meteors Showers - debris of old comets Showers - debris of old comets Earth orbit Past Comet

9. Asteroids, Comets, Meteors, and Pluto Meteors Meteors Types - Processed Meteorites Types - Processed Meteorites Stony Meteorites Stony Meteorites 93% 93% Just like crust of Earth Just like crust of Earth Iron Meteorites Iron Meteorites 6 % 6 % Crystallization patterns => long cooling times Crystallization patterns => long cooling times

10. Asteroids, Comets, Meteors, and Pluto Meteors Meteors Types - Primitive Meteorites Types - Primitive Meteorites Stony, with trace of pure metallic flakes Stony, with trace of pure metallic flakes Carbonaceous chondrites Carbonaceous chondrites Carbon compounds, and even water Carbon compounds, and even water

11. Life in the Solar System Arguments for Life as High Probability Arguments for Life as High Probability Organic molecules form easily Organic molecules form easily Carbonaceous Chondrites Carbonaceous Chondrites Allende Meteorite 2/8/69, 1:05 AM Allende Meteorite 2/8/69, 1:05 AM Calcium-Aluminum Inclusions (CAIs) Chondrules (Amino Acids)

12. Life in the Solar System Arguments for Life Arguments for Life Organic molecules form easily Organic molecules form easily

13. Life in the Solar System Arguments for Life as High Probability Arguments for Life as High Probability Organic molecules form easily Organic molecules form easily Life occurred quickly on Earth - < 3.85 billion years Life occurred quickly on Earth - < 3.85 billion years 3.5 billion yr old Stromatolites (cyanobacteria)

14. Life in the Solar System Arguments for Life as High Probability Arguments for Life as High Probability Organic molecules form easily Organic molecules form easily Life occurred quickly on Earth - < 3.85 billion years Life occurred quickly on Earth - < 3.85 billion years 4.4 billion yr old zircon high oxygen isotope ratios cool water on Earth!

15. Life in the Solar System Arguments for Life as High Probability Arguments for Life as High Probability Organic molecules form easily Organic molecules form easily Life occurred quickly on Earth - < 3.85 billion years Life occurred quickly on Earth - < 3.85 billion years Life can exist in a wide range of conditions Life can exist in a wide range of conditions

16. Life in the Solar System Life on Mars ? Life on Mars ? Flowing water and warm conditions for ≈ 1 byr Flowing water and warm conditions for ≈ 1 byr Extensive volcanos Extensive volcanos Martian meteorites Martian meteorites ALH84001 ALH84001 magnetite crystals

17. Life in the Solar System Life on Mars ? Life on Mars ? Flowing water and warm conditions for ≈ 1 byr Flowing water and warm conditions for ≈ 1 byr Extensive volcanos Extensive volcanos Martian meteorites Martian meteorites

18. Life in the Solar System Life on Europa ? Life on Europa ? Icy crust Icy crust Tidal heating Tidal heating Liquid oceans Volcanic vents

19. Life in the Solar System Life on Europa Life on Europa Icy crust Icy crust Tidal heating Tidal heating Liquid oceans Volcanic vents