1. Invent an Alien…

2. Define: EXOPLANET A planet that orbits a star other than our own sun A planet that orbits a star other than our own sun First one discovered in? First one discovered in? 1992 1992 How many have we discovered so far? How many have we discovered so far? 228 228

3. Plan for today Look at a couple of example of exoplanets Look at a couple of example of exoplanets Invent an Alien! Invent an Alien! Roll dice to determine the planet your alien lives on Roll dice to determine the planet your alien lives on Design the alien Design the alien Include a “smart part” – How does your alien get around? Include a “smart part” – How does your alien get around? Include a “smart action” – What (or how) does it eat? Include a “smart action” – What (or how) does it eat? We’ll look at some examples before we invent the alien. We’ll look at some examples before we invent the alien.

4. Exoplanets http://www.astronomy.com/asy/default.aspx?c=a&id=3105 http://en.wikipedia.org/wiki/2M1207b First picture of one (maybe) taken in April 2004 First picture of one (maybe) taken in April 2004 In orbit around brown dwarf 2M1207A In orbit around brown dwarf 2M1207A About 3 to 10 times the mass of Jupiter About 3 to 10 times the mass of Jupiter Takes about 1500 years to orbit its sun Takes about 1500 years to orbit its sun Brown dwarf Planet?

5. Nov 2008 announcements http://hubblesite.org/newscenter/archive/releases/2008/39/

6. http://planetquest.jpl.nasa.gov/news/hotShots.cfm

7. We got lucky Most planets are too close to their sun, and their sun too bright, to allow us to take a picture Most planets are too close to their sun, and their sun too bright, to allow us to take a picture Scientists use a variety of techniques to detect a planet Scientists use a variety of techniques to detect a planet Right now the techniques available work best for large planets that are close to their sun Right now the techniques available work best for large planets that are close to their sun

8. Light Light, like sound, can be broken up into unique frequencies (colors) Light, like sound, can be broken up into unique frequencies (colors) http://en.wikipedia.org/wiki/Image:Light_dispersion_conceptual_waves.gif

9. Detecting the wobble When an object orbits another object, they actually both orbit a common “center of mass”. When an object orbits another object, they actually both orbit a common “center of mass”.

10. We can detect that wobble Change in frequency (of sound or light) of a moving object called the “Doppler Effect” Change in frequency (of sound or light) of a moving object called the “Doppler Effect” for example a police car with siren driving by for example a police car with siren driving by And there are other techniques that can be used too And there are other techniques that can be used too

11. Doppler effect

12. Artist impressions of exoplanets It will be a long time before we can take a direct picture of an exoplanet It will be a long time before we can take a direct picture of an exoplanet We really don’t know what the planets look like We really don’t know what the planets look like We can make educated guesses We can make educated guesses

13. http://www.spitzer.caltech.edu/Media/releases/ssc2005-10/ssc2005-10c.shtml Compared to our own solar system's asteroid belt, this one is larger and closer to its star -- it is 25 times as massive, and lies just inside an orbit equivalent to that of Venus. HD 69830 d is an exoplanet planet orbiting the orange dwarf star HD 69830 (located 41 light years) every 197 days. It is the outermost known planet in its planetary system and possibly lies within its habitable zone. The system includes what is believed to be an asteroid belt.

14. Planet OGLE-2005-BLG-390Lb. Its star is most likely a red dwarf. It’s orbit is 2 to 4 times the size of Earth’s, meaning it gets little energy from its sun. Therefore the surface temperature is estimated as -220C (-364F)

15. Enough about planets, how about the aliens that live on them? OK, we don’t know what might live there… OK, we don’t know what might live there… Next 4 pictures and descriptions are from the following two books: Next 4 pictures and descriptions are from the following two books: Barlowe’s Guide to Extraterrestrials by Wayne Douglas Barlowe. Barlowe’s Guide to Extraterrestrials by Wayne Douglas Barlowe. The ALIEN Life of Wayne Barlowe by Wayne Douglas Barlowe. The ALIEN Life of Wayne Barlowe by Wayne Douglas Barlowe.

16. http://www.waynebarlowe.com/

20. Life on Earth can seem pretty unusual too… Thelepus setosus, up to 1 foot (30 cm), tentacles up to 3 feet (0.9 meters) long. Corkscrew gills and grooved feeding tentacles splay from a spaghetti worm, one of the many thousands of worm species that live at sea. This reef dweller protects its six-inch (15 centimeters) body in a sand-and-mucus tube while its appendages drift, snagging detritus and distracting foes. http://www7.national geographic.com/ng m/0702/feature4/gall ery1.html

21. Convolutriloba longifissura, 0.08-0.12 in (0.2-0.3 cm). An acoel is a tiny flatworm without a gut. Denizen of stony shallows, photosynthetic algae in its skin help nourish it. http://www7.national geographic.com/ng m/0702/feature4/gall ery1.html

22. Chaetopterus variopedatus, up to 9.8 in (25 cm) long The intricate parchment worm, this one about five inches (13 centimeters) long, is typically well-hidden in a U-shaped tube in the sand—through which it pumps water using paddles at the center of the body. Edible bits are caught and balled up in sticky mucus bags that form below the rectangular head. When disturbed, this remarkable animal can expel bioluminescent mucus. http://www7.national geographic.com/ng m/0702/feature4/gall ery1.html

24. Postscript

25. Habitable zones http://en.wikipedia.org/wiki/Habitable_zone (habitable for life as we know it, i.e. where the temperature where water is a liquid)

26. Scientific American Magazine http://www.sciam.com/article.cfm?id=the-color-of-plants-on-other-worlds April 2008 Issue

27. On a world with a (smaller) cooler, dim star the plants might need to be black On a world with a (smaller) cooler, dim star the plants might need to be black

28. Planets around very young small stars would be bathed in ultraviolet light, making the only safe place underwater Planets around very young small stars would be bathed in ultraviolet light, making the only safe place underwater