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Our Unique Planet * With notes provided by David McDonald-Christa McAuliffe Planetarium

Our Unique Planet * With notes provided by David McDonald-Christa McAuliffe Planetarium. http://www.d21c.com/AAALynx/CB/pl/earth.jpg. What is the most unique characteristic of the Earth?. The presence and diversity of life. What factors allow this diversity?. Habitable Zone (HZ).

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Our Unique Planet * With notes provided by David McDonald-Christa McAuliffe Planetarium

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  1. Our Unique Planet* With notes provided by David McDonald-Christa McAuliffe Planetarium http://www.d21c.com/AAALynx/CB/pl/earth.jpg

  2. What is the most unique characteristic of the Earth? • The presence and diversity of life What factors allow this diversity?

  3. Habitable Zone (HZ) • The distance from the star where the average temperature of the planet allows liquid water to exist. http://www.mallorcaweb.net/masm/Planetas/nuevosplanetas.jpg

  4. Important Living Parameters For a Nice Home Planet

  5. 1. Number of stars in a planetary system • More than one star would likely cause unpleasant tidal effects (erode mountains, cover the earth) • Greater than 50% of stars are in multiple star systems. http://www.donorahog.org/pictures/NovaScotia4%20-%20Lobster%20boats%20at%20Halls%20Harbor%20on%20Bay%20of%20Funday%20at%20low%20tide.jpg • http://www.vredefortstructure.org/images/binary_starsystems_beta_lyraesml.jpg

  6. 2. Age of Star • The star needs to be in a stable burning phase for constant radiation and luminosity. http://helios.augustana.edu/~lc/sunxray.gif http://www.highwaygirl.com/hwg/images/star.jpg http://www.pd.astro.it/education/PlanetV/planetarium/icons/EQUI.GIF

  7. 3. Star Birth Date • Very long ago planets would not contain enough heavy elements. (need supernova for fusion of elements heavier than iron) http://www.atomicarchive.com/Fusion/Images/fusion.jpg

  8. 4. Star distance from the center of the home galaxy • If too close stellar density and radiation may be too great. • If the star is too far away, stellar density may not be great enough and heavy elements may be too rare to make rocky planets. http://www.knowledgerush.com/wiki_image/a/a6/Milky.way.arp.250pix.jpg

  9. 5. Mass of Parent Star • Too great and luminosity/radiation would change too quickly and the star would burn too rapidly/die quickly (Blue Giants). • Too much less and the habitable zone would need to be too close to the star-causing tidal forces to disrupt the rotational period (faster planetary day) and UV radiation may be too little for plant photosynthesis.

  10. 6. Parent Star Color • If too much more red or blue, photosynthesis response would be insufficient (plants wouldn't be able to properly photosynthesize -make their own food) http://www.homestead-farm.net/art/kidsArt/photosynthesis-color.jpg

  11. 7. Gravity of Planet • If gravity were stronger, the atmosphere would retain too much ammonia (NH3) and methane (CH4). • If gravity were weaker, the atmosphere would loose too much water vapor (H2O). http://static.howstuffworks.com/gif/hot-air-balloon-atmosphere.jpg http://teachertech.rice.edu/Participants/louviere/Images/profile.gif

  12. 8. Distance From Parent Star • Too great= too cool for stable water cycle • Too close= too hot for stable water cycle • This is the main aspect of Habitable Zone http://ag.arizona.edu/extension/riparian/images/ch3_hydro-cycle.jpg

  13. 9. Axial Tilt • If too much greater - the surface temperature differences would be too great. Ice and water vapor would travel to the poles, no water anywhere else. • If much less - the habitable zone would shrink in size (think narrow band around equator) http://www.learner.org/jnorth/images/imageshtml/earth-tilt.gif

  14. 10. Rotation Period • If days (rotation period) were longer the diurnal temperature differences would be too great (temperature between night and day). • If days were shorter, atmospheric wind speed would be too great. (due to pressure differences caused by different temperature air masses) http://www.physicalgeography.net/fundamentals/images/heatingwind.GIF http://old.grotte-de-han.be/expo/effetserre.jpg

  15. 11. Gravitational Interaction With a Moon • If the gravitational attraction were much stronger, than tidal effects on oceans, and rotational period would be too great. • Also effect climate and weather patterns due to increased spin http://www.esru.strath.ac.uk/EandE/Web_sites/01-02/RE_info/Tidal%20power%20files/image002.jpg

  16. 12. Magnetic Field • If stronger= severe electromagnetic storm • If Weaker= Inadequate protection from hard stellar radiation (solar wind) http://www.instituteforinquiry.org/inquiries/graphics/electrostorm.jpg

  17. 13. Thickness of Crust • If Thicker= More oxygen in crust. • If Thinner= More volcanic and tectonic plate activity. http://www.pacificislandtravel.com/nature_gallery/volcanoes2.gif http://geography.sierra.cc.ca.us/Booth/Physical/chp13_earth/crust_composition.gif

  18. 14. Albedo (reflected light ratio) • If greater amounts of light reflected= runaway ice age would develop. • If lesser amounts of light were reflected= runaway greenhouse effect. http://www.ronayres.com/images/glacier.jpg http://staffwww.fullcoll.edu/tmorris/elements_of_ecology/images/greenhouse_effect.jpg

  19. 15. Carbon Dioxide and Water Vapor Levels in the Atmosphere • If greater amounts= runaway greenhouse effect. • If lesser amounts= insufficient greenhouse effect. http://www.n-ergise.net/cnt/txt/40/1/greenhouse_effect.gif

  20. 16. Ozone Level in Atmosphere • If greater amounts of ozone= surface temperatures too low. • If less amounts of ozone= surface temperatures too high and too much UV radiation at surface. http://www.epcc.pref.osaka.jp/apec/eng/earth/ozone_layer_depletion/image/zu_g01.gif

  21. 17. Oxygen to Nitrogen Ratio in Atmosphere • Not enough oxygen= problems with respiration http://www.bbc.co.uk/schools/gcsebitesize/img/gcsechem_47.gif

  22. 18. Atmospheric Electric Discharge Rate http://www.takegreatpictures.com/content/images/1_3lighting_bolts.jpg • If Greater= too much fire destruction. • If Less= too little nitrogen would be fixed in atmosphere. http://www.scienceclarified.com/images/uesc_07_img0396.jpg

  23. 19. Quantity of Oxygen in Atmosphere • Greater= Plants and hydrocarbons would burn too easily. • Less= Advanced air breathing life forms would have too little for good function http://www.biblehelp.org/images/forest%20fire.jpg http://www.uic.edu/classes/bios/bios100/lecturesf04am/humrespsys_1.gif

  24. 20. Seismic Activity • Greater= destruction of life forms • Less= nutrients on ocean floors (from river runoff) would not be recycled by tectonic uplift. http://rst.gsfc.nasa.gov/Sect2/platespread.jpg

  25. Think About This…… • In 1999 Hubble space telescope indicated 125 billion galaxies. • Times that by a factor of 8 =1 trillion (1012) galaxies • There are approximately 100 billion stars per galaxy (1011) • (1011) stars x (1012) galaxies = 1022 stars in the universe

  26. Probability • If we consider (on average) a 1% chance of each of the twenty previously mentioned factors occurring favorable to life, that is…. • One chance in 1040 • Compared to “only” 1022 stars in the Universe • Therefore… we have a pretty unique home 

  27. Now Our Earth…. • 1. Temperature – • From the sun • Earths core/tectonics • 0-1000C needed for most life

  28. Factors that can influence Earths Temperature: • 1. Orbit (how fast we go around the sun)- faster/slower- effect length of our year • 2. Rotation- faster/slower- effect length of our days and nights • 3. Moon- stabilizes our spin (rotation) • 4. Tilt- effect our seasons • 5. Ocean Water- stabilizes temperature (heating/cooling air masses) • 6. Atmosphere- allows for a greenhouse effect (yes we need some)

  29. Suns Energy • 1. Visible light- • Temperature/Photosynthesis – release of oxygen from methane, ammonia and hydrogen • 2. Energy for life

  30. Moon • 1. Spin • Moon’s gravity helps stabilize Earths rotation (spin). Without it winds would be 500mph, climate would be unstable, great temperature differences. • 2. Tides • If the moon were closer we would have too great of tides • Erode mountains, cover the earth with water http://10.48.0.4/cgi-bin/overmain?args=d29ya3N0YXRpb249MTAuNDYuOC44OSZ1cmw9YUhSMGNEb3ZMMnBsWm1aeVpYbHJhWE5vYm1WeUxtTnZiUzlwYldGblpYTXZablZzYkY5dGIyOXVYMnhoY21kbExtcHdadz09JnByb2ZpbGU9SGlnaCZ1c2VyPVdPUkxEXEtTSU1QU09OJm9sPTAmcmE9MCZyYXRpbmdzPWEvbg==

  31. http://www.georgefcram.com/education/gr13.jpg Tilt • Responsible for Earths seasons • If too great, water vapor would move to poles (like Mars), no water anywhere else. • Cause bulges at the equator • Changes rotation period

  32. Liquid Water Responsible for: 1. weather patterns 2. clouds 3. coriolis effect 4. warm and cool water to keep oceans liquid The temperature of our planet allows for liquid water • Too hot- water vapor • Too cold- ice http://www.bom.gov.au/lam/climate/levelthree/analclim/imagesm/glbwnd.jpg

  33. Our Atmosphere • 1. 21% oxygen- photosynthesis • 2. Ozone protection- UV radiation • 3. Currents- transport oxygen and waste • 4. Burns meteors, blocks other radiation (ex- gamma rays, x-rays) • 5. Magnetosphere- (created because of iron core and mantel) blocks solar wind • 6. Greenhouse effect- keeps temperatures warm enough for life

  34. Size and Mass of Earth • Iron/Nickel core • Creates magnetosphere • Gravity • Allows survival • Holds atmosphere

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