2. Bellringer: Draw our solar system. Label the planets. Make it colorful. Keep it in your notebook. Saturn, Jupiter, Uranus Neptune Earth, Mars, Venus mercury

3. Earth’s Position in Space What is Earth’s position within the hierarchy of the universe?

4. Your Cosmic address Suppose you had an alien friend who lived across the universe billions of light years away. Suppose they wanted to mail you a letter through some sort of intergalactic postman. What address would you give them? Brainstorm your address with your neighbor. In your notebook, begin writing the address. Start with: Your name, Street, City, State, Country, Continent, hemisphere and.....

5. Planet: Earth

6. Solar System (3 rd planet from Sun)

7. Milky Way Galaxy (the Orion Arm) a galaxy contains a large number of stars. Ours contains at least 400 billion stars.

8. Our Milky Way galaxy is about 13 billion years old. Our Sun is just one of perhaps 100 billion stars that make up the Milky Way. The Milky Way Galaxy A galaxy is a large group of stars, gas and dust held together by gravity, The Milky Way is a great disk made of stars orbiting a central point in the disk. The Milky Way Galaxy

9. The Shape of the Milky Way The Milky Way consists of a nuclear bulge in the center of a disk. The disk and bulge are surrounded by a spherical region called the halo. (not to scale) The Milky Way Galaxy

10. Other Galaxies in the Universe Our galaxy is just one of billions of galaxies in the universe. Other Galaxies in the Universe In 1924, Edwin Hubble discovered the Andromeda galaxy. It is our nearest neighbor. It is speeding towards us and will one day collide into us!

11. Group clump of 50 or less galaxies, our clump has around a dozen galaxies

12. Supercluster thousands of clusters (groups) of galaxies, ours is called the Virgo Supercluster

13. Groups and Clusters of Galaxies Most galaxies are located in groups, rather than being spread uniformly throughout the universe. Other Galaxies in the Universe –The Milky Way belongs to a small cluster of galaxies called the Local Group which is roughly 2 million ly in diameter. –There are about 35 known members including the Milky Way and Andromeda Galaxies, but most of are dwarf ellipticals. A supercluster is an even larger cluster of.galaxies.

14. Universe contains a large number of superclusters scattered across space in a foam like structure. Empty spaces called voids are within the structure.

15. Your cosmic address Now that you have this additional information, finish your cosmic address. Mrs. Chapel will come around to check your work.

16. Earth’s Motion through Space How is Earth’s motion related to the origin of the galaxy and its solar system?

17. The Expanding Universe In 1929, Edwin Hubble, by measuring the redshifts and distances of many galaxies, found that the farther away from Earth a galaxy is, the faster it is moving away. Other Galaxies in the Universe The universe is expanding, still moving outward! Because it takes the light from very distant galaxies so long to reach Earth, when astronomers observe these galaxies, they are looking back in time.

18. The Origin of Our Expanding Universe a. The Big Bang Theory –The theory that the universe began as a point and has been expanding ever since Notice how the 3 yellow galaxies in each model are moving apart? en.wikipedia.org

19. Models of the Universe The fact that the universe is expanding implies that it had a beginning. Cosmology –The Big Bang theory is the theory that the universe began as a point and has been expanding ever since. –The steady-state theory proposes that the universe is the same as it has always been and new matter is being created as the universe expands maintaining its density. The evidence from observational tests weighs in favor of the Big Bang.

20. The Big Bang Model Three possible outcomes for the universe include: Cosmology –an open universe, in which the expansion will never stop –a closed universe, in which the expansion will stop and turn into a contraction –a flat universe, in which the expansion will slow to a halt in time—but it will never contract

21. The Origin of the Milky Way The Origin of the Milky Way b. Astronomers hypothesize that the galaxy began as… A rotating, spherical cloud in space … A rotating, spherical cloud in space … Our solar system continues to orbit the center of the Milky Way because… it developed in the plane of the disk around the nuclear bulge (in the center) Our solar system continues to orbit the center of the Milky Way because… it developed in the plane of the disk around the nuclear bulge (in the center) It is hypothesized that the Milky Way began as a spherical cloud of gas that eventually collapsed into a disk. http://www.google.com/imgres?imgurl=http://casswww.ucsd.edu/archive/public/tutorial/images/mw.jpg&imgrefurl=http://casswww.ucsd.edu/archive/public/tutorial/MW.html&usg=__

22. The Shape of the Milky Way Spiral Arms The Milky Way Galaxy

23. Also, most new stars form in the arms because of the amount of dust and gas located there. The center consisting of the bulge and halo are made of old stars and leftover heavy elements The middle part of the galaxy is the oldest, where the oldest stars are found. Today we believe that there is a black hole at the center of our galaxy that we rotate around.

24. Our Milky Way galaxy is a spiral one and our solar system is located on one of its arms. It is estimated that our solar system has orbited the galaxy about 20 times in its 5 billion year existence. The Milky Way Galaxy

25. The Milky Way http://www.atlasoftheuniverse.com/ http://www.atlasoftheuniverse.com/ http://www.atlasoftheuniverse.com/

26. The Milky Way http://www.astropix.com/HTML/D_SUM_S/MILKYWAY.HTM http://www.astropix.com/HTML/D_SUM_S/MILKYWAY.HTM http://www.astropix.com/HTML/D_SUM_S/MILKYWAY.HTM

27. The Origin of the Solar System c. Our solar system began when… …a rotating, interstellar cloud - a nebula - collapsed (as a result of gravity) to form the Sun and planets …a rotating, interstellar cloud - a nebula - collapsed (as a result of gravity) to form the Sun and planets Earth orbits the Sun because … … it was located outside the center of the spinning nebula … it was located outside the center of the spinning nebula Video Video http://solar-flux.forumandco.com/t349-moa-2008-blg-310lb-planet-in-the-galactic-bulge

28. The Eagle Nebula http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-astro-nebula.html A solar nebula is… A disk of dust and gas that can form a star

29. Star formation has NEVER been observed! (just hypothesized!)

30. Lesson 2 Kepler’s Laws and Earth’s Orbit

31. Bellringer Go to mindmup.com Create a mind map of either Earth’s hierarchy in space or the Big Bang Theory (event) Share or save to onedrive. Can share to shana.chapel@apps. Cabarrus.k12.nc.us shana.chapel@apps. Cabarrus.k12.nc.us

32. Think About It… How would Earth be different if its orbit was more oval than circular?

33. Focus Question How do Kepler’s laws describe Earth’s orbit?

34. 3. Kepler’s Laws (Introduction)… Johannes Kepler, working with data painstakingly collected by Tycho Brahe (from 1576-1601) without the aid of a telescope, developed three laws which described the motion of the planets across the sky. Unless otherwise noted, the info on the slides on Kepler’s laws was taken from the following website: http://hyperphysics.phy-astr.gsu.edu/hbase/kepler.html http://hyperphysics.phy-astr.gsu.edu/hbase/kepler.html http://www.nmspacemuseum.org/halloffame/images.php?image_id=131

35. a. Kepler’s First Law… a. The Law of Orbits: All planets move in elliptical orbits, with the sun at one focus.Law of Orbits i. An ellipse is … an oval shape centered on two points instead of a single point. ii. The orbital period of a planet is … the length of time it takes for it to travel a complete orbit around the sun. (a year!)

36. Background…Orbit Eccentricity The eccentricity of an ellipse can be defined as the ratio of the distance between the foci to the major axis of the ellipse. The more eccentric an orbit, the more of an oval it is. The eccentricity of an ellipse can be defined as the ratio of the distance between the foci to the major axis of the ellipse. The more eccentric an orbit, the more of an oval it is. The eccentricity is zero for a circle. The eccentricity is zero for a circle. Of the planetary orbits, only Pluto has a large eccentricity. Of the planetary orbits, only Pluto has a large eccentricity. http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=175

37. Examples of Ellipse Eccentricity Planetary orbit eccentricities Mercury.206 Venus.0068 Earth.0167 Mars.0934 Jupiter.0485 Saturn.0556 Uranus.0472 Neptune.0086 Pluto.25

38. b. Kepler’s Second Law… b. The Law of Areas: A line that connects a planet to the sun sweeps out equal areas in equal times.Law of Areas i. Draw this! ii. When the planet is closer to the sun, it moves faster, sweeping through a longer path in a given time. (to conserve angular momentum) http://www.mathacademy.com/pr/prime/articles/kepler/index.asp

39. c. Kepler’s Third Law… c. The Law of Periods: The square of the orbital period of any planet is proportional to the cube of the semimajor axis of its orbit.The Law of Periods i.P² = a³ (P = orbital period = unit of time in Earth yrs, a = length of the semimajor axis) ii.If you know the distance of a planet to the Sun, you would be able to figure out its… orbital period.

40. 4. Barycenter and Earth’s Orbit… Barycenter is … Barycenter is …the center of mass between a planet and the Sun. a. The law of universal gravitation states that… every pair of bodies in the universe attracts each other with a force every pair of bodies in the universe attracts each other with a force proportional to the product of their masses and proportional to the product of their masses and inversely proportional to the square of the distance between them. inversely proportional to the square of the distance between them.

41. Bellringer Obtain 4 post-it notes Label them winter, spring, summer, and fall. List everything that you know about these seasons and stick them to the board at the back of the room. After you finish, answer the notecard questions hanging around the room.

42. The Equation

43. 4. Barycenter and Earth’s Orbit… b. A planet, such as Earth, actually orbits… its barycenter with the Sun c. The Sun orbits … the barycenter of the solar system. (It is NOT stationary in the sky as planets orbit it.) http://www.barewalls.com/pv-605547_Barycenter-Diagram.html d. Draw this! See next slide.

44. Modeling Barycenter –http://spaceplace.nasa.gov/barycenter/http://spaceplace.nasa.gov/barycenter/

45. Lesson 3 Earth’s Rotation Day and Night Earth’s Slightly Squashed Shape

46. Think About It… How would Earth’s day be different if it did not rotate on its axis?

47. Focus Questions… What causes the day and night cycle? What motion and force causes Earth’s slightly squished shape?

48. 5. Earth’s Rotation Causes Day and Night… 5. Day and night are caused by… … the rotation of Earth on its axis - spinning towards and away from the Sun. … the rotation of Earth on its axis - spinning towards and away from the Sun. a. Earth’s axis is… o … the imaginary line that goes through the N and S poles. b. We know that Earth is spinning on its axis because we see …  … the sun rise in the east & set in the west.

49. Think About It… Why are there 24 hours in a day? Earth spins… 15 degrees each hour There are 360 degrees in a circle (the circumference of Earth). 360 divided by 15 is 24 so there are 24 hours in a day! http://huntingtonastro.wikispaces.com/file/view/earth-rotation.png/199559520/earth-rotation.png

50. Still Thinking About It… The exact amount of time it takes Earth to spin one time on its axis is… The exact amount of time it takes Earth to spin one time on its axis is… 23.9345 hours (Write this in the margin!) 23.9345 hours (Write this in the margin!) If an Earth day was 5832.5 hours long (like that of Venus!) then… If an Earth day was 5832.5 hours long (like that of Venus!) then… It would take 243 days for Earth to spin one time on its axis! It would take 243 days for Earth to spin one time on its axis! Our day and night would be much longer! (And it would get really hot and really cold!) Our day and night would be much longer! (And it would get really hot and really cold!)

51. Sunrise and Sunset c. What is actually happening when we see the Sun rise and set? o At sunrise, we spin towards the Sun and see it “rise” and at sunset, we spin away from the Sun, we see it “set.” d. Draw this concept! http://curious.astro.cornell.edu/images/pathofsun_40deg.jpg

52. 6. Earth’s Rotation Causes Its Slightly-squished Shape… a. What motion causes Earth to take the shape of an oblate spheroid? Earth’s rotation b. What force causes the Earth’s mass to move outward from its center at the equator as Earth rotates on its axis? centripetal force

53. Earth’s Rotation and Its Shape… http://www.cleonis.nl/physics/phys256/equatorial_bulge.php

54. 6. Earth’s Rotation Causes Its Slightly-squished Shape… c. There is a slight bulging at the equator and a slight squishing at the poles. d. This causes the circumference at the equator to be slightly larger than that of the poles.

55. Earth’s Rotation and Its Shape… Simulation: http://www.cleonis.nl/physics/phys256/equatorial_bulge.phphttp://www.cleonis.nl/physics/phys256/equatorial_bulge.php e. Draw this  Notice the equatorial diameter is 42 km more than the polar diameter!

56. Lesson 4 The Seasons

57. Think About It… During which month is Earth closest to the Sun?

58. Focus Question (and Answer!)… 7. What causes the seasons? The tilt of the Earth on its axis as it revolves around (orbits) the Sun.

59. 7. Earth’s Orbit and Seasons… a. The ecliptic is… …the plane on which Earth orbits around the Sun …the plane on which Earth orbits around the Sun http://en.wikipedia.org/wiki/Ecliptic

60. 7. Earth’s Orbit and Seasons… b. The tilt of Earth’s axis relative to the ecliptic is 23.5 degrees. http://republicanredefined.com/2010/03/02/chile-quake-shifted-earths-axis-and-made-days-shorter/

61. 7c. Draw The Seasons! P. 760 http://www.exploratorium.edu/ancientobs/chaco/HTML/TG-shadows.html

62. 7. Earth’s Orbit and the Seasons! d. What causes summer in the northern and southern hemispheres? when it is tilted toward the Sun during Earth’s orbit when it is tilted toward the Sun during Earth’s orbit d. What causes winter in the northern and southern hemispheres? when it is tilted away from the Sun during Earth’s orbit when it is tilted away from the Sun during Earth’s orbit

63. 7. Earth’s Orbit and Seasons… e. The seasons in the northern and southern hemispheres are opposite each other because… When one hemisphere is tilted towards the Sun, the other is tilted away from the Sun When one hemisphere is tilted towards the Sun, the other is tilted away from the Sun

64. Seasons… f. Earth is closest to the Sun during our… Winter! (In January) And farthest from the Sun during the Antarctic winter (which makes it tough on the penguins!) http://www.onlytoptens.com/wp-content/uploads/2011/08/top-10-documentaries-march-of-the-penguins.jpg

65. Lesson 5 Changes in The Seasons – Precession and Nutation

66. Think About It… What would happen to the average temperatures during our winter if Earth was tilted MORE on its axis ?

67. Focus Question… What circumstances can bring about a change in the seasons?

68. 8. Precession 8. Precession is… the wobble in Earth’s rotational axis. a. One full cycle of precession takes… 26,000 years! b. The force that causes precession is… the sideways pull of the Moon’s on the Earth. (See next slide)

69. The Moon’s orbit is tilted 5° which over time pulls on Earth… http://earthsky.org/astronomy-essentials/what-is-the-ecliptic

70. 8. Precession… c. Our current north star is… Polaris In about 12,000 years, our new north star will be… Vega http://www.wwu.edu/skywise/a101_precession.html

71. A New North Star and Our Seasons… e.i. Winters in the N. hemisphere will be… in June, July, and August It will be colder here because Earth will be farthest from the Sun. e.ii.. Summers in the N. hemisphere will be… in December, January, and February It will be warmer here because Earth will be closest to the Sun.

72. A New North Star and Our Seasons… http://apollo.lsc.vsc.edu/classes/met130/notes/chapter16/precession.html d. Draw this!

73. 9. Nutation… Nutation is… … a change in the angle of tilt of Earth’s axis a. Present tilt of Earth’s axis is 23.5°. b. The tilt can vary from 22.1° to 24.5 °. http://www.cgrer.uiowa.edu/people/carmichael/atmos_course/ATMOS_PROJ_99/bilskemp/natural_variability.html

74. 9. Nutation… c.i. If the angle of tilt decreased… there would be less of a temperature difference between seasons. c.ii. If the angle of the tilt of Earth’s axis increased … there would be more of a temperature difference between seasons. http://www.cgrer.uiowa.edu/people/carmichael/atmos_course/ATMOS_PROJ_99/bilskemp/natural_variability.html

75. d. Draw Nutation p. 373

76. Lesson 6 Tides

77. Think About It… Tides Lesson How would Earth’s oceans be affected if Earth did not have a moon?

78. Focus Question… What forces and heavenly bodies cause the tides?

79. Tides… 10. Tides are caused by… the gravitational attraction among Earth, the Moon, and the Sun. (Write next to Q #10.) a. Tides are… the periodic rise and fall of sea level. i. High tide… Highest level to which the water rises ii. Low tide… lowest level of the water

80. Tides: Bay of Fundy… http://www.srh.noaa.gov/jetstream/ocean/fundy_max.htm http://www.amusingplanet.com/2012/03/tides-at-bay-of-fundy.html Low Tide High Tide

81. The Cause of Tides… b. What motion causes the tides? Earth’s rotation on it’s axis c. What forces causes the tides? gravitational attraction of the Moon and the Sun that “pulls” ocean water toward them and centrifugal force that causes ocean water on the opposite side of Earth to swish away These forces generate tidal bulges on opposite sides of Earth. d. The times of tides vary each day as the moon orbits the Earth (every 28 days)

82. 7e. Draw the Tides… (as seen from above) http://mail.colonial.net/~hkaiter/Moon_Phases_Tides.html Tide Simulation: http://astro.unl.edu/classaction/animations/lunarcycles/tidesim.html http://astro.unl.edu/classaction/animations/lunarcycles/tidesim.html

83. Lesson 7 The Sun’s Energy

84. Think About It… Is it possible to make electricity by using the same process that powers the Sun?

85. Focus Question… What process powers the Sun and what forms of Energy does that process produce?

86. A Little Bit About the Sun… How many Earths could be lined up edge to edge to fit across the Sun? 109 The Sun makes up… 99% of the mass of the solar system! A pair of dice with the density of the Sun… would weigh 2 pounds! The solar interior is made of… … plasma (one of the 4 states of matter)

87. The Sun’s Atmosphere… The Sun’s atmosphere consists of… Photosphere… Photosphere… the lowest layer the lowest layer 400 km thick 400 km thick Hot! (5800 K) Hot! (5800 K) the visible surface of the Sun the visible surface of the Sun http://www.solarviews.com/images/VSS00031.jpg

88. The Sun’s Atmosphere… The Sun’s atmosphere consists of… Chromosphere… Chromosphere… Above the photosphere Above the photosphere 2500 km thick 2500 km thick Very hot! (30,000 K) Very hot! (30,000 K)

89. The Sun’s Atmosphere… The Sun’s atmosphere consists of… Corona… Corona… Extends several million km from the top of the chromosphere Extends several million km from the top of the chromosphere Very low density – only visible during an eclipse Very low density – only visible during an eclipse Extremely hot! (1 to 2 million K) Extremely hot! (1 to 2 million K)

90. 11. Fusion (or Fission?) a. Fusion is… –the combining of hydrogen atoms into a helium atom.

91. 5. Fusion… b. Fusion occurs… in the stars! (our Sun) in the stars! (our Sun) c.a. During fusion, the two atoms that combine to form a helium atom are… Hydrogen atoms (deuterium and tritium) Hydrogen atoms (deuterium and tritium)

92. 5. Fusion… c.b. The mass that is lost when two hydrogen nuclei combine to form helium … … gets converted into energy … gets converted into energy f. Albert Einstein’s theory of special relativity explains this! http://www.nobelprize.org/nobel_prizes/physics/laureates/1921/einstein-bio.html

93. Fusion and Electricity Production… “The power produced by a fusion reactor will be converted to electric energy or other goods like hydrogen or desalinised water. Neutrons produced in the D-T fusion process carry 4/5 of the energy. One or two fluids circulate in the blanket and in the diverter/FW to extract the energy and to provide stable operational temperature of the components. The fluids must flow at high velocity (often in conditions of turbulent flow) while structural materials, pipes, junctions must withstand neutron bombardment, corrosion/erosion, high operational temperature, high heat flux.” What??!! http://www.isfrt-erice.enea.it/Page2.htm

94. Fusion and Electricity Production…

95. China claims fusion reactor test a success Government hopes fusion provides clean, limitless energy source … “BEIJING - Scientists on Thursday carried out China's first successful test of an experimental fusion reactor, powered by the process that fuels the sun, a research institute spokeswoman said. China, the United States and other governments are pursuing fusion research in hopes that it could become a clean, potentially limitless energy source. Fusion produces little radioactive waste, unlike fission, which powers conventional nuclear reactors.” http://www.msnbc.msn.com/id/15043462/ updated 3:22 p.m. ET, Thurs., Sept. 28, 2006

96. 11d. Fusion Reaction – Draw this!

97. 11. Fission (or Fusion?) e. Fission is… –The splitting of heavy atoms into smaller, lighter atoms –We use this process to generate electricity in a nuclear power plant.

98. 11. Fusion (or Combustion?) f. Combustion is… –The burning of a fuel in the presence of oxygen to produce heat and light http://reich-chemistry.wikispaces.com/M.Higgins+And+D.Lazerev+Reaction+Wiki

99. 12. The Sun’s Energy… a. Electromagnetic radiation consists of … … electric and magnetic disturbances that travel through space as waves. b. Electromagnetic radiation includes… radio waves, microwaves, infrared energy, visible light, ultraviolet radiation, x-rays, and gamma rays c. The electromagnetic spectrum… Organizes the forms of EM energy d. Electromagnetic energy… …is classified by wavelength and… e. … moves at the speed of light

100. The Electromagnetic Spectrum… http://www.lbl.gov/MicroWorlds/ALSTool/EMSpec/EMSpec2.html e. This is the dangerous side!

101. Absorption of The Sun’s Energy by the Earth… f. Which gas in the atmosphere blocks harmful ultraviolet radiation from the sun? Ozone (O 3 ) Ozone (O 3 ) http://mmedia.pl/ozone-layer-diagram-for-kids

102. 13. Solar Wind and Earth’s Magnetic Field… a. Solar wind is… A supersonic plasma that flows outward from the corona at high speeds A supersonic plasma that flows outward from the corona at high speeds It consists of charged particles or ions It consists of charged particles or ions Solar wind bathes each planet in a flood of high-energy particles. (Which isn’t very good for us!) Solar wind bathes each planet in a flood of high-energy particles. (Which isn’t very good for us!) Next slide… Next slide…

103. Solar Wind

104. 13. Solar Wind and Earth’s Magnetic Field… b. Earth’s magnetic field protects us from the solar wind by… deflecting these particles and trapping them in two huge rings called the Van Allen belts deflecting these particles and trapping them in two huge rings called the Van Allen belts http://www.redorbit.com/education/reference_library/space_1/solar_system/2574610/van_allen_radiation_belt/

105. Earth’s Magnetic Field… c. Draw this!

106. 13. Solar Wind and Earth’s Magnetic Field… d. The auroras are created when… … high-energy particles in the Van Allen belts collide with gases in Earth’s atmosphere which give off light … high-energy particles in the Van Allen belts collide with gases in Earth’s atmosphere which give off light See next slide… See next slide…

107. The Auroras… http://www.lovethesepics.com/2011/02/24-amazing-auroras-aurora-borealis-aurora-australis/

108. Lesson 8 Energy For Earth…

109. Think About It… What would happen to Earth if the Sun were turned off today?

110. Focus Question… How does the Sun’s energy warm Earth’s surface and atmosphere?

111. 14. Energy For Earth… http://virtualskies.arc.nasa.gov/weather/images/2b1.png a. Radiation is … the transfer of energy through space by visible light, ultraviolet radiation, and other electro- magnetic waves

112. What Happens to the Sun’s Energy? http://www.physicalgeography.net/fundamentals/images/cascade.GIF

113. 14. Energy For Earth… a.i. The Sun’s energy reaches Earth by the process of radiation. a.ii. About 50 % of the Sun’s energy is absorbed by Earth’s surface. http://ossfoundation.us/projects/environment/global-warming/earths-radiation-budget

114. Differential Heating… Differential Heating… a.iv. Which heats up and cools down more slowly – water or land? Water Water This is called differential heating. (Circle this term on your lesson!) This is called differential heating. (Circle this term on your lesson!) This is what moderates the climate in coastal areas. This is what moderates the climate in coastal areas.

115. Energy for Earth… a. Radiation the transfer of energy through space by visible light, ultraviolet radiation, and other electromagnetic waves Earth’s surface is warmed by the sun’s rays http://ossfoundation.us/projects/environment/global-warming/earths-radiation-budget

116. Energy for Earth… b. Conduction is… the transfer of energy that occurs when molecules collide i. The air molecules above Earth’s surface are warmed by the process of conduction. ii. Energy moves from your hand to your desk. Why?

117. Energy for Earth… c. Convection is… the transfer of energy by the flow of a heated substance i. Warm air rises. ii. When the warm air gets high enough, it cools and sinks. iii. This creates a convection current. http://avstop.com/ac/fig5-9.jpg

118. Energy For Earth… Copy the diagram your teacher draws on the board!

119. 15. Energy for Photosynthesis… a. During photosynthesis, solar energy is transformed into chemical energy. b. This occurs in plants, algae and some bacteria. c. For this to occur, there must be water, CO2, and sunlight. d. In plants, this occurs in chloroplasts. http://abhsscience.wikispaces.com/Photosynthesis+TD

120. Food From the Sun! http://wowk.images.worldnow.com/images/19108684_BG1.jpg