Transcript sun
Warm Up- Do this on the next blank page should be page 10 1) Think about your current location at this exact moment. If someone asked for your current location, how specific can you get in describing where you are to them? How general? 2) How do you think the universe formed? (come up with a theory/story/hypothesis!) How many universes are there? http://ed.ted.com/lessons/howmany-universes-are-there The most astounding fact about the universe • http://www.youtube.com/watch?v=9D05ej8ugU Your Universal Address • What is your address? • What about beyond the State?...Beyond the country?...Beyond the continent? Beyond the WORLD?! • Let’s figure it out Which is bigger? • Universe: all matter and energy, including the earth, the galaxies, and the contents of intergalactic space, regarded as a whole • Galaxy: groups of stars, dust, and gases held together by gravity • The universe is made of galaxies which are made of many stars. • Some stars have planetary systems similar to our solar system • Earth is satellite planet of one particular star: the SUN! Origins • How and when did the: – universe form? – solar system / Earth form? – Moon form? • What were early Earth conditions? How Do We Know? Origin of the Universe • Big Bang – occurred 15 billion years ago – http://www.youtube.com/watch?v=PV0ACIykx QI Building a Universe - A single dot of matter. http://rainbow.ldeo.columbia.edu/courses/v1001/7.html Building a Universe - Then……BANG!!!.......the universe was formed! http://rainbow.ldeo.columbia.edu/courses/v1001/7.html Edwin Hubble • Said: – Universe is still growing! Features of Our Solar System • Located in a spiral arm of the Milky Way Galaxy • Sun is at the center • 8 planets (and Pluto, which is no longer a planet!) • 101 known moons (satellites) • a tremendous number of asteroids – most orbit between Mars and Jupiter • millions of comets and meteorites • dust and gases Relative Sizes of the Sun and Planets Solar System Configuration Origin of Our Solar System Solar nebula theory cloud of gases and dust began to spin and then gravity pulled clumps of it together to form the sun and planets The Planets • Terrestrial Planets – – – – Jovian Planets Mercury Venus Earth Mars • Small and rocky – Pluto? Jupiter Saturn Uranus Neptune Large and made of gases like hydrogen and helium Heliocentric vs Geocentric models of the solar system Geocentric The earth was at the center of the solar system and all the planets, and the sun revolve around it Heliocentric The sun is at the center of the solar system and earth and other planets revolve around it. Planetary Motion Rotate- Spin on an axis Revolve- move around another object. Causes day and night On earth it causes seasons. Earth takes 24 hours to rotate on its axis It takes the earth 365.25 days to revolve around the sun. If the earth rotates, why don’t we feel it?!!! • As long as Earth spins steadily – and moves at a constant rate in orbit around the sun – you as an earthly passenger move right along with it. Revolution • Earth revolves around the sun in an elliptical orbit. • Because its orbit is an ellipse, earth’s distance from the sun varies • Perihelion – Earth is closest to sun • Aphelion – Earth is • farthest from sun Kepler's Laws Planets travel around the Sun in elliptical orbits ( not a true circle- oval shaped) with the Sun at one focus. A line from the planet to the Sun sweeps out equal areas in equal times. Therefore when the when the planet is closer to the sun it moves faster and when it is farther away it moves slower. The length of time that it takes a planet to orbit the earth and its distance to the sun are proportional. http://www.youtube.com/watch?v=5a2mcE-tzKE Newton’s Law Universal Gravitation 1.Every object in space attracts another with a force directly proportional to its mass. ( the more massive an object the greater its gravitational pull) 2.Gravitational force decreases with distance. 3.The force of gravity keeps the planets in orbit around the sun. • Earth’s axis is not straight – Earth’s axis is tilted 23.5° from vertical 23.5° tilt 24 Effects of the tilt of the Earth's axis 1. The earth rotates on an imaginary line that runs from the north pole to the south pole called an axis. 2. It is tilted at an angle of 23-1/2 degrees. 3. Because of this tilt along with the revolution of the earth around the sun some places experience different seasons. Effects of the tilt of the Earth's axis 4. Places along the lower latitudes (tropics) receive direct sunlight all the time and remains hot all year round. 5. When the earth is tilted towards the sun it receives direct intense sunlight and when it is tilted away from the sun it receives sunlight at an angle - less intense sunlight. Seasons 1. When the earth revolves around the sun it is tilted in the same direction at all time. 2 When the earth is tilted towards the sun, those places experience summer. 3. When the earth is tilted away from the sun, those places experience winter. 4. When it is neither tilted towards or away from the sun, those places are then experiencing spring or fall. http://www.youtube.com/watch?v=vDgUmTq4a2 Q&feature=related Why are days longer in the summer? • http://www.mathsisfun.com/earth-orbit.html Precession • A slow motion of Earth’s axis that traces out a cone over a period of 26000 years • Change in direction of axis without any change in tilt • http://www.youtube.com/watch?v=Dw4Xhw4q 4ec Precession • Change in the direction of the axis but without any change in tilt • Causes the North pole to point to different parts of the sky over a 26000 year period Nutation • Wobble around the precessional axis • Change in the tilt angle by ½ degree • Occurs over 18 year period • Due to moon exclusively • Slight effects on seasons Barycenter • The point between two objects where they balance each other. (the center of mass where two or more celestial bodies orbit each other) • As seen from above, a large planet orbits a star– or rather the star and planet orbit their shared center of mass, or barycenter. As seen from above, a large planet orbits a star–or rather the star and planet orbit their shared center of mass, or barycenter. • As seen from the side, a large planet and star orbit their shared center of mass, or barycenter, with the star seeming to shift back and forth. Two bodies with an extreme difference in mass orbiting a common barycenter internal to one body (similar to the Sun–Earth system) Two bodies with a major difference in mass orbiting a common barycenter internal to one body (similar to the Earth–Moon system) How many universes are there? • http://ed.ted.com/lessons/how-many-universesare-there Nat Geo Birth of the Universe • http://www.youtube.com/watch?v=PV0ACIykx QI