Celestial Motion Chapter 21, pages 597-606 Chapter 22, pages 615-619 Lab starts this week NS 017 Peer Led Instruction Library Wednesday 6:30 to 8:30 PM Kristin Mooney Science Education Major Add ES104X CRN 11017 Can add before Oct. 3 session Do review questions to see if you think it help Sit in to see if it is for you Get your lab manual Do Prelab 1 and bring to lab class Lab starts with activities this week Make-ups are difficult to accomplish, so be sure to attend your lab regularly Must pass lab to pass class Tycho Brahe Detailed observations of movement of planets http://www.hao.ucar.edu/public/education/sp/images/tycho.html Tycho Brahe in his observatory His careful observations and records are his most important legacy Tycho s 1572 Nova observations http://www.hao.ucar.edu/public/education/sp/images/tycho.3.html http://www.hao.ucar.edu/public/education/sp/images/tycho.1.html
Tycho s comet of 1577 http://www.hao.ucar.edu/public/education/sp/images/tycho.2.html Tycho s model of solar system Discounted Copernicus model because he could not discern stellar parallax It does exist, he didn t have tools to see it http://www.hao.ucar.edu/public/education/sp/images/tycho.4.html Johannes Kepler Tycho s assistant and successor Used Tycho s data to determine planetary orbits are elliptical First Law of Planetary Motion Orbit of planet is ellipse Sun at one Focus http://en.wikipedia.org/wiki/image:johannes_kepler.jpg Kepler s 2 nd Law Kepler s third law of planetary motion p 2 =d 3 p=period (time to orbit Sun) in Earth years d=distance in Astronomical Units: 1 A.U.=distance from Earth to Sun Equal areas in equal time intervals accounts for the uneven speeds
Galileo Galilei Strong supporter of Copernican model of planetary movement Built 30x telescopes (from descriptions of the devices) and looked at planets and Moon starting in 1609 http://en.wikipedia.org/wiki/galileo_galilei#technology Galileo s notes on Jupiter s moons Telescope used to see that another body in solar system is a center of orbital movement These moons are not left behind, and Earth s Moon is not either Ptolemaic version of Venus Phases of Venus Galileo s explanation of Venus phases Moon s surface has texture
Galileo s Astronomical Discoveries When viewed by telescope, planets look like discs, not points of light as stars do Jupiter has moons Venus has phases Moon s surface has texture Sun rotates on an axis Foucault s Pendulum 1851 Proved Earth does rotate on its axis Copernicus hypothesis Isaac Newton Orbital motion of planets Invented the calculus to simplify calculations Explained the orbital motion of planets as the interaction of inertia and gravity Brief Review Sun is at the center of the solar system Published by Copernicus Supported by Galileo s telescopic observations of Jupiter and Venus Kepler determined orbits are ellipses Newton determined orbits created by interaction of inertia and gravity Constellations Star groups 88 recognized Stars names by brightness in them
Orion Southern Sky Hunter White Tiger Star names in Orion http://lithops.as.arizona.edu/~jill/epo/posters/orion/protoplanets.html http://borghetto.astrofili.org/costellazioni/costellazioni.htm Orion s place in the sky Bright star to lower left of Orion is Sirius Sirius The Dog Star Brightest star in sky In Canis Major http://www.windows.ucar.edu/the_universe/images/starmaps/map_orion.jpg http://www.windows.ucar.edu/cgi-bin/tour_def/the_universe/images/starmaps/map_canis_major_jpg_image.html Arcturus Second brightest in northern sky Very large Rather cool Celestial position http://en.wikipedia.org/wiki/arcturus http://www.windows.ucar.edu/cgi-bin/tour_def/the_universe/arcturus.html
Earth turns pointed at Polaris Polaris and Big Dipper Polaris and Big Dipper Polaris and Big Dipper Polaris and Big Dipper each 8 hours Mean Solar Day What is a day?
Sidereal Day What is a day? What is a day? Mean Solar Day 24 hours Sidereal Day 23 hours, 56 minutes Incredibly distant stars closest is 60,000+ times further than Sun Plane of the ecliptic Animation of equinox and solstice Equinox and solstice related to the plane of the ecliptic Constellations on the ecliptic
Axial wobble--precession Lab Starts this Week Room NS 017 Down the south stairs Do not miss class the first week Buy your lab manual and read the first lab Do the prelab questions, because your lab instructor may want you to hand them in http://video.google.com/videoplay?docid=4242610371139275474&q=precession+of+equinox&total=54&start=10&num=10&so=0&type=search&plindex=4 Animation link -- http://www.astro.virginia.edu/class/oconnell/astr121/im/lunation-anim.gif Moon s Motion Rotates on axis once each 27 1/3 days Same side always faces Earth No atmosphere extreme temperature variation: 127 o to -173 o C
Moon 3475 km diameter Density ~ Earth s mantle http://www.astrosurf.com/cidadao/moon_99_03_01.jpg Meteor Impact Compression Wave
Ejecta Rim Lunar Features Flood Basalt Euler Crater Maria Formation Lunar Exploration 10
Footprint in lunar regolith Moon formation http://www.psi.edu/hartmann/pic-cat/ Impact of asteroid Ejecta from impact http://www.psi.edu/hartmann/pic-cat/ http://www.psi.edu/hartmann/pic-cat/ Coalesced to form Moon Moon was initially hot http://www.psi.edu/hartmann/pic-cat/ http://www.psi.edu/hartmann/pic-cat/
Moon by Apollo 17 Crew Right part of photo is dark side that cannot be seen from Earth Rayed Crater http://spacekids.hq.nasa.gov/osskids/animate/moon.html http://cnr2.kent.edu/~manley/copernicus_crater_area.jpg Lab Starts this Week Room NS 017 Down the south stairs Do not miss class the first week Buy your lab manual and read the first lab Do the prelab questions, because your lab instructor may want you to hand them in