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http://planetquest.jpl.nasa.gov/overview/overview22.swf by Barbara Brown for ASTR 402 Spring, 2006 Kepler Mission test hypotheses: •Most stars like our Sun have terrestrial planets in or near the habitable zone •On an average two Earth-size planets form in the region between 0.5 and 1.5 AU What is a habitable planet? •Liquid water on planet surface--determined by size and temperature of the star and orbit of the planet •Size and mass of planet--small planets don’t have enough surface gravity to hold onto a life-sustaining atmosphere •Amount and composition of atmosphere •Affects of moons and giant planets in the system How are we going to do this? http://kepler.nasa.gov/media/KEPLER.SWF Kepler Mission Scientific Objective: The scientific objective of the Kepler Mission is to explore the structure and diversity of planetary systems. This is achieved by surveying a large sample of stars to: 1. Determine how many terrestrial and larger planets there are in or near the habitable zone of a wide variety of spectral types of stars; 2. Determine the range of sizes and shapes of the orbits of these planets; 3. Estimate the how many planets there are in multiple-star systems; 4. Determine the range of orbit size, brightness, size, mass and density of short-period giant planets; 5. Identify additional members of each discovered planetary system using other techniques; and 6. Determine the properties of those stars that harbor planetary systems. Expected Results: Based on the mission described above and assumption that planets are common around other stars like our Sun, then we expect to detect: From transits of terrestrial planets: •About 50 planets if most are the same size as Earth (R~1.0 Re), •About 185 planets if most have a size of R~1.3 Re, •About 640 planets if most have a size of R~2.2 Re, •About 12% with two or more planets per system. From modulation of the reflected light from giant inner planets: •About 870 planets with periods less than one week. From transits of giant planets: •About 135 inner-orbit planet detections, •Densities for 35 inner-orbit planets, and •About 30 outer-orbit planet detections. Characteristics of a planetary transit: •Period of recurrence of the transit •Duration of the transit •Fractional change in brightness of the star How can we detect a planetary transit? http://planetquest.jpl.nasa.gov/science/finding_planets.cfm What would a transit look like (on a graph)? http://planetquest.jpl.nasa.gov/transit/indexTransit.html The Kepler instrument: 0.95-meter diameter photometer telescope 105 degrees2 field of view Continuously and simultaneously monitor the brightnesses of more than 100,000 stars for the life of the mission—4 years http://planetquest.jpl.nasa.gov/Kepler/kepler_index.cfm Kepler Mission Team Members Scientific Operations Center at NASA Ames: William Borucki, Principal Investigator Mission Operations Center at University of Colorado LASP Data Management Center at Space Telescope Science Institute Industrial partner: Ball Aerospace, Boulder, CO Resources • http://kepler.nasa.gov • “Close-up on the Kepler Mission” by Jon Jenkins, www.space.com • “Solar transits: Tools of discovery” by Edna DeVore, www.space.com • http://planetquest.jpl.nasa.gov/Kepler/kepler_index.cfm • http://planetquest.jpl.nasa.gov/transit/indexTransit.html • http://www.ballaerospace.com/kepler.html • “Detecting other worlds: The photometric transit or 'Wink' method” by Dr. Laurance Doyle, www.seti.org • http://photojournal.jpl.nasa.gov/gallery/universe