TABLE OF CONTENTS

1. TABLE OF CONTENTS Table of Contents: • Mission Overview • Scientific Objectives • Timeline • Spacecraft • Target Field of View • Transit Method • Johannes Kepler • Links Image from NASA Image from NASA Artist’s render of Kepler

2. MISSION OVERVIEW • Kepler is NASA’s first space telescope capable of finding Earth-size and smaller planets. • The mission is designed to survey our region of the Milky Way galaxy to detect and characterize hundreds of planets in or near the habitable zone using the transit method of planet detection. Image from NASA Concept art of Kepler Back to Table of Contents

3. Scientific Objectives 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: • Determine the percentage of terrestrial and larger planets there are in or near the habitable zone of a wide variety of stars; • Determine the distribution of sizes and shapes of the orbits of these planets; • Estimate how many planets there are in multiple-star systems; • Determine the variety of orbit sizes and planet reflectivities, sizes, masses and densities of short-period giant planets; • Identify additional members of each discovered planetary system using other techniques; and • Determine the properties of those stars that harbor planetary systems. Back to Table of Contents

4. TIMELINE • Kepler is scheduled to launch on March 6, 2009 from Cape Canaveral, Florida aboard a Delta II rocket. • After a commissioning period of appx. 45 days, Kepler will begin flight operations lasting at least 3.5 years, and will analyze data for at least 5 years. Image from NASA Target search region Back to Table of Contents

5. SPACECRAFT • The Kepler instrument is a specially designed 0.95-meter diameter telescope called a photometer or light meter. • It has a very large field of view — 105 square degrees, which is comparable to the area of your hand held at arm's length. • Using this wide field of view it will stare at the same star field for the entire mission and continuously and simultaneously monitor the brightnesses of more than 100,000 stars for the life of the mission. Image from NASA Kepler Photometer Back to Table of Contents

6. Target Field of View • Since transits only last a fraction of a day, all the stars must be monitored continuously, that is, their brightnesses must be measured at least once every few hours. The ability to continuously view the stars being monitored dictates that the field of view (FOV) must never be blocked at any time during the year. Therefore, to avoid the Sun the FOV must be out of the ecliptic plane. The secondary requirement is that the FOV have the largest possible number of stars. This leads to the selection of a region in the Cygnus and Lyra constellations of our Galaxy as shown. Image from NASA Kepler's targeted star field. Credit: Carter Roberts of the Eastbay Astronomical Society Back to Table of Contents

7. TRANSIT METHOD • Kepler uses the transit method to indirectly detect planets. • A “transit” occurs each time a planet crosses the line-of-sight between the star it orbits and the observer. • Transits block some of the light from the star, resulting in a periodic dimming. This dimming can be used to calculate the size and orbit of the planet. Image from NASA A planet in transit. Back to Table of Contents

8. JOHANNES KEPLER • The telescope is named after astronomer Johannes Kepler (1571 – 1630). • Kepler is known to be the founder of celestial mechanics and father of modern optics. Back to Table of Contents

9. LINKS • http://kepler.nasa.gov/ • http://planetquest.jpl.nasa.gov/Kepler/kepler_index.cfm • http://www.nasa.gov/mission_pages/hubble/science/exoplanet_transit.html Image from NASA Artist’s view of a transiting solar planet Back to Table of Contents