http://planetquest.jpl.nasa.gov/overview/overview22.swf

                   

                                                                                                                                                    by Barbara Brown

for ASTR 402Spring, 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

http://kepler.nasa.gov/media/KEPLER.SWF

How are we going to do this?

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

http://planetquest.jpl.nasa.gov/science/finding_planets.cfm

How can we detect a planetary transit?

http://planetquest.jpl.nasa.gov/transit/indexTransit.html

What would a transit look like

(on a graph)?

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

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

Kepler Mission Team Members

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