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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