Upload
thomas-madigan
View
66
Download
0
Embed Size (px)
DESCRIPTION
An overview of the Kepler mission, it's exciting new discoveries and the ever-growing variety of strange and wonderful worlds that populate our galaxy.
Citation preview
Professor Thomas Madigan
The Kepler Missionand
The Search for Exoplanets
Exoplanets: Extra solar planets or planets in orbit around other stars
Prime directive: to find Earth-like planets in the habitable zone of sun-like stars
Sunlike stars:G class, main sequence stars
Motivation: to complete the Copernican Revolution, to find our reflection in the cosmos
Mission Goals:Using the transit method and by taking large
samplings of data, investigate the range and configuration of planetary systems of target stars in the Lyra / Cygnus region of the sky
Determine the percentage of terrestrial and larger planets that are in or near the habitable zone of a wide variety of stars
Estimate how many planets exist in multiple-star systems and, with that, come to a conclusion regarding their sizes, shapes, mass and densities
Habitable Zone:directly linked to a star’s intrinsic luminosity, it is the region around the star where water can exist in a liquid state
For cooler, less luminous stars, it is closer to the star and less extensive
For hotter, more luminous stars, it is further out and more extensive
Solar System Temperatures and Environmental Parameters
Planet Distance (AU) Temperature (K) Notes
Mercury 0.387 633.65
Venus 0.723 463.59
Earth 1.000 394.19 Habitable zone (inner boundary)
1.116 373.14 Water transitions from gas to liquid
Mars 1.523 319.41
Ice Line 2.100 272.02 Habitable zone (outer boundary) - water transitions from liquid to solid
Asteroid Belt 2.800 235.57 Asteroid belt center of mass and semi-major axis of Ceres
Jupiter 5.204 172.80
Saturn 9.582 127.34
Uranus 19.229 89.89
26.200 77.01 Nitrogen transitions from gas to liquid
Neptune 30.103 71.85 Possible liquid nitrogen geysers on Triton
Pluto 39.481 62.74
Why Sun-like stars?
Life expectancy of G-class stars is measured in tens of billions of years
Habitable zone is far enough from the host star where life-inhibiting gravitational tidal-locking won’t occur
The Kepler InstrumentLaunched on March 6th, 2009, Kepler is a 1-meter
class, orbiting visible-light observatory
The Kepler Instrument
Using the transit method and modern, state-of-the-art Photometry, simultaneously monitors the light curves of over 100,000 target stars
Necessary sensitivity and precision: to accurately measure variations in intensity by one part in 10,000 for earth-like planets in the habitable zone of sun-like stars
The Kepler Instrument
The Kepler Instrument
Candidate stellar and planetary systems are confirmed using large, ground-based telescopes
Kitt Peak National Observatory
The 4-Meter Mayall Reflectorat Kitt Peak
The 4-Meter Mayall Reflectorat Kitt Peak
The Transit Method
We can’t visibly “see” the planet so how do we detect its presence?
– measure variations in the star’s intensity as the planet transits the star
– for earth-like planets in the habitable zone of sun-like stars, a sensitivity and accuracy of one part in 10,000 is necessary
The Transit Method
The Transit Method
The Transit Method
We can’t visibly “see” the planet so how do we determine the composition of the atmosphere?
Changes in the star’s spectra as the planet transits the star will reveal the composition of the planet’s atmosphere
Recent Findings
Kepler 22-b2-earth radii “Super Earth”
– 8 times the earh’s mass– 2x the gravity– believed to harbor abundant water
Recent Findings
Kepler 16 and 16-b“Tatooine”-like system