The Kepler Mission's Search for Earth 2.0

Outreach talk, 40 min. January 2018: Astronomy Days, North Carolina Museum of Natural Sciences, Raleigh, NC, USA.

Transcript

1. http://jjherm.es
   Dr. J.J. Hermes
   Hubble Fellow
   University of North Carolina
   at Chapel Hill
   The Kepler Mission’s
   Search for Earth 2.0
   

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3. PI: Bill Borucki
   1983: Kepler design began
   1992: REJECTED by NASA
   Unsuitable detector technology
   1994: REJECTED by NASA
   Too expensive
   1996: REJECTED by NASA
   No proof of concept
   1998: REJECTED by NASA
   Space too harsh for detectors
   2000: ACCEPTED by NASA
   $550 million budget
   

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4. Kepler at a glance
   0.95-m aperture
   (Hubble is 2.4-m)
   95 megapixel camera
   (at time, largest unclassified
   camera launched into space)
   

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7. V = 13.3 mag
   Kepler First Light
   April 8, 2009
   

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9. V = 13.3 mag
   Kepler data is saved every 30 min
   for ~150,000 stars
   

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10. V = 13.3 mag
    Kepler makes a
    time-lapse movie of
    a star’s brightness
    

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12. Once a year, viewed from afar, the
    Earth causes an 84 ppm (0.0084%)
    dip in Sunlight for about 10 hrs
    

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14. Kepler-10 Light Curve
    

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15. Kepler-10 Light Curve
    Period = 45.29 days
    

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16. Kepler-10 Light Curve
    Period = 45.29 days
    

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17. Kepler-10 Light Curve
    Period = .84 days
    Period = 45.29 days
    

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18. Kepler-10 Light Curve
    Period = .84 days
    Period = 45.29 days
    

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19. Transit Yields Planet Radius
    10b Size
    Radius = 1.4 R
    !"#$%&'"()*&+,%-"..
    /,$."(0,12*.3
    Dr. Natalie Batalha et al. 2011
    

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20. Doppler Measurements Yield
    Planet Mass
    Mass = 4.6 M
    

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21. Transit and Doppler
    Measurements Yield Density
    +
    10b Size
    !"#$%&'"()*&+,%-"..
    /,$."(0,12*.3
    Mass
    Volume
    = 8.8 g/cm3
    Density
    

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22. Composition of Kepler-10b
    

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23. Kepler-10b was
    the first
    rocky planet
    discovered
    outside our
    own Solar
    System!
    (artist’s impression)
    

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24. Dr. Susan Thompson et al. 2017
    

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26. ~1 per star!
    Dr. Chris Burke et al. 2015
    

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27. Kepler has shown us that, on
    average, each of the ~200 billion
    stars in our Galaxy has a planet
    orbiting within 300 days!
    (artist’s impression)
    

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28. What about planets
    suitable for life?
    A planet is
    “habitable”
    if its surface
    0-100 C
    

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29. 15%(±13%) of Sun-like stars host
    potentially habitable planets!
    

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33. =
    Steve Howell
    The solar pressure on the Kepler spacecraft is ~50 µN m-2
    

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34. Kepler, resurrected as K2, balances
    against the pressure of Sunlight
    But it must stare at new fields in the
    ecliptic plane every 3 months
    

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36. (Mars)
    

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37. Juliette Becker et al. 2015
    K2 is still great at searching for new
    planets (though not Earth 2.0)!
    

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38. Dr. Aaron Rizzuto et al. 2018
    K2 shows young stars
    lack close-in planets!
    

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39. Looking in the Ecliptic with K2,
    we are finding worlds that could
    potentially find us!
    Transit of Venus 2012 (Jim Tiller, AP)
    

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41. Dr. Tim White et al. 2017
    

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43. Star Earth
    Pulsations (starquakes) let us see
    into the interiors of stars!
    

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44. Kepler is in Earth-trailing orbit:
    Porb
    = 372.5 days
    Kepler is currently
    >96 million miles
    from Earth
    Earth’s orbit
    Kepler’s orbit
    Sun
    Earth on
    March 5th
    Kepler,
    1 yrafter launch
    Kepler,
    4 yrslater
    Orbital
    direction
    

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46. Doug Caldwell
    In its 16th
    Campaign
    K2 is
    down to
    its last
    cup of
    hydrazine
    fuel!
    

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47. How common is life
    in the Universe?
    Kepler: Of the 150 Sun-like stars
    within 50 lightyears, odds are that
    roughly 20 have an Earth-like planet!
    

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