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
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 $550 million budget
4. Kepler at a glance 0.95-m aperture (Hubble is 2.4-m) 95 megapixel camera (at time, largest unclassified camera launched into space)
7. V = 13.3 mag Kepler First Light April 8, 2009
9. V = 13.3 mag Kepler data is saved every 30 min for ~150,000 stars
10. V = 13.3 mag Kepler makes a time-lapse movie of a star’s brightness
12. Once a year, viewed from afar, the Earth causes an 84 ppm (0.0084%) dip in Sunlight for about 10 hrs
14. Kepler-10 Light Curve
15. Kepler-10 Light Curve Period = 45.29 days
16. Kepler-10 Light Curve Period = 45.29 days
17. Kepler-10 Light Curve Period = .84 days Period = 45.29 days
18. Kepler-10 Light Curve Period = .84 days Period = 45.29 days
19. Transit Yields Planet Radius 10b Size Radius = 1.4 R !"#$%&'"()*&+,%-".. /,$."(0,12*.3 Dr. Natalie Batalha et al. 2011
20. Doppler Measurements Yield Planet Mass Mass = 4.6 M
21. Transit and Doppler Measurements Yield Density + 10b Size !"#$%&'"()*&+,%-".. /,$."(0,12*.3 Mass Volume = 8.8 g/cm3 Density
22. Composition of Kepler-10b
23. Kepler-10b was the first rocky planet discovered outside our own Solar System! (artist’s impression)
24. Dr. Susan Thompson et al. 2017
26. ~1 per star! Dr. Chris Burke et al. 2015
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)
28. What about planets suitable for life? A planet is “habitable” if its surface 0-100 C
29. 15%(±13%) of Sun-like stars host potentially habitable planets!
33. = Steve Howell The solar pressure on the Kepler spacecraft is ~50 µN m-2
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
36. (Mars)
37. Juliette Becker et al. 2015 K2 is still great at searching for new planets (though not Earth 2.0)!
38. Dr. Aaron Rizzuto et al. 2018 K2 shows young stars lack close-in planets!
39. Looking in the Ecliptic with K2, we are finding worlds that could potentially find us! Transit of Venus 2012 (Jim Tiller, AP)
41. Dr. Tim White et al. 2017
43. Star Earth Pulsations (starquakes) let us see into the interiors of stars!
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
46. Doug Caldwell In its 16th Campaign K2 is down to its last cup of hydrazine fuel!
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!