MSU SciFest 2021: Exo-lent Planets!

Presented at the virtual MSU Science Festival 2021 on April 10, 2021. Note that gifs and videos won't render in this pdf.

The Sun isn't the only star to have planets orbiting it -- thousands of alien worlds in other solar systems have been found, most of them in the last 10 years. There is a huge diversity in exoplanets types not seen in our own Solar System, like hot Jupiters and super Earths, and we've found a few exoplanets that would probably be habitable! In this talk you'll learn about how these exoplanets are formed, how scientists have discovered them, and why we shouldn't plan to visit one anytime soon.

More information on MSU SciFest: https://sciencefestival.msu.edu/
More information on exoplanets: https://exoplanets.nasa.gov/

Transcript

1. Exo-lent Planets!
   Dr. Abbie Stevens
   MSU & UMich
   Image credit: B. Watterson
   

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2. Dr. Abbie Stevens, MSU Science Festival 2021
   

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3. Tatooine, Star Wars
   Dr. Abbie Stevens, MSU Science Festival 2021
   

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4. (technically an
   exomoon…)
   Pandora, Avatar
   Dr. Abbie Stevens, MSU Science Festival 2021
   

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5. Krypton, Superman & DC Comics
   Dr. Abbie Stevens, MSU Science Festival 2021
   

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6. Omicron Persei 8, Futurama
   Dr. Abbie Stevens, MSU Science Festival 2021
   

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7. Vulcan, Star Trek
   Dr. Abbie Stevens, MSU Science Festival 2021
   

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8. The Stillness, The Broken Earth trilogy
   Dr. Abbie Stevens, MSU Science Festival 2021
   

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9. Arrakis, Dune
   Dr. Abbie Stevens, MSU Science Festival 2021 Image: M. Molnar
   

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10. Sargasso, Ratchet and Clank
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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11. Miller tidal planet, Interstellar
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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12. Asgard, Norse myth & Marvel comics
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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13. Gallifrey, Doctor Who
    Image: BBC
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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14. Caprica, Battlestar Galactica
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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15. What are exoplanets?
    Dr. Abbie Stevens, MSU Science Festival 2021
    planet - something in space that:
    Image: VectorStock
    

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16. What are exoplanets?
    Dr. Abbie Stevens, MSU Science Festival 2021
    planet - something in space that:
    (a) orbits around our Sun
    Image: VectorStock
    

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17. What are exoplanets?
    Dr. Abbie Stevens, MSU Science Festival 2021
    planet - something in space that:
    (a) orbits around our Sun
    (b) has enough mass for its own internal gravity
    to make it into a ball
    Image: VectorStock
    

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18. What are exoplanets?
    Dr. Abbie Stevens, MSU Science Festival 2021
    planet - something in space that:
    (a) orbits around our Sun
    (b) has enough mass for its own internal gravity
    to make it into a ball
    (c) is the biggest thing in its orbit
    Image: VectorStock
    

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19. What are exoplanets?
    Dr. Abbie Stevens, MSU Science Festival 2021
    planet - something in space that:
    (a) orbits around our Sun
    (b) has enough mass for its own internal gravity
    to make it into a ball
    (c) is the biggest thing in its orbit
    If only (a): comets, asteroids
    (a) & (b): moons, dwarf planets
    Image: VectorStock
    

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20. What are exoplanets?
    exoplanet – a planet outside our Solar System
    orbiting its own Sun (its ‘host’ star)
    planet - something in space that:
    (a) orbits around our Sun
    (b) has enough mass for its own internal gravity
    to make it into a ball
    (c) is the biggest thing in its orbit
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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21. Image: ESO/L. Calçada
    How are exoplanets formed?
    Protoplanetary disk
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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22. Image: ESO/L. Calçada
    How are exoplanets formed?
    Protoplanetary disk
    Dr. Abbie Stevens, MSU Science Festival 2021
    A real one around the
    baby star TW Hydrae
    Image: ALMA/S.Andrews/B.Saxon
    

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23. Dust
    Dr. Abbie Stevens, MSU Science Festival 2021
    How are exoplanets formed?
    

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24. Dust
    Rocks
    Dr. Abbie Stevens, MSU Science Festival 2021
    How are exoplanets formed?
    

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25. Dust
    Rocks
    Planetesimals
    (~1-5 miles)
    Dr. Abbie Stevens, MSU Science Festival 2021
    How are exoplanets formed?
    

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26. Dust
    Rocks
    Planetesimals
    (~1-5 miles)
    Dr. Abbie Stevens, MSU Science Festival 2021
    How are exoplanets formed?
    Protoplanets
    

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27. Dust
    Rocks
    Planetesimals
    (~1-5 miles)
    Planets!
    Terrestrials
    Gas giants
    Ice giants
    Dr. Abbie Stevens, MSU Science Festival 2021
    How are exoplanets formed?
    Protoplanets
    

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28. Dust
    Rocks
    Planetesimals
    (~1-5 miles)
    Planets!
    Terrestrials
    Gas giants
    Ice giants
    Total time: ~100 million years
    Dr. Abbie Stevens, MSU Science Festival 2021
    How are exoplanets formed?
    Protoplanets
    

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29. Dr. Abbie Stevens, MSU Science Festival 2021
    A brief history of exoplanets
    • 1st theorized by Giordano Bruno, late 1500’s
    

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30. A brief history of exoplanets
    • 1st theorized by Giordano Bruno, late 1500’s
    • 1st published discovery in 1988 (withdrawn in 1992,
    confirmed in 2003) (g cephei Ab by Campbell, Walker & Yang)
    • 1st confirmation of two rocky planets around a
    pulsar in 1992 (PSR B1257+12 b,c by Wolszczan & Frail)
    • 1st confirmation of an exoplanet orbiting a normal
    Sun-like star in 1995 (51 Pegasi b by Mayor & Queloz)
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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31. Two most successful methods to date:
    1. Radial velocity
    2. Transit
    Dr. Abbie Stevens, MSU Science Festival 2021
    How do we discover exoplanets?
    

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32. Radial velocity:
    GIF: Wikipedia
    Dr. Abbie Stevens, MSU Science Festival 2021
    How do we discover exoplanets?
    • Star wobbles due to gravity of
    the exoplanet
    • Color of light from the star
    shifts bluer and redder because
    of this motion, like listening for
    a siren to get higher then lower
    • Can help figure out mass of
    exoplanet
    

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33. Transit:
    Images: NASA Ames, D. Berry
    Dr. Abbie Stevens, MSU Science Festival 2021
    How do we discover exoplanets?
    • As the planet passes in
    front of the host star, it
    blocks a tiny amount of
    the star’s light
    • We can detect this change in
    brightness with sensitive
    telescopes
    • Can help constrain size of the
    exoplanet
    

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34. Transit:
    Images: NASA Ames, D. Berry
    Dr. Abbie Stevens, MSU Science Festival 2021
    How do we discover exoplanets?
    • As the planet passes in
    front of the host star, it
    blocks a tiny amount of
    the star’s light
    • We can detect this change in
    brightness with sensitive
    telescopes
    • Can help constrain size of the
    exoplanet
    

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35. CSA, 2003
    MOST
    NASA, 2009
    Kepler and K2
    CNES/ESA, 2006
    CoRoT
    NASA, 2018
    TESS
    Dr. Abbie Stevens, MSU Science Festival 2021
    How do we discover exoplanets?
    

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36. • 4 planet types: gas giant, super-Earth,
    Neptunian, and terrestrial
    • 3 temperature zones: hot, warm, cold
    Dr. Abbie Stevens, MSU Science Festival 2021
    Types of exoplanets
    

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37. TrES-2b
    • Hot Jupiter
    • About 700 LY away
    • Draco constellation
    • Reflects < 1% of
    incoming light -
    blacker than coal,
    air is the
    temperature of lava
    Image: D.A.Aguilar/TrES/Kepler/NASA
    Dr. Abbie Stevens, MSU Science Festival 2021
    Real exoplanets!
    

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38. Fomalhaut b
    § Cold gas giant?
    § 25 LY away
    § Surrounded by
    dust and debris
    § No near-infrared
    emission found
    Image: HST/NASA/P.Kalas
    Dr. Abbie Stevens, MSU Science Festival 2021
    Real exoplanets!
    

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39. Teegarden b and c
    • Warm terrestrials
    • 12 LY away
    • Aries constellation
    • Orbiting an evolved
    red dwarf star (lots
    of flares)
    Image: PHL at UPR Arecibo
    Dr. Abbie Stevens, MSU Science Festival 2021
    Real exoplanets!
    

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40. Tatooine types!
    (circumbinary planets)
    • Kepler 16b
    200 LY away, gassy,
    Cygnus constellation
    • Kepler 34b
    • Kepler 35b
    • Kepler 38b
    • Kepler 47b, c
    Image: ESO
    Dr. Abbie Stevens, MSU Science Festival 2021
    Real exoplanets!
    

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41. J1407b
    • 40x Jupiter mass
    • 434 LY away
    • Has ring system
    200x the diameter
    of Saturn’s rings
    (contain approx.
    an Earth’s mass
    of dust particles)
    Dr. Abbie Stevens, MSU Science Festival 2021
    Real exoplanets!
    Image: Ron Miller
    

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42. J1407b
    • 40x Jupiter mass
    • 434 LY away
    • Has ring system
    200x the diameter
    of Saturn’s rings
    (contain approx.
    an Earth’s mass
    of dust particles)
    Dr. Abbie Stevens, MSU Science Festival 2021
    Real exoplanets!
    Image: Ron Miller, Matt Kenworthy
    If it were at Saturn, we’d be able
    to see the rings!!!
    

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43. Kepler 7b
    • Hot Jupiter
    • As dense as
    Styrofoam
    • Same side of
    planet always
    faces the star
    • First exoplanet to
    have its clouds
    mapped!
    Dr. Abbie Stevens, MSU Science Festival 2021
    Real exoplanets!
    Image: NASA/JPL-Caltech/MIT
    

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44. Dr. Abbie Stevens, MSU Science Festival 2021
    Real exoplanets!
    

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45. Search on YouTube for ‘Kepler orrery’
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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46. 4,000+ confirmed exoplanets
    another 2,000+ candidates
    as of August 8, 2018
    52 are ‘habitable’
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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47. Image: PHL at UPR Arecibo
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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48. • Closest exoplanets: 4.2 light years
    Alpha Centauri B b
    Proxima b
    • Closest habitable exoplanet: 1,200 light years
    Kepler-62f
    Image credits: PHL @ UPR Arecibo
    Dr. Abbie Stevens, MSU Science Festival 2021
    Could we ever get to one?
    

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49. Bicycle: ~14mi/h
    Magical space bicycle from ISS:
    ~220,000,000 years to Alpha Centauri Bb
    ~62,000,000,000 years to Kepler-62f
    Apollo 10: ~40,000mi/h max*
    Fastest a human has ever gone*:
    ~71,000 years to Alpha Centauri Bb
    ~20,000,000 years to Kepler-62f
    * 2002 Guinness Book of World Records
    Dr. Abbie Stevens, MSU Science Festival 2021
    Could we ever get to one?
    

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50. So, realistically, we’d have to travel
    faster than the speed of light. Or at
    least reach relativistic velocities.
    Dr. Abbie Stevens, MSU Science Festival 2021
    Could we ever get to one?
    

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51. So, realistically, we’d have to travel
    faster than the speed of light. Or at
    least reach relativistic velocities.
    Or say goodbye to Earth then somehow
    safely cryogenically hibernate for a long
    time.
    Dr. Abbie Stevens, MSU Science Festival 2021
    Could we ever get to one?
    

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52. So, realistically, we’d have to travel
    faster than the speed of light. Or at
    least reach relativistic velocities.
    Or say goodbye to Earth then somehow
    safely cryogenically hibernate for a long
    time.
    Dr. Abbie Stevens, MSU Science Festival 2021
    Could we ever get to one?
    There’s no place like home. Warm, wet and with an atmosphere that’s just right, Earth is the only place we know of with life – and lots of it. JPL’s Earth science missions
    

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53. “It has been said that astronomy is a
    humbling and character-building experience.
    There is perhaps no better demonstration of
    the folly of human conceits than this distant
    image of our tiny world.
    To me, it underscores our responsibility to
    deal more kindly with one another, and to
    preserve and cherish the pale blue dot, the
    only home we've ever known.”
    - Carl Sagan, Pale Blue Dot: A
    Vision of the Human Future in Space
    Image by Voyage 1, 1990,
    6 billion km from Earth
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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54. Thank you!
    Resources:
    NASA: exoplanets.nasa.gov
    Planetary Habitability Laboratory:
    phl.upr.edu
    Exoplanet Orbit Database:
    exoplanets.org
    LCOGT Agent Exoplanet:
    agentexoplanet.lco.global/
    Zooniverse Planet Hunters TESS:
    zooniverse.org/projects/nora-dot-
    eisner/planet-hunters-tess
    Dr. Abbie Stevens, MSU Science Festival 2021
    

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55. Dr. Abbie Stevens, MSU Science Festival 2021
    Want to get involved?
    

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56. Dr. Abbie Stevens, MSU Science Festival 2021
    Want to get involved?
    

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57. Dr. Abbie Stevens, MSU Science Festival 2021
    

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