LIVE INTERACTIVE YOUR DESKTOP May 24, 2012 NASA: How to Become a Planet Hunter: Careers in Space Science Presented by: Dr. Stephen Edberg

Exoplanet Discovery and Exploration: Expanding Geography Outside Our Solar System Stephen J. Edberg Exoplanet Exploration Directorate NASA Jet Propulsion Laboratory California Institute of Technology

There are 200 billion stars in our galaxy… …one of them is our Sun. The Sun has eight (or nine) planets… The Sun has eight (or nine) planets… …we know of one that has life. What about elsewhere?

There is a role for everyone who wants to be a part of this great exploration. Contributors include: astronomers astronomers planetary scientists planetary scientists physicists physicists mathematicians mathematicians computer scientists computer scientists engineers engineers artists artists educators educators public affairs officers public affairs officers business managers business managers and others and others

Stars are a billion times brighter…

…than the planet …hidden in the glare.

Like this firefly.

Planet Discovery Methods Direct Imaging (Vis & IR) Radial Velocity Transits Gravitational Microlensing Astrometry Pulsar Timing

Planets by Direct Imaging

NO Radial Velocity - 1

BLUE Radial Velocity - 2

Radial Velocity - 3 RED

Radial Velocity - 4 Single Line “Binary” - Planet

nm Star Spectrum Iodine Spectrum Planets by Radial Velocity: Actual Observation Method

Planets by Radial Velocity Single Line “Binary” - Planet Without Iodine Cell

Planets by Transit - 1

Planets by Transit - 2 Kepler Spacecraft

Transit Geometry z T( z, ) By observing the spectrum of the star + planet as the planet transits, we can determine the height of the atmosphere where it becomes opaque and determine its chemical composition. 19Traub Starlight passing through the planet’s atmosphere.

Transit/Occultation Weather Map

astronomers astronomers planetary scientists planetary scientists physicists physicists mathematicians mathematicians computer scientists computer scientists engineers engineers artists artists educators educators public affairs officers public affairs officers business managers business managers and others and others Gene Serabyn Gene Serabyn There is a role for everyone who wants to be a part of this great exploration. Contributors include:

astronomers astronomers planetary scientists planetary scientists physicists physicists mathematicians mathematicians computer scientists computer scientists engineers engineers artists artists educators educators public affairs officers public affairs officers business managers business managers and others and others Diana Blaney Diana Blaney There is a role for everyone who wants to be a part of this great exploration. Contributors include:

astronomers astronomers planetary scientists planetary scientists physicists physicists mathematicians mathematicians computer scientists computer scientists engineers engineers artists artists educators educators public affairs officers public affairs officers business managers business managers and others and others Ara Chutjian Ara Chutjian There is a role for everyone who wants to be a part of this great exploration. Contributors include:

astronomers astronomers planetary scientists planetary scientists physicists physicists mathematicians mathematicians computer scientists computer scientists engineers engineers artists artists educators educators public affairs officers public affairs officers business managers business managers and others and others Jan & Paul Chodas Jan & Paul Chodas There is a role for everyone who wants to be a part of this great exploration. Contributors include:

astronomers astronomers planetary scientists planetary scientists physicists physicists mathematicians mathematicians computer scientists computer scientists engineers engineers artists artists educators educators public affairs officers public affairs officers business managers business managers and others and others Jeanne M Holm There is a role for everyone who wants to be a part of this great exploration. Contributors include:

astronomers astronomers planetary scientists planetary scientists physicists physicists mathematicians mathematicians computer scientists computer scientists engineers engineers artists artists educators educators public affairs officers public affairs officers business managers business managers and others and others Sanjoy S Moorthy There is a role for everyone who wants to be a part of this great exploration. Contributors include:

astronomers astronomers planetary scientists planetary scientists physicists physicists mathematicians mathematicians computer scientists computer scientists engineers engineers artists artists educators educators public affairs officers public affairs officers business managers business managers and others and others Leslie L Lowes There is a role for everyone who wants to be a part of this great exploration. Contributors include:

astronomers astronomers planetary scientists planetary scientists physicists physicists mathematicians mathematicians computer scientists computer scientists engineers engineers artists artists educators educators public affairs officers public affairs officers business managers business managers and others and others Carolina Carnalla-Martinez There is a role for everyone who wants to be a part of this great exploration. Contributors include:

astronomers astronomers planetary scientists planetary scientists physicists physicists mathematicians mathematicians computer scientists computer scientists engineers engineers artists artists educators educators public affairs officers public affairs officers business managers business managers and others and others Joanne Kennedy Joanne Kennedy There is a role for everyone who wants to be a part of this great exploration. Contributors include:

What We Know About Planets About Planetary Systems What We Want to Know

Knowledge and Ignorance of Extrasolar Planets What we do know What we do know –Giant planet occurrence is high: ~7% –Mass distribution extends to near Earth’s mass –Eccentric orbits are common: scattering? –Many multiple systems of giant planets are known What we don’t know What we don’t know –Existence of terrestrial planets Are there low-mass planets in the ‘habitable zone’? Super-Earths certainly. Are there low-mass planets in the ‘habitable zone’? Super-Earths certainly. –Mass distribution of planets is incomplete and has strong selection effects What about spectral type? What about spectral type? Stellar age? Stellar age? Evolutionary state? Evolutionary state?

Planetary Systems: Questions Statistics of planetary systems Statistics of planetary systems –How common are planetary systems? –Are certain star types favored? –What is the distribution of planetary systems in the Galaxy? Characterizing planetary systems Characterizing planetary systems –What are the orbit radii? –Are the orbits circular or eccentric? –Are multiple-planet systems common? ? For multiple planet systems For multiple planet systems –What is the typical mass distribution of planets in a system? –What is the typical radius distribution? –Are the orbits co-planar? Must have astrometry to answer this Must have astrometry to answer this –Are the planets’ orbits stable?

How do we find out? About Planets About Planetary Systems What We Want to Know You can help us!

Small planet Massive planet Planets by Stellar Wobble

“The wobble effect”: our Solar System as seen at 10 pc distance 1 tick mark = 200 µas Sun-Jupiter wobble = 500 µas Sun-Earth wobble = 0.3 µas Principle of Astrometric Planet Detection How Much Wobble? It can be measured with an accuracy of about 1 μas (quite a bit thinner than the line plotted here).

Ordinary Telescope – Optical, IR, Radio An ordinary telescope collects electromagnetic radiation, forms an image which is then analyzed to determine the nature/position of the object in the field of view. Telescope diameter (D) detector Telescope Resolution Sensitivity  /D  D  = wavelength Airy Disk

Michelson Stellar Interferometry An interferometer combines the light from two or more small telescopes (Mersenne) to yield the angular resolution of a much larger telescope. Interferometer baseline (B) Telescope (d) Combiner & detector Interferometer Resolution Sensitivity /B  (2*d*B) = wavelength Fringe Pattern

SIM Lite could have made measurements precise enough to find Earths orbiting other stars.

But What Is a Habitable Planet? Not too big Not too big Not too small Not too small Not too hot or too cold Not too hot or too cold A good planet is: New spacecraft will be able to find planets similar in mass to Earth, at the “right distance” from their host stars. We can study them with advanced telescopes like...

Terrestrial Planet Finder – Interferometer (TPF-I) International TPF-I / Darwin: Emma X-Array

Terrestrial Planet Finder – Coronagraph (TPF-C) Images from 3 Types of Coronagraph Jupiter Earth

42 Terrestrial Planet Finder – Occulter (TPF-O) Big telescope (planet is faint!) Big occultor (few times size of telescope) Big separation (to see close to star) NWD Starshade JWST Target Star Planet

Blue (  m), Green (  m), Red (  m) Color Gives a First Impression of a Planet Solar system planets have colors that label them by type. Planet spectra

S. Seager Vegetation as a Surface Biosignature Visible photo Near-infrared photo

TPF Investigations The TPFs can distinguish between planets...

Searching for Other Earths You can search for other Earths if you Want to explore new worlds. Read and learn as much as you can in the subject that interests you. Learn to share your ideas clearly in writing.

Searching for Other Earths and, for my Aliens vs. Editor blog,

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