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Hunting Planets

  • Posted 08.28.14
  • NOVA

The hunt is on for Earthlike planets outside our solar system that may harbor life. Astronomer Geoff Marcy explains the challenges of finding infinitesimally small planets orbiting huge, very bright stars. By monitoring the light from distant stars, sensitive instruments can detect the very slight dimming that occurs when objects, such as orbiting planets, pass in front of them.

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Launch Video Running Time: 04:40

Transcript

NARRATOR: Geoff Marcy is one astronomer trying to directly answer that question. He's a planet hunter, scanning the heavens for signs of planets that may have already formed around other stars, thousands of light years away from our solar system.

GEOFF MARCY: It is actually quite a challenge to find planets around other stars. And the reason is very simple: planets don't shine, planets are essentially dark.

NARRATOR: By using advanced telescopes, dedicated planet hunters, like Geoff, have found ways to overcome this challenge.

GEOFF MARCY: If you watch a star, it ought to have the same brightness all the time—twenty-four/seven—but if there's a planet orbiting that star, when the planet crosses in front of the star, the planet will block a little of the starlight, and you'll see the star dim, a tiny amount, every time the planet crosses in front, over and over, in a repeated way. And, marvelously, you can learn the size of the planet, because the bigger the planet is, the more light from the star it blocks. And so we learn an enormous amount of information about these planets just by watching stars dim.

NARRATOR: Not surprisingly, most of the planets astronomers have found this way, are giant ones that block a lot of starlight.

By also observing the gravitational pull they have on their stars, Geoff calculates that most of these giant planets are made of gas and are unlikely to be habitable. But the Holy Grail is to find far smaller rocky worlds, like Earth, where the conditions for life could exist.

GEOFF MARCY: The challenge of finding Earth-sized planets is enormous; when an Earth crosses in front of a star, it blocks only one-one-hundredth of one percent of the light from the star.

NARRATOR: The Kepler space telescope is designed to detect this subtle dimming. Its mission: to focus on one tiny spot of space and scrutinize 150,000 stars for signs of planets the size of Earth.

Sensitive enough to detect minute dips in a star's light, Kepler is already producing mountains of data, and thousands of new planet candidates are being discovered.

GEOFF MARCY: Kepler has now already discovered a few planets that have a diameter and a mass that indicates clearly that the planet is rocky. And so we now have, for the first time in human history, definite planets, out there among the stars, that remind us of home.

NARRATOR: These first rocky planets are too close to their stars to sustain life, but the sheer number of smaller planets being found is transforming our view of solar systems beyond our own.

GEOFF MARCY: We've learned that nature makes some large planets, the size of Jupiter and Saturn; that nature makes even more of the smaller planets the size of Neptune, and even more of the planets the size of the earth. The number of planets is sort of like the rocks and pebbles you see on a beach. There are a few big boulders, there are many more rocks and there are an uncountable number of grains of sand that represent the Earth-sized planets we see in the cosmos.

NARRATOR: Geoff believes it's only a matter of time before we find a habitable planet.

GEOFF MARCY: I suspect that this scene we see here is one that reproduced, billions of times over, among the Earth-like planets, the habitable planets in our Milky Way galaxy.

Credits

FINDING LIFE BEYOND EARTH: ARE WE ALONE?

Written, Produced and Directed by
Oliver Twinch

Produced in cooperation with NASA and the National Institute of Aerospace

ASSISTANT PRODUCER
Alexis Burke
EDITED BY
Mairin O’Faolain
Dudley Sargeant
Nigel Barker
CAMERA
Jonathan Dacey
NARRATED BY
Jay O. Sanders
SOUND RECORDISTS
Percy Urgena
Gregg Hinnen
Haven McKinney
MUSIC
Universal Audio Network
VISUAL EFFECTS
Prime Focus
VISUAL EFFECTS SUPERVISOR FOR PRIME FOCUS
Simon Clarke
VISUAL EFFECTS LINE PRODUCER FOR PRIME FOCUS
Vikas Gandhi
VISUAL EFFECTS ASSISTANT PRODUCER FOR DARLOW SMITHSON PRODUCTIONS
Andrew Ryder
ONLINE EDITOR
Alan Jones
COLORIST
Blair Wallace
AUDIO MIX
Danny Finn
PROGRAM ADVISORS
Jim Bell David Grinspoon
ARCHIVE RESEARCH
Paul Gardner
James Labous
RESEARCH
Eloisa Noble
Faran Ismailpour
PRODUCTION COORDINATOR
Julia Speed
LINE PRODUCER
Ann Hampsey
ARCHIVAL MATERIAL
ASI
ASU
BBC Motion Gallery
Caltech
Carnegie Institution of Washington
Cassini Radar Team
Cornell University
ESA
ESO
Footage Vault
Gemini Observatory/AURA
Harvard University
HiRISE Imaging Team
Honeybee Robotics
Hubble
JAXA/Hayabusa Dome Movie Production Committee
JHU APL
Kennedy Space Center
NASA
NASA/Goddard Space Flight Center
NASA/JPL
Space Science Institute
Texas A&M University
The Institute for Solar Physics
University of Arizona
University of Rome
USGS
Washington University in St. Louis
SPECIAL THANKS
Southwest Research Institute
Caltech
Chris Abbas
David Chapman
Richard Kraus
Sarah Stewart
W. M. Keck Observatory
Harvard University
McGill University
Jacqueline Goordial
Lyle Whyte

FOR DARLOW SMITHSON PRODUCTIONS

DIRECTOR OF OPERATIONS
Ulla Streib
EXECUTIVE PRODUCER
Ben Bowie
NOVA SERIES GRAPHICS
yU + co.
NOVA THEME MUSIC
Walter Werzowa
John Luker
Musikvergnuegen, Inc.
ADDITIONAL NOVA THEME MUSIC
Ray Loring
Rob Morsberger
POST PRODUCTION ONLINE EDITOR
Spencer Gentry
CLOSED CAPTIONING
The Caption Center
MARKETING AND PUBLICITY
Karen Laverty
PUBLICITY
Eileen Campion
Victoria Louie
SENIOR RESEARCHER
Kate Becker
NOVA ADMINISTRATOR
Kristen Sommerhalter
PRODUCTION COORDINATOR
Linda Callahan
PARALEGAL
Sarah Erlandson
TALENT RELATIONS
Scott Kardel, Esq.
Janice Flood
LEGAL COUNSEL
Susan Rosen
DIGITAL PROJECTS MANAGER
Kristine Allington
DIRECTOR OF NEW MEDIA
Lauren Aguirre
ASSOCIATE PRODUCER
POST PRODUCTION Patrick Carey
POST PRODUCTION EDITOR
Rebecca Nieto
POST PRODUCTION MANAGER
Nathan Gunner
COMPLIANCE MANAGER
Linzy Emery
DEVELOPMENT PRODUCERS
Pamela Rosenstein David Condon
SUPERVISING PRODUCER
Stephen Sweigart
BUSINESS AND PRODUCTION MANAGER
Jonathan Loewald
SENIOR PRODUCER AND PROJECT DIRECTOR
Lisa Mirowitz
COORDINATING PRODUCER
Laurie Cahalane
SENIOR SCIENCE EDITOR
Evan Hadingham
SENIOR SERIES PRODUCER
Melanie Wallace
EXECUTIVE PRODUCER
Howard Swartz
MANAGING DIRECTOR
Alan Ritsko
SENIOR EXECUTIVE PRODUCER
Paula S. Apsell

A NOVA Production by Darlow Smithson Productions

© 2011 WGBH Educational Foundation All rights reserved

This material is based on work supported by National Aeronautics and Space Administration, Langley Research Center under the Research Cooperative Agreement No. NNL09AA00A awarded to the National Institute of Aerospace. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of National Aeronautics and Space Administration, Langley Research Center or the National Institute of Aerospace.

FINDING LIFE BEYOND EARTH: MOONS AND BEYOND

Written, Produced and Directed by
Oliver Twinch

Produced in cooperation with NASA and the National Institute of Aerospace

ASSISTANT PRODUCERS
Alexis Burke
Dominic Aston
EDITED BY
Mairin O’Faolain
Jason Savage
Nigel Barker
CAMERA
Jonathan Dacey
NARRATED BY
Jay O. Sanders
SOUND RECORDISTS
Percy Urgena
Gregg Hinnen
Haven McKinney
Pandora Kronenburg
MUSIC
Universal Audio Network
VISUAL EFFECTS
Prime Focus
VISUAL EFFECTS SUPERVISOR FOR PRIME FOCUS
Simon Clarke
VISUAL EFFECTS LINE PRODUCER FOR PRIME FOCUS
Vikas Gandhi
VISUAL EFFECTS ASSISTANT PRODUCER FOR DARLOW SMITHSON PRODUCTIONS
Andrew Ryder
ONLINE EDITOR
Alan Jones
COLORIST
Blair Wallace
AUDIO MIX
Danny Finn
PROGRAM ADVISORS
Jim Bell
David Grinspoon
ARCHIVE RESEARCH
Paul Gardner
James Labous
RESEARCH
Eloisa Noble
Faran Ismailpour
PRODUCTION COORDINATOR
Julia Speed
LINE PRODUCER
Ann Hampsey
ARCHIVAL MATERIAL
Artbeats
BBC Motion Gallery
Corbis
Getty
Joseph Resing/NOAA
Footage Vault
Woods Hole Oceanographic Institution
NASA
NASA/JPL
Caltech
NASA/Goddard Space Flight Center
Southwest Research Institute
Eastbay Astronomical Society
Cassini Radar Team
ESA
Hubble
ASI
ESO
Gemini Observatory/AURA
Max-Planck-Institute for Astronomy
Rice University
STScI
University of Arizona
DLR
ASU
JHU APL
GSFC
Space Science Institute
Universities Space Research Association
Lunar & Planetary Institute
University of Colorado
USGS
NCSA/MSU/UC San Diego
Swedish Solar Telescope / L. Rouppe van der Voort (University of Oslo)
The Institute for Solar Physics
Hawaii Institute of Geophysics and Planetology
SPECIAL THANKS
YMCA Snow Mountain Ranch
Space Telescope Science Institute
Chris Abbas
Emily Lakdawalla
Charles Fisher
Penn State University
Linda Amaral Zettler
Marine Biological Laboratory

FOR DARLOW SMITHSON PRODUCTIONS

DIRECTOR OF OPERATIONS
Ulla Streib
EXECUTIVE PRODUCER
Ben Bowie
NOVA SERIES GRAPHICS
yU + co.
NOVA THEME MUSIC
Walter Werzowa
John Luker
Musikvergnuegen, Inc.
ADDITIONAL NOVA THEME MUSIC
Ray Loring
Rob Morsberger
POST PRODUCTION ONLINE EDITOR
Spencer Gentry
CLOSED CAPTIONING
The Caption Center
MARKETING AND PUBLICITY
Karen Laverty
PUBLICITY
Eileen Campion
Victoria Louie
SENIOR RESEARCHER
Kate Becker
NOVA ADMINISTRATOR
Kristen Sommerhalter
PRODUCTION COORDINATOR
Linda Callahan
PARALEGAL
Sarah Erlandson
TALENT RELATIONS
Scott Kardel, Esq.
Janice Flood
LEGAL COUNSEL
Susan Rosen
DIGITAL PROJECTS MANAGER
Kristine Allington
DIRECTOR OF NEW MEDIA
Lauren Aguirre
ASSOCIATE PRODUCER POST PRODUCTION
Patrick Carey
POST PRODUCTION EDITOR
Rebecca Nieto
POST PRODUCTION MANAGER
Nathan Gunner
COMPLIANCE MANAGER
Linzy Emery
DEVELOPMENT PRODUCERS
Pamela Rosenstein
David Condon
SUPERVISING PRODUCER
Stephen Sweigart
BUSINESS AND PRODUCTION MANAGER
Jonathan Loewald
SENIOR PRODUCER AND PROJECT DIRECTOR
Lisa Mirowitz
COORDINATING PRODUCER
Laurie Cahalane
SENIOR SCIENCE EDITOR
Evan Hadingham
SENIOR SERIES PRODUCER
Melanie Wallace
EXECUTIVE PRODUCER
Howard Swartz
MANAGING DIRECTOR
Alan Ritsko
SENIOR EXECUTIVE PRODUCER
Paula S. Apsell

A NOVA Production by Darlow Smithson Productions

© 2011 WGBH Educational Foundation All rights reserved

This material is based on work supported by National Aeronautics and Space Administration, Langley Research Center under the Research Cooperative Agreement No. NNL09AA00A awarded to the National Institute of Aerospace. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of National Aeronautics and Space Administration, Langley Research Center or the National Institute of Aerospace.

IMAGE:

Image credit: Still from "Finding Life Beyond Earth" (planet and sun)
© WGBH Educational Foundation 2014

This is an excerpt from the NOVA program "Finding Life Beyond Earth."

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