NASA Podcasts

Kepler: A Search for Habitable Planets
› View Video Now

Natalie Batalha, Professor of Astronomy & Physics, San Jose State University: We have an innate curiosity about our origins. Is life in our galaxy common? Does it exist? Are we alone? How unique is life here on Earth? The Kepler mission is one step in answering that question.

(Music – Show Title Slate: Kepler: A Search for Habitable Planets)

Patricia Boyd, Kepler Program Scientist, NASA HQ: The Kepler mission is a huge step forward in answering the question “What is our place in the universe?”

Jim Fanson, Kepler Project Manager, NASA JPL: The Kepler mission is NASA’s first mission capable of finding Earth-like planets orbiting other stars in the galaxy in a region around the star we call the habitable zone.

Bill Borucki, Kepler Principal Investigator, NASA Ames: The habitable zone is where we think water will be. If you can find liquid water on the surface, we think we may very well find life there. So that zone is not too close to the star, because it’s too hot and the water boils. Not too far away where the water’s condensed and ice-covered, a planet covered with glaciers. It’s the goldilocks zone, not too hot, not too cold, just right for life.

Natalie Batalha: The primary science goal of Kepler is to answer the question if earth-like planets in our galaxy are common or rare. Kepler’s going to detect planets via the transit method. What we aim to do is to measure the brightness’s of stars very, very accurately for a very long period of time without blinking. So that when the planet passes in front of a star, the light output from the star is going to dim just a little bit. That star is going to blink for about 12 hours and we will be able to measure that dip in brightness. And it’s that dip that we call a transit.

Riley Duren, Kepler Chief Engineer, NASA JPL: Kepler’s a different animal from the Hubble Space Telescope or the Spitzer Infrared Telescope because it doesn’t take pictures. You won’t see beautiful images that you see from Hubble because we’re not doing that kind of science. Those types of missions, like Hubble and Spitzer, are designed to focus on specific targets.

David Koch, Kepler Deputy Principal Investigator, NASA Ames: If you hold your hand at arm’s length with a grain of salt or a grain of sand, that’s about how much of the sky you can see with a normal astronomical telescope at any one time.

Jim Fanson: Kepler has a field of view that’s 10 degrees by 10 degrees.

David Koch: Our field of view is about as big as your hand at arm’s length covering the sky.

Riley Duren: So rather than taking pictures of very concentrated parts of the sky, we’re looking at taking a very broad snapshot of a lot of stars.

Nick Gaultier, Kepler Project Scientist, NASA JPL: Kepler takes really fuzzy pictures. But, the thing that Kepler is designed to do, and it does very well, is look for very small variations in the brightness of the stars.

Natalie Batalha: An earth-like planet passing in front of a sun-like star is going to cause the brightness of that star to dim by only 1 part per 10,000. That’s like looking at a headlight from a great distance and trying to sense the brightness change when a flea crawls across the surface. But the Kepler instrument is designed to detect such small changes in brightness.

Edna DeVore, Kepler Co-Investigator, SETI Institute: The Kepler sensors are CCDs. The CCD in your camera is about the size of one of your small fingernails. The CCD chips on the Kepler are a couple of inches square in pairs. And there’s 42 of those. In your camera, you might have a few megapixels. If you have a really nice camera, you might have 10 megapixels.

Bill Borucki: We have 96 million pixels and they have very low noise so we can find very small planets.

Edna DeVore: Once Kepler is launched from the Earth, it will go into what’s called an Earth-trailing orbit. Astronomers call that a heliocentric orbit, which means sun-centered orbit.

Bill Borucki: It looks at the stars continuously, day and night, 365 days a year and it slowly moves away from the Earth, orbiting the sun by itself.

Nick Gaultier: And from there, it will point itself at the Kepler field and stare at the Kepler field, nearly without blinking, for 3-and-1/2 years at least, maybe longer if we have an extended mission.

Patricia Boyd: Kepler will be looking in a region of the sky that you’ll see almost every night in the summertime.

Natalie Batalha: The field of view is kind of nestled underneath the wing of Cygnus the Swan between Cygnus and Lyra. Now in that area of sky, there are something like 6-and-1/2 million stars. Why do we need so many?

Nick Gaultier: Because of the way Kepler looks for planets, we have to have planetary systems that are lined up, so that the planet actually passes between the star and the Kepler telescope in its orbit.

Natalie Batalha: The probability of that happening, if you just throw stars randomly down in our galaxy, is something like 1 to 10 percent. It’s small. So of those 6-and-1/2 million, scattered over that 100 square degrees, only maybe 200,000 are interesting to us.

Nick Gaultier: We select the 170,000 or so that are most suitable to look at for planets with the Kepler telescope. Finally, we expect to end up with somewhere between a few hundred and a few thousand signals that are really planets around the stars that we’re looking at.

Jim Fanson: Well this is the first time that photometry, the measurement of the brightness of stars, will ever be done at this level of precision and it will be done simultaneously on more than 100,000 stars, continuously over a period of years.

Natalie Batalha: We’re somewhat like pioneers, very much like the explorers that were looking for new lands to settle and that’s how I see what we’re doing. We’re looking in this region of our galaxy for other habitable worlds.

Bill Borucki: I think people everywhere want to know, whether with all the stars out there, do they have planets that are earth-sized. Are Earths frequent or are they rare? And this gives us that answer. It’s the next step in mankind’s exploration of the galaxy.

Nick Gaultier: There’s two extreme answers that Kepler might give us. It might tell us that there’s an earth-like planet practically around every star we look at. Imagine the possibilities for life in the galaxy or life in the universe.

Patricia Boyd: If on the other hand we found out that Earth was very special and that the typical star like the sun is not hosting planets like the Earth, I think that would be a real surprise, as well. That would really make us reconsider the special nature of Earth.

Jim Fanson: We are now finally at the point where our technology allows us to build a machine that can make the observations to scientifically answer this question:

Patricia Boyd: How many stars like the sun did develop planets around them like the Earth? I think that’s such an important question to everyone and so interesting that we really have to do it and it’s a once-in-a-lifetime opportunity, right now.

Music full with closing graphics:
Kepler: A Search for Habitable Planets A NASA Discovery Mission
Science Operations: Ames Research Center
Program and Spacecraft Management: Jet Propulsion Laboratory

- - -

Photometer Design and Construction: Ball Aerospace & Technology Corp.
Post-Launch Mission Control: LASP - Univ. of Colorado at Boulder
Kepler Input Catalog: Smithsonian Astrophysical Observatory
Data Management: Space Telescope Science Institute
Education and Public Outreach: Lawrence Hall of Science - Univ. of California at Berkeley and SETI Institute.

- - -

Produced by the
NASA Ames Video Production Group
Moffett Field, Calif.
› View Video Now