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CNET News Video
The search for Earth-like planets explainedHow close are we to finding alien life? CNET contributor Boonsri Dickinson visits Geoff Marcy's lab at the University of California at Berkeley to hunt for Earth-like planets. Using the Keck telescope in Hawaii and data from the Kepler telescope, Marcy...
-So, as you may notice, it's a little dark outside. It's supposed to be that way 'cause I'm here at the Berkeley campus and I'm gonna go looking for Earth-like planets. Now, I'm just waiting for him to get here. -Kudos, let's go inside. -Okay. -And here's the Remote Observing facility itself. This is Keck I and Keck II. These telescopes are located up high atop a hopefully dormant volcano called Mauna Kea at 14,000 feet. Well, some would say they are the world's best telescopes. You can see pictures of them here. Keck I and Keck II. These telescopes have a mirror that collects the light from the stars and galaxies, and the mirror is 10 meters in diameter. That's 1-tenth the size of a football field, and these mirrors are polished smooth to a parabolic shape to within 1 fraction of a wavelength of light. So, they're enormous mirrors practically the size of football fields. They're polished smooth to collect the light, bring it to a focus. And then what we do is we bring that light not to an eyepiece, but instead, we send the light into a spectrometer, which is a fancy word for prism. And the spectrometer spreads the white light of the star into all of its colors, blue, green, yellow, and red, and we can analyze those wavelengths of light, the colors of the rainbow to measure various properties of the stars. The most important thing is to try to detect planets. We're trying to find small Earth-size planets around nearby stars, stars that are within a few tens of light years of the Earth. And we're also studying stars that have been studied by the Kepler telescope, which is a space-borne telescope and its job is specifically to find Earth-size planets that dim their stars as the Earth cross in front blocking the starlight time and again and again. And so, we're studying the stars that the Kepler telescope has already indicated to us probably have planets. We're trying to verify if they have planets and measure the masses to see if they are truly Earth-size planets, but we found planets. In 1995, a wonderful astronomer in Geneva, Michel Mayor, found the first planet around the star, 51 Pegasi, and then our team found a lot of planets and ever since then, we found hundreds of planets. It's really been just an incredible change for Science, maybe you might even say a change in the way humans view ourselves and our place in the universe because we now know that our Earth and our solar system that goes around the Sun is not unique; there are other planetary systems out there; in fact, billions of them. And so, one of the things we are trying to do is find other Earth-like planets. This is Barnard's Star. This star is the second closest star to us here at the Earth. There's the Sun; there's Alpha Centauri and its system, and then Barnard's Star. So this is an extraordinary star. It's only-- I forgotten now exactly-- It's something like 5 or 6 light years away. You could almost throw a stone. You could pop over to Barnard's Star and borrow a cup of sugar assuming you didn't need the sugar for 700,000 years. The coordinates, the telescopes pointed there now. There's the star right there. The white dot is the star. And see a little black stripe right down the middle of the star? That's the entrance slit of the spectrometer into which the light is passing. And so the light goes into that slit and goes into the spectrometer where the white light gets spread out into all of its colors, blue, green, yellow and red and we analyze them. And that's what shows up over here. This is the actual spectrum and you can kind of see, while you can't really see the colors, but this is sort of a black and blue, white version of the rainbow of colors, and we're monitoring how much light comes from the star at each color, then we analyze that to measure the Doppler effect and the Doppler effect, if it changes with the star, that tells us that it has a planet. -When he was a graduate student, he asked this bold question. Can we find other planets that go around other Suns? He's actually found more than 70 of these extrasolar planets. -And a wonderful privilege and a lucky ride because we thought we wouldn't find any planets. And I thought for many years we would never find any planets and most other people thought we would never find any planets; so, I feel, you know, really lucky that we've been able to find lots of planets, big ones like Jupiter and small ones like nearly the size of the Earth. -I just got down searching for Earth-like planets, and it was super awesome. It puts our place in the universe into perspective.