Chris Lintott, astrophysics professor at the University of Oxford and research fellow at New College, taught students and public alike how to examine stars and find planet life Tuesday in the Great Hall of the Memorial Union.
Lintott’s lecture “How to Find a Planet Without Leaving Your Couch” featured how anyone can find planets with only a computer and some spare time.
Lintott used graphs and artists' renderings to guide listeners through the presentation, beginning with a picture of a spreading expanse of stars.
“Each of these places are not just a star system,” Lintott said. “These are places we can visit with worlds going around them.”
Lintott encouraged the audience to shift their thinking of the universe, looking at Earth as just another small light in a very large sky. Lintott said Earth is one planet among countless other planets orbiting stars of their own.
“The universe is bigger than we think it is,” said Jacob Norton, a freshman in engineering. “There’s more to life than just here on Earth.”
According to Lintott, NASA’s Kepler and TESS missions are helping hundreds of people shine light on this wider universe. Launched in 2011, the Kepler mission observed the brightness of 150,000 stars. Using the stars' light, scientists can detect countless planets, but it comes with a catch.
“Most of the planets we know about we can’t see directly,” Lintott said. “It’s not a question of the planets being too faint, strangely. It’s a question of the light of the stars overwhelming our view of the planets.”
Because of this problem, scientists have had to find indirect methods of detecting planets. Lintott explained stars are not static. In the case of our solar system, at the same time the sun pulls on the planets, the planets in turn pull on the sun. Lintott said his effect causes the sun — and other stars orbited by planets — to “wobble.”
Lintott said detecting and measuring this “wobble” in stars can help to find and measure the planets orbiting them. Such a method was used to discover the planet 51 Pegasus B, a gas giant orbiting a star at a proximity scientists previously thought impossible for a planet of such mass.
Sometimes, planetary discoveries come through an even easier method: looking at shadows.
If planets orbiting foreign stars have the right alignment, it is possible for telescopes such as Kepler to detect the dimming of a star’s light as a planet passes between the telescope and the star.
“This is something we can do on Earth occasionally as well,” Lintott said. “Twice every century or so, we see Venus going in front of the sun.”
Lintott said we know Venus is there because when it is in front of the sun, the sun is one tenth of one percent dimmer.
This is where citizen scientists and Planet Hunters enter the picture. According to Lintott, data from satellite telescopes like Kepler (and now TESS) are available to the public. Through programs like Zooniverse, where Lintott is a principal investigator, anyone can access celestial data and record the blips of shadows as planets pass in front of stars.
Planet Hunters is a group of volunteers willing to take up the challenge, and there are thousands of planets waiting to be discovered. The existence of many planets, Lintott said, would have previously been thought of as impossible.
Lintott said one discovered planet sits in space near four stars, creating something of a mystery as to how it could have formed without the opposing forces of gravity from the stars pulling it apart.
Tuesday’s audience listened to an animation of a planetary system set with a chime to go off whenever a planet completes an orbit around the central star. The orbits of all planets created a harmonious sound that Lintott explained was a perfect fifth, proving all planets of that system formed together to have such harmony.
“The fact that real people can actually discover things on their own […] I didn’t know about that website or that people were even allowed to do that and that type of professional data is open for public access,” said Elisa John, freshman in physics.
Elisa and a few other students said now that they know planet hunting is out there, it is something they would like to try.