Expert Voices

The Hunt for Exoplanets Heats Up

Artist's impression of Kepler 186f
This artist's impression depicts Kepler 186f, a planet located 500 light years from Earth that is thought to be in the habitable zone, where it gets enough sunlight to harbor liquid water and potentially maybe even life. (Image credit: NASA)

Marie-Eve Naud is the University of Montreal Ph.D. student who led analysis that recently uncovered a previously unknown giant planet using infrared light. The planet, known as GU Pisces b, is one of the most unusual exoplanets found to-date, with a mass 10 times greater than Jupiter's and orbiting its star at 2,000 times the distance between Earth and our sun. (Image credit: Marie-Eve Naud)

Kelen Tuttle, writer and editor for the Kavli Foundation, contributed this article to's Expert Voices: Op-Ed & Insights.

It's a time of amazing discovery in the hunt for planets in other solar systems. Over the past six months, more than 700 exoplanets have been found. It seems that each week brings the announcement of another foreign world: a rocky orb that seems much like Earth except that it's 17 times more massive; a colossal planet that orbits its star at a whopping 2,000 times the distance between Earth and our sun; an Earth-like planet in a two-sun system.

On July 9, three astrophysicists — Zachory Berta-Thompson, Bruce Macintosh and Marie-Eve Naud — came together to discuss this explosion in exoplanet  discovery in a live webcast hosted by The Kavli Foundation, part of a continuing series that gives viewers a chance to ask questions of scientists at the forefront of some of the world's most exciting research.  (To keep up to date on future webcasts, follow the foundation on Twitter: @KavliFoundation)

In June 2014, astronomers discovered the first planet orbiting one star in a two-start system, as shown in this artist's impression. (Image credit: Cheongho Han, Chungbuk National University, Korea)

"What is really fascinating at this stage of exoplanet science is that we have many methods, and all the methods can help to find given planets — planets with certain characteristics — and bring different information," said Naud, a University of Montreal Ph.D. student who led a recent study that discovered a strange gas giant exoplanet called GU Pisces b. "When we are able to combine different methods, we are able to see so much more."

Bruce Macintosh is the principal investigator for the Gemini Planet Imager, which searches for planets from the Gemini South telescope. GPI recently snapped its first image, thereby producing the best-ever direct photo of a planet outside our solar system. Macintosh is also a Professor of Physics at Stanford University and a member of the Kavli Institute for Particle Astrophysics and Cosmology. (Image credit: Bruce Macintosh)

Combining planet-hunting methods has not only enabled the recent explosion in exoplanet discovery , but has also increased what can be inferred about each planet. Scientists are now able to determine an exoplanet's characteristics including its size, mass and density, as well as the chemical make-up of the planet and its atmosphere.

Zachory Berta-Thompson is the Torres Fellow for Exoplanetary Research at the MIT Kavli Institute for Astrophysics and Space Research. He hunts for exoplanets as a member of the MEarth Project, a survey to find small planets orbiting the closest, smallest stars. (Image credit: Zachory Berta-Thompson)

What's especially exciting about identifying these chemicals is that they "can tell you things like the history of the planet — how it formed," said Macintosh, a member of the Kavli Institute for Particle Astrophysics and Cosmology and the principal investigator for the Gemini Planet Imager. "We think we understand enough about the process that formed planets in our solar system to see that it left a chemical signature in the atmosphere of, say, Jupiter and we can try to look for that same chemical signature in the atmosphere of other planets."

All three scientists agreed that, in addition to finding and characterizing planets, there's another burning question that makes them excited to come to work each day: the hunt for planets that could support life.

"I think it'll be really tough, but … thanks to the Kepler mission , we now know that the rate of occurrence of potentially habitable planets around small stars is ... more than one out of ten," said Berta-Thompson, the Torres Fellow for Exoplanetary Research at the MIT Kavli Institute for Astrophysics and Space Research. "And so this does really increase our chances."

For more on the three astrophysicists' expectations for finding life on other planets, their favorite of the 1700 planets discovered so far, and the burning questions that makes it exciting from them to come to work each morning, watch the complete discussion, recorded live during a Google Hangout.

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