Kepler poised to solve an ancient riddle

One of the world's most prolific planet hunters, Geoff Marcy has made numerous groundbreaking discoveries, from the first transiting exoplanet to the first multiple-planet solar system discovered orbiting a star like our own.

He and his team, the California Planet Search, currently have 205 planet discoveries to their credit. He is a co-investigator for Kepler, NASA's first dedicated exoplanet mission, as well as for the planned SIM Lite Astrometric Observatory.

PlanetQuest spoke with Marcy about what's in store for the Kepler mission, which launched in March of last year. Kepler is currently watching 100,000 stars near the constellation Cygnus for signs of Earth-size planets.

PQ: Kepler has been in orbit for nearly a year and just recently released its first planet findings. How has the mission been going so far?

Marcy: Kepler is working beautifully. It can measure the brightnesses of stars to a precision that's unprecedented, better than one part in ten thousand ? there's nothing even close to its ability to constantly monitor thousands of stars.

PQ: Shortly after launch, it was announced that there were some problems with the CCD amplifiers on Kepler. How has that affected the mission?

Marcy: It's a very minor inconvenience. A small fraction of the mission's 42 CCD's are affected, and not badly. Kepler is still just as precise as planned and is producing results with mind-blowing quality.

PQ: Some high-profile scientists have predicted that Kepler will find an Earth-like planet within a year. Do you think this is likely?

Marcy: It's presumptuous to predict that Kepler will find Earth-like planets. We may find that Earths are a dime a dozen or we might find that they are a rare treasure. We might even find zero Earth-like planets, which would be a spectacular result and suggest that our planet is an extraordinary contradiction to the norm.

If we do find Earth-like planets, it will take more than a year to identify them. Kepler needs to observe a planet passing in front of its star three times in order to confirm its existence. For a planet with the same orbit as the Earth, that's over three years to wait.

PQ: What impact do you think Kepler's findings will have on society once the mission is finished?

Marcy: It will deeply enrich our understanding of our own Earth - whether it is one of many similar planets or a precious cosmic oasis. If habitable planets are common, we will have to think very hard about the next step - searching for intelligent life. Kepler could be a stepping-stone to connecting us with other habitable planets or even our brethren in the universe.

PQ: Given the impact of finding a habitable planet, do you hope that Kepler's planet hunt will prove that Earths are common?

Marcy: I think it's important to remain unbiased. As scientists, we need to make sure to keep an open mind so that we can faithfully report our findings and avoid over-interpreting our data. We can make mistakes if we want a certain answer badly. Quality data are most important, so I try to stay calm, vigilant, and self-critical.

PQ: Anything else people should know about Kepler?

Marcy: Stay tuned! We're close to answering questions that the ancient Greeks pondered, questions humans have asked ever since our ancestors first ambled down from the trees.

 

Source: PlanetQuest / Jet Propulsion Laboratory
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