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Wendy Stenzel/NASA Kepler Mission

Kepler in space

NASA hits set back in search for extraterrestrial life

by Julie Davis
May 16, 2013


JPL-Caltech/NASA Ames Research Center

The Kepler mission has found four potentially habitable planets. Here they are  lined up with the Earth on right.

While technical difficulties on NASA’s Kepler space telescope may bring to a close one chapter in the search for extraterrestrial life, the quest is far from over. The Adler Planetarium has invited citizen scientists to use Kepler’s data by taking part in the Zooniverse Planet Hunters program.

The Zooniverse program allows ordinary people to take a look at the telescope data and aid scientists in the search for Earth-like planets.

“There’s about 800,000 people who are now members of Zooniverse … who’ve helped analyze and classify real data. I’m one of them.” said Geza Gyuk, director of astronomy at the Adler Planetarium.

After more technical difficulties, NASA’s hugely successful Kepler space telescope, orbiting the sun, may end its mission. Earlier this week the Kepler team discovered that the space telescope had gone into “safe mode,” as a response to technical difficulties.

Throughout the spring the telescope has had problems with one of its reaction wheels, which are the part of the telescope that keep in facing the right direction.

“With the failure of a second reaction wheel, it's unlikely that the spacecraft will be able to return to the high pointing accuracy that enables its high-precision photometry,” NASA scientists said in a statement Wednesday. “However, no decision has been made to end data collection.”

High-precision photometry is technology which, like a digital camera, creates images using light sensitive cells. Unlike a camera, the images it collects are deliberately out-of-focus to better enable scientists to analyze the light.

Scientists look for occasional brief dimming of starlight which occurs when a planet passes between the telescope and the star. Kepler orbits the sun to collect continuous data from one patch of space that scientists estimate contains 100,000 sun-like stars.

The Kepler mission has made big advances in the search for Earth-like planets and extraterrestrial life.

Gyuk said some of Kepler’s significance comes from its ability to help scientists fill in another variable on what is known as the Drake equation. Astrophysicist Frank Drake presented the equation in 1961. It identifies eight variables that could help scientists determine the number of civilizations that may exist in our galaxy.

“For a very long time we didn’t know any of these numbers except for the number of stars in the galaxy,” Gyuk said. “The Kepler has really been fantastic about nailing down stars and planets and where are they located. We’re slowly beginning to convert the Drake equation into a tool for organizing our thoughts, where we could plausibly begin calculating things. That’s really fantastic.”

To date, Kepler’s planet count includes 132 confirmed planets, 2,740 planet candidates and 2,165 eclipsing binary stars, or star systems where two stars orbit around a center mass.

The Kepler mission has identified four planets within the “habitable zone” of a star, meaning it should be possible for liquid water to exist on the planet.

Fred Rasio, professor of physics and astronomy at Northwestern University, said Kepler “has opened a completely new territory. It has increased the statistics on exoplanetary systems.” He said the Kepler data has confirmed two things: first many other planetary systems exist around stars in our universe; and second, our universe is unique among the systems we’ve observed so far.

The Kepler spacecraft launched successfully in March 2009, but trouble began in July 2012 when a first reaction wheel broke after nearly seven months of difficulties. In January 2013 a second reaction wheel malfunctioned. The team rehabilitated it, but it malfunctioned again in early May.

The telescope is safe for the time being in a resting mode designed to conserve fuel. NASA engineers will continue efforts to fix the spacecraft for several months to come. 


“I think everyone is really hoping the engineers can pull off another miraculous save,” said Gyuk

According to NASA, “Even if data collection were to end, the mission has substantial quantities of data on the ground yet to be fully analyzed, and the string of scientific discoveries is expected to continue for years to come.”

Gyuk said the Kepler mission’s importance extends far beyond scientific research. It touches on questions that have long trouble humanity, buried deeply in our collective imagination. “Every time we’ve expanded our boundaries we’ve wondered if there are people,” he said.