It’s Time for Next Phase in Search for Alien Life, Scientists Say

[dropcap]With[/dropcap] more and more Earth-like alien planets being discovered around the galaxy, humanity should now start planning out the next steps in its hunt for far-flung alien life, researchers say.

On Thursday (April 18), scientists announced the discovery of three more potentially habitable exoplanets — Kepler-62e, Kepler-62f and Kepler-69c — further suggesting that the cosmos is jam-packed with worlds capable of supporting life as we know it.

So the time is right to get the ball rolling beyond mere discovery to the detailed study and characterization of promising alien planets, researchers said — a task that will require new and more powerful instruments.

“You really want to collect the light from these planets, to figure out — take the data, not just infer —whether or not there’s water, and even signs of life, on these planets,” Lisa Kaltenegger of the Max Planck Institute for Astronomy and the Harvard-Smithsonian Center for Astrophysics, who was part of the team that discovered Kepler-62e and f, said during a press conference Thursday.

 Billions of Earth-like planets

As their names suggest, the three newfound planets were discovered by NASA‘s prolific Kepler space telescope, which has spotted more than 2,700 potential alien worlds since its March 2009 launch. Just 122 have been confirmed to date, but mission scientists expect more than 90 percent will end up being the real deal.

The $600 million Kepler mission was designed to determine how common Earth-like planets are around the Milky Way galaxy. Its observations so far suggest our home planet may not be so special.

For example, astronomers recently used Kepler data to estimate that 6 percent of the galaxy’s 75 billion or so red dwarfs — stars smaller and dimmer than the sun — likely host habitable, roughly Earth-size planets.

That works out to a minimum of 4.5 billion “alien Earths,” the closest of which may be just 13 light-years or so away, according to the study.

While Kepler’s work is not done, the instrument has already laid the foundation for the next generation of exoplanet missions, mission team members said.

“In many ways, Kepler was a scout. It scouted deep into the galaxy to find out what the frequencies were, and to show there were a lot of planets to find. It’s accomplished that,” Kepler science principal investigator Bill Borucki of NASA‘s Ames Research Center in Moffett Field, Calif., who led the team that found Kepler-62e and f, said at Thursday’s press conference.

“And now these new missions will come online and give us more information about these planets,” Borucki added, referring to efforts such as NASA‘s Transiting Exoplanet Survey Satellite, which will launch in 2017 to search for nearby alien worlds. “But the big step is that step where we first start measuring the composition of the atmospheres, and that will be a very technologically difficult task.”

Mike Wall - SPACE.com