Mountain View, CA. Today, astronomers have announced new evidence that small planets – the type of worlds most favorable for biology – may be more common than thought.  Once believed to accompany only stars with a large helping of heavy elements, this result suggests that – like weeds that can grow anywhere – Earth-size planets can be found around nearly any type of star.  The new work bolsters the chances that scientists will eventually succeed in discovering extraterrestrial biology.

A team of 29 Danish and American astronomers, led by Lars Buchhave, of the Niels Bohr Institute in Copenhagen, has analyzed data from both NASA’s Kepler space telescope and ground-based observatories to discover that even star systems that contain only sparse amounts of the heavy elements that make up planets can still get enough of this material together to form small worlds, the size of Earth or Mars.

This has two consequences in the search for extraterrestrial life: (1) The tally of small worlds is even greater than we once believed, and (2) Even relatively ancient stars, billions of years older than our Sun and generally deficient in such relatively heavy elements as silicon and iron, could host planets that are potential homes to life.  This circumstance may help in the discovery of intelligent life beyond Earth.

“The idea that very old stars could also sport habitable planets is encouraging for our searches,” notes Jill Tarter, the Bernard M. Oliver Chair for SETI at the SETI Institute.  “In particular, intelligent life has taken a long time to evolve here on Earth.  Consequently, it’s reasonable to suppose that older planetary systems are more likely to have technological societies – the kind we might detect with our radio telescopes.”

At SETIcon II, a public event being hosted by the SETI Institute, leading experts on planetary systems will be discussing where life might be discovered and how we could find it.  Among them will be planet-hunters extraordinaire Geoff Marcy, of the University of California, Deborah Fischer, of Yale University, and Jon Jenkins and Doug Caldwell of the SETI Institute.  SETIcon takes place June 22 – 24 at the Hyatt Santa Clara hotel in the heart of California’s Silicon Valley, and will feature approximately 50 panel discussions, fireside chats, and lightning talks.  Eminent guests from the worlds of science and science-fiction will be presenting at this unique event. For more information and registration, go to:

This latest discovery about so-called exoplanets adds to the growing evidence that planets are commonplace, but also that the smaller sorts of rocky worlds that could have both oceans and atmospheres are similarly ubiquitous.

“It could have been otherwise,” says Edna DeVore, Deputy CEO of the SETI Institute.  “For a half-century, our search for biology beyond Earth has been motivated by the assumption that planets – and more important, habitable planets – are abundant.  It might have turned out that this assumption was wrong.  But these new data from the Kepler Mission provide real support that what we hoped might be true really could be. Small planets which make good homes for ET are very likely everywhere. 

Accredited journalists wanting to attend SETIcon can sign up for complimentary press registration with Curtis Sparrer at

About SETI Institute


The SETI Institute ( is a private, non-profit, multi-disciplinary organization with a mission to explore, understand, and explain the origin, nature and prevalence of life in the universe. It comprises three centers: the Center for SETI Research, the Carl Sagan Center for the Study of Life in the Universe, and the Center for Education and Public Outreach. Our researchers have expertise in fields ranging from astrophysics and planetary science to biology and social science, as well as computer science and signal processing. Institute scientists study the past and present and thereby gain insight into the future, and we are committed to sharing this knowledge as scientific ambassadors to the public, the press, and the government.