Ten years after finding the first planet outside our solar system, scientists say they may be ready to move into a new phase of planetary exploration — one that examines distant worlds for signs of Earth-like life.

So far, astronomers have discovered some 145 so-called extrasolar planets orbiting stars besides our sun. All are gas giants like Jupiter, thought to be inhospitable to life as it is known on Earth.

But some of the world’s premier planet hunters indicated this could change in the next decade.

“Within a few years, we may be able to detect things like our own solar system,” said Mario Livio, an astrophysicist at the Space Telescope Science Institute. That could help answer what he termed the most intriguing question in science today: is there intelligent life anywhere besides Earth?

“The capability of seeing, detecting, planets the size of the Earth is only now just coming into our grasp,” said Jaymie Matthews, an astronomer at the University of British Columbia.

“I think we can look forward reasonably in the next decade to finding out are there Earth-size planets in Earth-like orbits going around every star,” said Tim Brown of the National Center for Atmospheric Research. “We’re going to have to wait a while to find out whether they have atmospheres.”

Matthews, Livio and Brown were among scientists gathered last week for a symposium on a decade of research into extrasolar planets at the Space Telescope Science Institute in Baltimore, which deals with data gathered by the Hubble Space Telescope.

Since the first extrasolar planet was detected in 1995 around a star known as 51 Pegasi, astronomers have uncovered dozens by identifying stars that wobble because of the gravitational pull of planets around them. They have found others by watching for a very slight dimming of stars caused by the orbiting of planets.

By Deborah Zabarenko

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