Kepler 62’s newfound worlds are not quite small enough to be considered strict replicas of Earth, but the results have strengthened the already strong conviction among astronomers that the galaxy is littered with billions of Earth-size planets, perhaps as many as one per star, and that astronomers will soon find Earth 2.0, as they call it — our lost twin bathing in the rays of an alien sun.

“Kepler and other experiments are finding planets that remind us more and more of home,” said Geoffrey Marcy, a longtime exoplanet hunter at the University of California, Berkeley, and Kepler team member. “It’s an amazing moment in science. We haven’t found Earth 2.0 yet, but we can taste it, smell it, right there on our technological fingertips.”

A team of 60 authors, led by Mr. Borucki, reported the discovery of the Kepler 62 planets on Thursday in an article published online in the journal Science and at a news conference at Ames.

As if that weren’t enough, a group led by Thomas Barclay of Ames and the Bay Area Environmental Research Institute also reported the discovery of a planet 1.7 times as big as Earth hovering on the inner, warmer edge of the Goldilocks zone of Kepler 69, a star almost identical to the Sun, 2,700 light-years distant. At the news conference, Dr. Barclay described the planet as perhaps a “Super-Venus.” The group’s paper was published on Thursday in The Astrophysical Journal.

And in another paper submitted to The Astrophysical Journal, a group led by Lisa Kaltenegger of the Harvard-Smithsonian Center for Astrophysics and the Max Planck Institute for Astronomy, in Heidelberg, Germany, took the first stab at trying to model conditions on the Kepler 62 planets. That is a tough job because the system is too far away for astronomers to measure the masses of these planets, which would allow the densities and compositions of the planets to be pinned down, or to inspect and analyze their atmospheres with telescopes.

Scaling up from the properties of the Earth, Dr. Kaltenegger and her colleagues concluded that both of them were probably ocean worlds with humid, cloudy skies. Any life on them would probably be aquatic, she said, but “it might even be cooler life than we have here. Looking at the oceans, we find a lot of interesting life-forms there.”

Dr. Kaltenegger said she envisioned the pair as a kind of Darwinian test tube and wondered in an e-mail if life would evolve on both worlds and, if so, “Would life evolve ‘the same’ way or would there be very different life?”