Astronomers Find Eight Potentially Habitable Planets; Two may be Earth-like

Moscow (PNA/Sputnik) — Eight new planets have been discovered in so-called “Goldilocks” zones around alien stars. Such zones are believed to occupy a habitable area, where liquid water, and possibly life, can exist on a planet’s surface.

The discovery has been announced by the astronomers of the Harvard-Smithsonian Center for Astrophysics (CfA)in a statement on the official website of the center.

“Most of these planets have a good chance of being rocky, like Earth,” lead author Guillermo Torres said in the statement.

“We don’t know for sure whether any of the planets in our sample are truly habitable,” explains second author David Kipping of the CfA. “All we can say is that they’re promising candidates.”

Two of the newly discovered planets are believed to be very similar to Earth.

The two most Earth-like planets of the group are Kepler-438b and Kepler-442b. Both orbit red dwarf stars that are smaller and cooler than our Sun.

Kepler-438b circles its star every 35 days, while Kepler-442b completes one orbit every 112 days, the statement explains.

To be in the habitable zone, an exoplanet must receive about as much sunlight as Earth.

Too much sunlight would mean that any possible water would boil away as steam. Too little, and the water will freeze solid.

“For our calculations we chose to adopt the broadest possible limits that can plausibly lead to suitable conditions for life,” Guillermo Torres says.

The scientists say Kepler-438b receives about 40 percent more light than Earth. (In comparison, Venus gets twice as much solar radiation as Earth.) As a result, the team calculates it has a 70 percent likelihood of being in the habitable zone of its star.

Kepler-442b gets about two-thirds as much light as Earth. The scientists give it a 97 percent chance of being in the habitable zone.

The astronomers began their research by examining candidates for planets that had been identified by NASA’s Kepler mission (a mission searching for possible habitable planets). The candidates were analyzed using a supercomputer running algorithms at NASA’s Ames facility.

After exploring the statistical likelihood of the planets’ existence, the team spent one year gathering follow-up observations n the form of high-resolution spectroscopy, adaptive optics imaging, and speckle interferometry to thoroughly characterize the systems.

The results of the observations are set to be published soon in The Astrophysical Journal. (PNA/Sputnik) LAM/RSM