Super Earth Found In Habitable Zone Within Lyra Constellation
April 18, 2013

Super Earth Found In Habitable Zone Within Lyra Constellation

Lee Rannals for — Your Universe Online

Astronomers have discovered what could be considered the most Earth-like planet ever found outside our Solar System.

The team used the Kepler Space Telescope to find Kepler 62f, a small rocky planet orbiting a Sun-like star in the Lyra constellation. The planet is about 1.4 times the size of Earth, and receives about half as much heat and radiation.

Kepler 62f is one of two "super-Earth" planets discovered in the star Kepler 62's habitable zone -- which means a planet is not so close that liquid water would boil off the face of the planet, and not so far away that it would be frozen. The planetary system's other super-Earth, Kepler 62e, is 1.61 times Earth's size and it gets about 20 percent more radiation and heat than Kepler 62f.

“The planets this small that we have found until now have been very close to their stars and much too hot to be possibly habitable," said Eric Agol, a University of Washington associate professor of astronomy who is the second author of the paper published in Science Express.

"This is the first one Kepler has found in the habitable zone that satisfies this small size,” Agol said in a statement. “Kepler 62f is the smallest size and the most promising distance from its star, which by these measures makes it the most similar exoplanet to Earth that has been found by Kepler.”

He said that while the sizes of Kepler 62e and 62f are known, their mass and densities are not.

“Based on its size, our best guess is that it´s rocky and has some atmosphere, but not a thick gaseous envelope, like Neptune,” Agol said.

Although both super-Earths around Kepler 62 are too small for their masses to be measured, astronomers believe they are composed of rock and water.

“Kepler-62e probably has a very cloudy sky and is warm and humid all the way to the polar regions. Kepler-62f would be cooler, but still potentially life-friendly,” said Harvard astronomer and co-author Dimitar Sasselov. “The good news is -- the two would exhibit distinctly different colors and make our search for signatures of life easier on such planets in the near future."

Lead author Lisa Kaltenegger, of the Max Planck Institute for Astronomy (MPIA) and the CfA, suggested there could be life on these planets.

"There may be life there, but could it be technology-based like ours? Life on these worlds would be under water with no easy access to metals, to electricity, or fire for metallurgy. Nonetheless, these worlds will still be beautiful blue planets circling an orange star -- and maybe life´s inventiveness to get to a technology stage will surprise us," Kaltenegger said.

Astronomers believe that the number of potentially habitable planets is far greater than previously thought. A team from Penn State´s Department of Geosciences said that if we were to look at 10 of the nearest small stars, we would probably find about four potentially habitable planets.