By Barry Eitel
SAN FRANCISCO
A team of researchers announced Thursday they have discovered an Earth-like planet orbiting a star at the perfect distance for liquid water to appear on its surface.
NASA is calling the planet, known as Kepler 452b, “Earth 2.0.” In 20 years of searching, the conditions on Kepler 452b are closer to those found on Earth than any other known planet.
Astronomers have long known that the other planets in the solar system are not hospitable to life as we know it. Many have theorized, however, that far-out exoplanets, meaning planets circling stars that are not our sun, could have conditions parallel to the only planet we know of that harbors life – Earth.
“We can think of Kepler-452b as an older, bigger cousin to Earth, providing an opportunity to understand and reflect upon Earth’s evolving environment," Jon Jenkins, the analyst who led the team that discovered Kepler-452b, said in a statement.
The similarities between Kepler 452b and Earth are striking. The star the exoplanet revolves around, Kepler 452, is the same class of star as our sun, and it has roughly the same temperature and mass. It is about 60 percent larger than Earth and has a year of 385 days. Kepler 452b is in the “habitable zone,” meaning it is orbiting at a distance around its star that would, theoretically, support liquid water at its surface.
The exoplanet and its star are 1.5 billion years older than the sun.
"It’s awe-inspiring to consider that this planet has spent 6 billion years in the habitable zone of its star; longer than Earth,” Jenkins said. “That’s substantial opportunity for life to arise, should all the necessary ingredients and conditions for life exist on this planet.”
Contact with any possible alien civilization on the planet is probably not coming anytime soon. Kepler-452b is 1,400 light-years away from Earth. It would take New Horizons, the fastest spacecraft yet created by humanity, almost 26 million years to reach it.
