Kepler 452b: Earth 2.0 Discovered
TORONTO – Today NASA announced the discovery of Kepler-452b, an exoplanet that is very similar to our own orbiting a star some 1,400 light-years away in the constellation Cygnus (the Swan).
In a statement, Nasa said: “Today, and thousands of discoveries later, astronomers are on the cusp of finding something people have dreamed about for thousands of years – another Earth.”
The planet’s sun is 1.5 billion years older than our sun but has about the same mass and temperature. Kepler-452b is also about the same distance from its sun as the Earth is from ours, only about five million miles further away (1.05 AU).
This planet has been dubbed a “super-Earth” since it is about 60% larger than our planet. While it is not known if the planet has water, it is in what scientist call the habitable zone. That zone is the distance from its sun that allows water to pool on the planet’s surface in lakes, rivers and oceans. Kelper-452b has a slightly longer year than Earth, completing its annual rotation around its sun in 386 days.
“This is the first possibly rocky, habitable planet around a solar-type star,” Jeff Coughlin, Kepler research scientist at the Search for Extraterrestrial Intelligence (SETI) Institute in Mountain View, California, said during a news briefing
“We’ve gotten closer and closer to finding a true twin like the Earth,” Coughlin added. “We haven’t found it yet, but every step is important because it shows we’re getting closer and closer. And this current planet, 452b, is really the closest yet.”
The planet was discovered by using the Kepler Space Telescope which was launched into earth orbit in 2009. So far, the telescope has detected almost 4,700 exoplanets, but only a dozen or so that the mission managers believe are likely candidates for supporting life, at least as we currently define it.
“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 in a statement, referring to that just-right range of distances that could support the existence of liquid water on a world’s surface. “That’s substantial opportunity for life to arise, should all the necessary ingredients and conditions for life exist on this planet.
According to Space, Analyses of Kepler observations to date suggest that about 20 percent of the Milky Way’s stars harbor at least one rocky planet in the habitable zone, but this number will be revised or refined with additional study, researchers said.
“Continued investigation of the other candidates in this catalog and one final run of the Kepler science pipeline will help us find the smallest and coolest planets,” the SETI Institute’s Joseph Twicken, lead scientific programmer for the Kepler mission, said in a different statement. “Doing so will allow us to better gauge the prevalence of habitable worlds.”
The full text of the Kelper briefing by NASA can be found at http://www.nasa.gov/keplerbriefing0723.