NASA spots an Enormous Planet outside our Solar System, Orbiting Two Suns and Where Human Life is Possible

A team led by astronomers from NASA's Goddard Space Flight Center and San Diego State University have identified a new planet outside our solar system.

Using what's called the Kepler Space Telescope, they have seen this tiny tot orbiting two stars similar to the sun. But it's not really so tiny as it looks. The planet has got a mass and radius nearly identical to that of Jupiter, making it the largest transiting circumbinary planet ever found.

"It's a bit curious that this biggest planet took so long to confirm, since it is easier to find big planets than small ones," said SDSU astronomer Jerome Orosz, a coauthor on the study. "It took so long to confirm because its orbital period is so long."

Notably, the first one to spot Kepler was Laurance Doyle, a coauthor on the paper and astronomer at the SETI Institute, who noticed a transit back in 2011. However, more data and several years of analysis were needed to confirm the transit was indeed caused by a circumbinary planet. Interesting facts about this newbie:

Kepler-1647 is 3,700 light-years away and approximately 4.4 billion years old, roughly the same age as Earth.

The stars it is orbiting are similar to the sun, with one slightly larger than our home star and the other slightly smaller.

The planet takes 1,107 days (just over 3 years) to orbit its host stars. The planet is also much further away from its stars than any other circumbinary planet, breaking with the tendency for circumbinary planets to have close-in orbits.

Its orbit puts the planet within the so-called habitable zone.

Like Jupiter, however, Kepler-1647 b is a gas giant, making the planet unlikely to host life. Yet if the planet has large moons, they could potentially be suitable for life.

How the study is done

Planets that orbit two stars are known as circumbinary planets, or sometimes “Tatooine” planets, after Luke Skywalker’s home world in “Star Wars.” Using Kepler data, astronomers search for slight dips in brightness that hint a planet might be passing or transiting in front of a star, blocking a tiny amount of the star’s light.

“But finding circumbinary planets is much harder than finding planets around single stars,” said SDSU author William Welsh. “The transits are not regularly spaced in time and they can vary in duration and even depth.”

Once a candidate planet is found, researchers employ advanced computer programs to determine if it really is a planet. It can be a grueling process.

(Image credit: NASA)