The exoplanet is located very close to our solar system

Jan 7, 2014 07:43 GMT  ·  By

Using data collected by the NASA Kepler space telescope, a team of international astronomers was recently able to discover the first-ever, Earth-mass extrasolar planet. Experts have been looking for Earth-analog exoplanets for many years, so this discovery marks a historic moment in astronomy.

Of more than 3,500 exoplanetary candidates Kepler has identified to date, the newly-discovered world is the lightest to have its mass and physical size determined with accuracy. Scientists were able to confirm that the world, called KOI-314c, is roughly 60 percent larger than Earth.

Despite its larger size, the two worlds weigh the same, since KOI-314c has a very low density. Experts with the Harvard-Smithsonian Center for Astrophysics (CfA), who led the investigation, say that the alien world is most likely surrounded by a very thick, gaseous atmosphere.

Details of this interesting exoplanet were presented during a press conference held on Monday, January 6, at the 223rd meeting of the American Astronomical Society, held in Washington, DC. The study was led by CfA investigator David Kipping. He told attendants that KOI-314c is not like Earth at all.

“This planet might have the same mass as Earth, but it is certainly not Earth-like. It proves that there is no clear dividing line between rocky worlds like Earth and fluffier planets like water worlds or gas giants,” he said during the presentation.

According to the Kepler data used for this study, KOI-314c orbits the dim red dwarf star KOI-314, which lies around 200 light-years away from Earth. The planet completes one rotation around its parent star in 23 days, since it is located very close to its surface. By comparison, Mercury needs 88 days to spin around the Sun once.

The study indicates that average temperatures on KOI-314c may be around 105 degrees Celsius (220 ºF), too hot for life such as that found here on Earth to survive. In addition, this planet is only 30 percent denser than water, meaning that its hydrogen and helium atmosphere is probably several hundred miles thick.

One possible explanation for its current appearance is that it may have developed as a mini-Neptune-class planet, but lost a large part of its atmosphere due to its close proximity to KOI-314. In all likelihood, the planet is tidally-locked to its star, like the Moon is to Earth.

KOI-314c is accompanied in its orbit around the red dwarf by exoplanet KOI-314b, which flies even closer to the star. Though the two worlds are about the same size, the innermost planet is roughly four times denser than Earth, and needs just 13 days to complete a full orbit around its parent star.

Scientists were able to infer the densities and masses of both worlds by analyzing how they influenced each other as they completed their orbits. “Kepler saw two planets transiting in front of the same star over and over again,” explains researcher David Nesvorny, the second author of the new study.

“By measuring the times at which these transits occurred very carefully, we were able to discover that the two planets are locked in an intricate dance of tiny wobbles giving away their masses,” adds Nesvornym who holds an appointment with the Southwest Research Institute (SwRI).