A newly discovered planet became the lightest planet to have its mass and physical size measured. While it weighs as much as Earth, it is gassier, according to a press release.
KOI-314c is a new planet discovered by Harvard-Smithsonian Center for Astrophysics (CfA) researchers. This newly found planet is the lightest planet to have its mass and physical size measured. Researchers found that its mass is similar to that of the Earth but it has a 60 percent larger diameter with a very thick, gaseous atmosphere.
"This planet might have the same mass as Earth, but it is certainly not Earth-like," says David Kipping of the Harvard-Smithsonian Center for Astrophysics (CfA), lead author of the discovery in a statement. "It proves that there is no clear dividing line between rocky worlds like Earth and fluffier planets like water worlds or gas giants."
Using NASA's Kepler spacecraft, the international team of researchers was able to deduce more characteristics of this planet. They found that KOI-314c orbits a dim, red dwarf star located approximately 200 light-years away, making it the first Earth-mass planet that transits or crosses in front of its host star. It circles its star every 23 days. Temperatures on the planet range around 104°C.
Owing to that fact that KOI-314c is only 30 percent denser than water, researchers speculate that it has hundreds of miles of thick atmosphere rich in hydrogen and helium. Researchers also suggest that this planet may have been similar to Neptune but lost its reserves of gas a long time back.
"When we noticed this planet showed transit timing variations, the signature was clearly due to the other planet in the system and not a moon. At first we were disappointed it wasn't a moon but then we soon realized it was an extraordinary measurement," said Kipping.
Measuring the weight of small planets can be quite challenging since measuring the tiny wobbles of the parent star of a planet as small as Earth is very difficult. The closest scientists have gotten to measuring an Earth-like exoplanet is Kepler-78b, a planet that weighed 70 percent more than Earth.
To measure KOI-314c, researchers used a technique known as transit timing variations. This technique can only be used when two planets are found orbiting the same star.
"Rather than looking for a wobbling star, we essentially look for a wobbling planet," explains second author David Nesvorny of the Southwest Research Institute (SwRI). "Kepler saw two planets transiting in front of the same star over and over again. 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."
The other planet used in the study was the KOI-314b. It is of the same size as KOI-314c but is much denser and weighs four times more than our planet.
