A new type of super-Earth, 17 times more massive than our home world, has lately been recognized by astronomers. Researchers are calling this alien world a "Godfather planet."
Astronomers mostly believed such giant rocky worlds were impossible. Traditional thinking held that worlds this size would attract so much hydrogen gas, they would quickly transform into gas giants, similar to Jupiter and Saturn.
Kepler-10c is located 560 light-years from Earth, in the direction of the constellation Draco. This mega-Earth orbits its companion star once every 45 Earth days. That planetary family also features Kepler 10-b, a "lava world" three times more massive than the Earth. This body orbits so close to its sun that a year on the magma-covered planet lasts just 20 hours.
The Godfather planet was discovered using the Kepler Spacecraft, launched in 2009.
"We were very surprised when we realized what we had found," Xavier Dumusque, the Harvard-Smithsonian Center for Astrophysics (CfA) astronomer who discovered the planet, said.
At first, researchers believed the body, with a diameter of 18,000 miles (2.3 times as wide as Earth) was a mini-Neptune, mostly made of gases. Planets in this class are much less dense than our home world, exhibiting a low mass for their size. When astronomers used the Telescopio Nazionale Galileo observatory in the Canary Islands to measure the mass of the planet, they found the alien world was 17 times as massive as the Earth.
Astronomer Lars Buchhave of the CfA noted a correlation between the period (length of year) of worlds and how quickly they transform into gas giants. This work suggests such giant, rocky worlds may not be rare.
The Kepler 10 system is extremely old, having formed just three billion years after the Big Bang. Heavy elements were thought to be rare then, but this planet shows materials were available early on to form such giant worlds.
Announcement of the massive world was presented at a meeting of the American Astronomical Society (AAS).
Given its massive size, Kepler-10c would easily be able to hold on to a thick atmosphere and liquid water. Such conditions could make this massive world one of the prime candidates on which alien life may have arisen. Tremendous gravity on Kepler-10c could mean beings there evolved stupendous strength, making them potentially far stronger than any being on Earth.
"Finding Kepler-10c tells us that rocky planets could form much earlier than we thought. And if you can make rocks, you can make life," Dimitar Sasselov, Harvard University's Origins of Life Initiative director, said.
Which begs the question - if there are aliens on this "Godfather planet," will they, one day, make the human race "an offer [we] can't refuse?"
