Researchers Discover Gigantic 'Super-Puff' Exoplanets With the Density of Cotton Candy
There are plenty of things to be thankful for on Earth: things that we often take for granted like breathable air, clean water, and the firmness of the ground beneath us. While we know that the former two aren't found throughout the universe – which is why we haven't packed up for Mars just yet – it turns out that there may be other worlds far squishier than our dense mudball. They're called "Super-Puff" planets and, as their name suggests, they're light. No, really light. If Earth is a rock, then Super Puffs are more like cotton candy or styrofoam.
The gigantic cotton candy balls are the three known exoplanets orbiting Kepler 51, a star 2600 light years from Earth, and they are massive. While some planets, like Earth, have rocky mantles and iron cores, others, like Jupiter, are composed of liquids and gasses. The Super Puffs, however, suggest an even lighter class of planets. "Though no more than several times the mass of Earth, their hydrogen/helium atmospheres are so bloated they are nearly the size of Jupiter," NASA said in a news release. "In other words, these planets might look as big and bulky as Jupiter, but are roughly a hundred times lighter in terms of mass."
NASA, ESA, and L. Hustak and J. Olmsted (STScI)
The Super Puffs were investigated and analyzed through the Hubble telescope after a team of researchers detected something odd about their atmospheric opacity, theorized to be a shroud of methane encasing the helium/hydrogen blobs. "We knew they were low density," said Jessica Libby-Roberts, a graduate student in the University of Colorado at Boulder's Department of Astrophysical and Planetary Sciences (APS), in a press release. "But when you picture a Jupiter-sized ball of cotton candy-that's really low density."
As with humans, however, the Super Puffs won't stay light forever: the two closest to Kepler 51 seem to be shedding gas at a relatively fast clip which will turn them into fairly humdrum mini-Neptunes in a few billion years, while the Kepler 51D, which is furthest from its star, will likely stay puffy.