Astronomers Find a ‘Super-Puff’ Exoplanet That’s Even Stranger Than Expected

One of the fluffiest exoplanets we’ve ever come across in the Milky Way is raising all sorts of questions about planet formation.

Transcript

00:00One of the fluffiest planets we've ever come across is raising all sorts of questions about

00:09planet formation. This big blob of cotton candy in space, WASP107b, is what's known as a super

00:17puff planet. It's about as big as Jupiter, but 10 times lighter. That's because it has super low

00:23density. Now, astronomers believe its core is even less massive than previously thought.

00:28Scientists at the University of Montreal made the calculations using four years of observations

00:34taken from the Keck Observatory. Measuring how much the planet's gravity affected its host star,

00:40they discovered its solid core was only 4.6 times the mass of Earth, meaning its fluffy atmosphere

00:47makes up at least 85 percent of its mass. But now, astronomers are left with more questions, such as

00:53how could a planet like this keep all that gas from escaping, being so close to its star? And,

00:59how could a planet with such a tiny core gather up all that gas in the first place? For now,

01:05it's believed WASP107b formed further out, where gas is cold enough that it can be accumulated quickly.

01:12Then, that process was likely interrupted by an interaction with another planet in the system,

01:18which flung it inward towards the star. The research, published in the Astronomical Journal,

01:22may give scientists a better idea of how planets form in general.