"Saturn On Steroids" Has Massive and Seemingly Impossible Rings
There's a celestial body 400 light years away that looks a lot like Saturn, except its rings are so large that they shouldn't be able to exist. Its official title is J1407b, but it's been informally dubbed Saturn on steroids.
The Impossible Planet
Whoa, whoa, slow down. We're not actually sure that J1407b is a planet. It could be a brown dwarf, which is technically a star but really sits somewhere between failed star and enormous gas giant. Either way, it's the ring system that has scientists talking. It's 75 million miles in diameter, which is about 200 times larger than the rings of Saturn. If J1407b was in our own solar system, it would appear in our sky many times larger than our own moon (as astronomer Matthew Kenworthy depicted in this image). The problem is that as J1407b travels in its elliptical orbit, it gets dangerously close to its host star—so close that its rings should break apart due to the forces of gravity. But they don't. Astronomers weren't sure why.
Uncovering The Mystery
In 2016, Steven Rieder and the aforementioned Matthew Kenworthy published a paper in the journal Astronomy & Astrophysics showing that they may have cracked the enigma. Rieder, Kenworthy, and their team ran a variety of computer simulations that tested all the different possible ways J1407b and its rings might move. They realized that the rings could stay stable if they spun counterclockwise while the planet/star rotated clockwise. If they both move in the same direction, everything breaks apart. But that just leads to another mystery: they can't figure out how the two ended up spinning in opposite directions in the first place.