Saturn has a lot of moons - and many of them are strange and inhospitable. But this might take the award for the weirdest of the lot.
New Scientist has an interesting report about Methone, a shiny white satellite orbiting within one of Saturn's rings which is literally made of fluff.
Spotted up close for the first time in 2012 by Nasa's Cassini spacecraft, Methone, named after one of the seven daughters of Titan, is a white oval-shaped moon just five kilometres across which orbits in Saturn's E ring, 120,546 miles from the planet.
It is assumed that Methone's strange shape is caused by Saturn's intense gravity, but for a moon to be distorted to that degree it would have to be about three times less dense than water.
Methone is also totally smooth, without any craters or impact scars on its surface - an oddity considering moons that small have no obvious way to fix the damage. They cannot retain an atmosphere, have little gravity and are unable to maintain geological processes - such as volcanoes - that could smooth out the scars.
So why is the moon so smooth, oval and, well, weird?
Apparently, it's made of fluff (or dust).
According to New Scientist, a report made last year at the Lunar and Planetary Science Conference showed that the density of the moon was just 300 kilograms per cubic metre.
In a report at Planetary.org, it is imagined that a well-protected space ship might hypothetically be able to fly right through it.
Despite this knowledge, scientists still aren't sure exactly what Methone is made of, or how it was formed. It's possible that ice on the surface is being levitated by electrons from the planet's radiation belt but that's still an early hypothesis.
Nasa suggests that the moon may have formed after being split from either Mimas or Enceladus, or might have once been part of a larger swarm that orbited close to the planet.
Meanwhile Cassini has moved onto other parts of the Saturn mini-system, and recently produced the first topographic map of its largest moon, Titan.