Astronomers know that gravity from Saturn's various moons tug at the planet's rings and make spirals in them. But the catalyst for certain spiral patterns has been difficult to pin down. Now, two Cornell astronomers have determined the source: Saturn itself.
New atmospheric data for the gas giants indicates that carbon is abundant in its dazzling crystal form, they say.
Lightning storms turn methane into soot (carbon) which as it falls hardens into chunks of graphite and then diamond.
These diamond "hail stones" eventually melt into a liquid sea in the planets' hot cores, they told a conference.
The biggest diamonds would likely be about a centimetre in diameter - "big enough to put on a ring, although of course they would be uncut," says Dr Kevin Baines, of the University of Wisconsin-Madison and Nasa's Jet Propulsion Laboratory.