Sounds impossible some may say. However, there’s a lot of carbon in the atmosphere of these planets. When some of it gets hit by lightning, it turns into graphite and is then squeezed by the enormous pressure of the atmosphere until it becomes a diamond. These diamond “hail stones” eventually melt into a liquid sea in the planets’ hot cores.
The biggest diamonds would likely be about a centimeter 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.
“The bottom line is that 1,000 tonnes of diamonds a year are being created on Saturn.
“People ask me – how can you really tell? Because there’s no way you can go and observe it.
“It all boils down to the chemistry. And we think we’re pretty certain.”