Mona Delitsky of California Specialty Engineering in Flintridge, and Kevin Baines of the University of Wisconsin-Madison, who presented their theory at a recent planetary conference in Denver, Colorado, said they are “pretty certain” of what’s happening in those planets.

Essentially, the hypothesis goes, lightning in the upper atmospheres of Jupiter and Saturn separates carbon atoms from molecules of methane, which then stick to each other, forming particles of carbon soot.

Those bits drifts down through more dense layers of hydrogen gas and liquids, getting exposed to higher pressures and temperatures as it gets closer to the planets’ rocky cores.

But diamonds aren’t forever on Saturn and Jupiter. The combination of high temperature and pressure compresses the soot into graphite, then into diamonds, which then melt into diamond raindrops as soon as they reach 8,000 degrees Celsius.

“If you had a robot there, it would sit there and collect diamonds raining down,” Baines was quoted as saying. Once they fall into the core, however, they melt and form an ocean of liquid diamond, Baines explained.

Researches had previously linked diamond cores to Uranus and Neptune but this is the first time their two neighbours have been thought to have the same.

“This kind of study shows that we are still far from understanding the composition and structure of Jupiter and Saturn, two planets which are respectively about 300 and 100 times the mass of our Earth and were crucial players when the whole Solar System formed,” Tristan Guillot, planetary researcher at the Observatoire de la Cote d’Azur in France, told CNN.

Image from Wikimedia Commons.