Far Out Forecast: Diamond Rain

Scientists have found that diamonds may be raining down on Saturn and Jupiter. But it’s not just a light sprinkle of tiny precious flecks; rather, 1,000 tonnes of large diamonds could be inundating Saturn every year. And by big, we’re talking jewels Hollywood celebrities like Elizabeth Taylor would have been “proud to wear,” according to University of Wisconsin-Madison’s Dr. Kevin Baines. The BBC explains the science behind this phenomenon:

New atmospheric data for the gas giants indicates that carbon is abundant in its dazzling crystal form, [scientists] 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 [Baines]…

Baines presented his unpublished findings at the annual meeting of the Division for Planetary Sciences of the American Astronomical Society in Denver, Colorado, alongside his co-author Mona Delitsky, from California Speciality Engineering.

Uranus and Neptune have long been thought to harbour gemstones. But Saturn and Jupiter were not thought to have suitable atmospheres.

They concluded that stable crystals of diamond will “hail down over a huge region” of Saturn in particular.

“It all begins in the upper atmosphere, in the thunderstorm alleys, where lightning turns methane into soot,” said Baines.

“As the soot falls, the pressure on it increases. And after about 1,000 miles it turns to graphite – the sheet-like form of carbon you find in pencils.”

By a depth of 6,000km, these chunks of falling graphite toughen into diamonds – strong and unreactive.

These continue to fall for another 30,000km – “about two-and-a-half Earth-spans” says Baines.

“Once you get down to those extreme depths, the pressure and temperature is so hellish, there’s no way the diamonds could remain solid.

…”Diamonds aren’t forever on Saturn and Jupiter. But they are on Uranus and Neptune, which are colder at their cores,” says Baines.

It should be noted that Baines and Delitsky’s findings haven’t been peer reviewed yet, but experts in the science community are not ruling out the possibility of diamond rain. Baines, however, states confidently, “It all boils down to the chemistry. And we think we’re pretty certain.”

—Posted by Natasha Hakimi