Molten and solid diamonds could be hidden in space
There is something in the sky with diamonds, and not only a girl named Lucy.
Research suggests solid diamonds are scattered deep inside both Jupiter and Saturn. Planetary experts have long thought that Uranus and Neptune boast diamonds in their depths, but no one knew whether the same was true for their solar-system neighbors. Now there's evidence Jupiter and Saturn harbor hidden treasure, scientists said Tuesday at a meeting in Denver.
“We don't want to give people the impression that we have a Titanic-sized diamondberg floating around,” says planetary scientist Mona Delitsky of California Specialty Engineering, a consulting firm. “We're thinking they're more like something you can hold in your hand.”
Only the outer parts of the planets would contain solid diamonds. Closer to the planets' core, temperatures are so high that the gems would melt into droplets of liquid diamond, a mysterious substance that may have some of the internal structure of the familiar jewel. That could lead to diamond “rain,” which could form small pools of molten diamond. On Neptune and Uranus, lower temperatures mean diamonds stay solid.
“Diamonds are forever on Uranus and Neptune, but not on Jupiter and Saturn,” quips Delitsky's colleague Kevin Baines of the University of Wisconsin-Madison.
Any diamonds on Jupiter and Saturn originated with a decidedly less glamorous material: methane gas, which wafts out of landfills and sewers on Earth and is found in the atmosphere on the solar system's two biggest planets. During storms, lightning blasts apart some of the methane on both Jupiter and Saturn, creating fluffy, jet-black soot much like the stuff that floats out of a fireplace.
Delitsky and Baines decided to trace the fate of that soot as it sinks. They relied in part on calculations by other scientists of conditions deep inside the planets. They took advantage of recent data showing how carbon, “the building block of both soot and diamonds,” reacts to high temperatures and pressures.
Their work shows that the soot first turns into graphite, a form of carbon used in pencils. As the bits of graphite journey to the center of the planet, the pressure and temperature squeeze and heat them into specks of solid diamond in a sea of helium and hydrogen. That transformation takes place at 5,000 degrees on Saturn and nearly 7,000 degrees on Jupiter.