Benedetti and Jeanloz squeezed liquid methane to make diamond dust. The liquid methane, cooled with liquid nitrogen, was placed in the diamond anvil cell and squeezed to 10 and 50 billion pascals (gigapascals), or about 100,000-500,000 times atmospheric pressure on Earth. Next, the researchers heated the methane with an infrared laser to 3,000 Kelvin (5,400 degrees Fahrenheit). The laser caused the methane to turn black because of the diamonds created. The black diamond specks float in a clear hydrocarbon liquid melted by the laser.
Jupiter and Saturn may also contain diamonds produced under such conditions, though they contain proportionately less methane than Neptune and Uranus. Neptune and Uranus are estimated to contain 10 to 15 percent methane under an outer atmosphere of hydrogen and helium.
What's in the sky-Let's hope for a clear sky Nov. 16 for the Leonid meteor shower. Light from the gibbous Moon will wash out some of the meteors.
Louis Varricchio lives in Vermont. He was a NASA senior science writer and a freelance science reporter for Public Radio International. He is a part of the NASA/JPL Solar System Ambassador program in Vermont and a senior member of the U.S. Civil Air Patrol, a U.S.Air Force auxiliary.