Space Diamonds: Dime a Dozen

March 5, 2008 -- Scientists have devised a way to use an infrared telescope to find diamonds in space.

Unlike the rare terrestrial varieties that sparkle in jewelry, polish hard metals and give drill bits a cutting edge, celestial diamonds are ubiquitous, though extraordinarily petite. About 25,000 of them would fit in a grain of sand.

Still, because space diamonds are made of carbon, the building block of all life on Earth, studying them may help scientists understand how carbon-rich molecules develop.

"Space diamonds are formed under very different conditions than diamonds are formed on Earth," said Louis Allamandola, with NASA's Ames Research Center in Moffett Field, Calif.

On Earth, diamonds form deep inside the planet, under high temperature and pressure. In space, the opposite conditions exist, with extremely low pressures and temperatures that dip to minus 400 degrees Fahrenheit.

The idea to look for diamonds in space literally dropped from the sky. In certain meteorites that have crashed to Earth, about three percent of the carbon inside is in the form of nanometer-sized diamonds. If the meteorites accurately reflect the composition of interstellar gas and dust, that would mean that every gram of cosmic cloud contains 100,000 trillion nanodiamonds.