Narrator: This is Science Today. An instrument developed for NASA by scientists and engineers at the Lawrence Livermore National Laboratory has been taking the first-ever gamma ray data of the planet Mercury. Morgan Burks, a staff physicist at the lab, says their high resolution gamma ray spectrometer, called GeMini, is uniquely designed for this.
Burks: Mercury, being the closest planet to the sun, is extremely hot. And we're trying to send a detector there that has to operate at minus 200 degrees Celsius.
Narrator: Previously, no one thought this was possible, but GeMini is cryogenically-cooled using an innovative low-powered, miniature cooling mechanism and gold-plated infrared shielding.
Burks: The reason we use a mirror-like, gold-plated surface is that gives us a 98 percent reflectance for infrared heat and that means we can cool the detector with only a small heat load because we've rejected 98 percent of the heat that comes from Mercury planet or from the sun itself.
Narrator: GeMini was launched on the Mercury MESSENGER spacecraft in 2004 and reached its destination about two years ago. Next year, it will orbit around Mercury for a year. For Science Today, I'm Larissa Branin.