If there is life on other planets, a laser frequency comb developed at Commerce's National Institute of Standards and Technology (NIST) may help find it.

Such a comb—a tool for precisely measuring frequencies, or colors, of light—has for the first time been used to calibrate measurements of starlight from stars other than the Sun. The good results suggest combs will eventually fulfill their potential to boost the search for Earth-like planets to a new level.

The comb was transported to the Texas mountains to calibrate a light analyzing instrument called a spectrograph at the Hobby-Eberly telescope. A University of Colorado Boulder (CU) astronomer and Pennsylvania State University students and astronomers collaborated on the project.

“The comb worked great,” says NIST physicist Scott Diddams. “In a few days, it enabled measurement precision comparable to the very best achieved in the same wavelength range with much more established techniques—and we hope the comb will do much better as the new technique is perfected.”

The NIST comb calibrated measurements of infrared starlight. This type of light is predominantly emitted by M dwarf stars, which are plentiful in Earth’s part of the galaxy and might have orbiting planets suitable to life.