The National Institute of Standards and Technology (NIST) will collaborate with the University of Colorado at Boulder (CU) to build and apply a custom laser-based instrument--a frequency comb--to help search for extrasolar Earth-like planets. The National Science Foundation has awarded CU a $495,000 grant for the joint project.
Frequency combs are tools for precisely measuring different frequencies of light (see the background document "Optical Frequency Combs" for more information). NIST physicist Scott Diddams, together with CU astronomer Steve Osterman and other colleagues, will design and build an unusual comb with "teeth" (individual frequencies) that are widely spaced enough for astronomical instruments to read. The new comb will be used to calibrate measurements of subtle changes in infrared starlight caused by a star wobbling from the gravitational pull of an orbiting planet. Frequency combs could be such superior calibration tools that they would make it possible to detect even tiny Earthlike planets that cause color shifts equivalent to a star wobble of just a few centimeters per second. Current astronomical instruments can detect—at best—a wobble of about 1 meter per second.
The Boulder researchers plan to take the new laser instrument to the Apache Point Observatory northeast of Las Cruces, N.M., in the spring of 2010 to integrate it with a new planet-finding experiment. For more, see the CU news release "Nobel Prize-Winning Science From Boulder Serves as Springboard for Planet Hunting."