The Astro-comb, an astounding advance in taking the spectra of stars, soon may allow Earthlings to know whether a small, distant planet is an ocean world, a rocky planet like our own or something completely different.

Ron Walsworth, senior physicist at the Harvard-Smithsonian Center for Astronomy, Cambridge, Mass., told of the technology he and colleagues invented, during a lecture Wednesday night in the University of Utah's Aline Wilmot Skaggs Biology Building. The free public talk, part of the U.'s Frontiers of Science lecture series, was sponsored by the College of Science and the College of Mines and Earth Science.

[Ron Walsworth lecturing at the University of Utah Wednesday night. Photo by Cory Bauman]

The energetic Walsworth charmed the hundreds in the audience, as he moved around, gesturing to show concepts like stretching of star spectra or the orbits of planets.

Those who don't remember their high-school chemistry are reminded that light can be broken into spectra. In 1672 Sir Isaac Newton created a spectrum when he sent sunlight through a prism, dividing the light into its component colors ranging from red to violet. He could not see others, infrared and ultraviolet, because they are beyond the range that can be detected by the human retina, but they were there too.