TV switch-over triggers rush to see rare stars

摘要

US skies are clearerthan usual after the switch in June from analogue to digital TV freed up a chunk of the radio spectrum. Astronomers are now rushing to see what they can find before transmissions from cellphone companies and others fill the space. Prior to the switch-over, naturally occurring radio waves at frequencies between 700 and 800 megahertzrnwere obscured by analogue TV signals, preventing astronomers from investigating the universe using this band. Now a receiver has been installed at the Arecibo Observatory in Puerto Rico to take advantage of the new-found clarity.