29 October 2004
Vol 306, Issue 5697

About The Cover

Cover image expansion

COVER The Cosmic Background Imager, high in the Chilean Andes, carries out observations of the polarized microwave background with microkelvin sensitivity. The instrument is an array of 13 radio antennas that are cooled to 6 kelvin and mounted on a platform that can track the sky and rotate about the optical axis. See page 836. [Photo: Caltech/CBI/NSF]