Allen Telescope Array (ATA) under construction, aerial photograph. The ATA, an array of 350 radio telescope antennas (dish-shaped objects), will be used simultaneously for the SETI project (Search for Extra-terrestrial Intelligence) and for radio astronomy research. The ATA is in California, USA. The first 42 antennas (some seen here) were built in 2005. The full 350-antenna array is scheduled for completion by 2008. When completed, it will be one of the largest and most powerful telescopes in the world, and will greatly expand the number of stars surveyed by SETI. The seemingly random arrangement of the antennas is designed to maximise different spacings between them. The ATA was formerly the One Hectare Telescope (1hT).