This spring, the Allen Telescope Array, or ATA, a cluster of 42 radio astronomy dishes about 300 miles north of San Francisco, became the latest science casualty of California’s budget crisis, when the University of California, Berkeley, pulled its funding for the project. The ATA had operated as a listening station for alien transmissions for four years, and its loss was to be a significant hit to our hopes of finding little green men.
Within a few months, however, the Search for Extraterrestrial Intelligence Institute (which ran the ATA with UC) managed to raise $200,000 through public donations, enough to keep the telescope going for the near future.
With some luck (and money), the ATA will continue its search for extraterrestrial civilizations at least through 2016, when there will be a new, much bigger kid on the block: the $2.1 billion Square Kilometre Array, or SKA, a collaboration among 70 organizations in 20 countries. The SKA is essentially a bigger, more advanced version of the ATA. The site is undecided, but the blueprints call for thousands of dishes—each wider and more powerful than those of the ATA—to be spread over an area more than 1,800 miles wide. The dishes can point and turn in unison, picking up radio waves from vast tracts of sky and relaying the ATA to computing facilities with the processing power of 1 billion PCs. The SKA will be 50 times as sensitive as its predecessor, capable of registering booming “we are here” broadcasts from civilizations halfway across the Milky Way. It could also detect faint alien signals leaking into space, akin to those from airport radar or TV broadcast towers. In other words, the SKA could hear ETs even when they are not trying to call us.
All this for aliens? Not exactly. Unlike the ATA, which was devoted primarily to finding intelligent life, the SKA will help study general relativity, star and planet formation, and more. The ET hunt is just one of many aims. Lazio, the SKA chief project scientist, explains that the varied goals do not conflict: The same signals gathered while studying stars can be parsed for alien messages. “Anytime you point dishes at the sky, you get data that you might as well scan for ET civilizations,” he says. The SKA is also protected against penny-pinching. “The money is coming from many countries,” Lazio says, “so it’s less likely to just disappear.”