For 60 years now, one method has dominated astronomers' search for extraterrestrial intelligence (SETI): the use of extremely powerful receivers to try to pick up radio waves sent through space by ETs in their efforts to communicate.
In more recent decades, a second method—scanning the skies for flashes of light, sent by aliens as a signal—was introduced. But optical SETI has its limitations as well. The price of the sensors and lenses needed to detect faraway lights has been very high, and even scientists who could afford them could scan only small parts of the sky at once. Another complication: the false positives created when telescopes would pick up charged particles of radiation within the Earth's own atmosphere.
Along with changing market forces and technology, a plan by a team of American and Chinese astronomers could reportedly be the key to overcoming these obstacles. Last week, the team submitted its proposal to position dozens of telescopes at different points here on Earth. This method, called Panoramic SETI, would help weed out false positives, while allowing for a much greater field of view. Thanks to drops in price, both the light sensors and lenses involved are also much less expensive these days.
Skeptics caution that even if PanoSETI allows for broader, cheaper, and more accurate scans for flashes of light across the galaxy, there's no guarantee that ETs are out there, trying to get our attention. But as an improvement in the SETI toolkit, it's an exciting step forward in answering the age-old question of whether we're alone in the universe.