If you spend $100 million to listen for aliens, you probably want to see results pretty quickly, right? That’s how much Russian billionaire Yuri Milner and a few others invested in 2015 in the Breakthrough Listen project – a 10-year program that listens for unusual signals that could be from extra-terrestrials. With two years gone, the project felt it needed to give an update on its website and in the Astrophysical Journal. So far, it has identified 11 signals that are unusual enough to take a closer look. Aliens?
The Breakthrough Listen project is managed by a team at the University of California, Berkeley, SETI Research Center and uses the Parkes Telescope in Australia, the Green Bank Telescope in West Virginia and the Automated Planet Finder optical telescope at Lick Observatory in California to collect radio signal data – a LOT of radio signal data. In just two years, the project has accumulated eight petabytes (8 million gigabytes) of data from observations of just 692 stars that have been designated as possible candidates for alien life – a total of 1709 stars have been selected for the project. Each is observed for three five-minute periods and the stars fall into one of two categories: a) within 16 light years from our Sun or b) up to 163 light years away.
If the Breakthrough Listen project sounds familiar, it’s the group that spotted the irregular dimming of Tabby’s Star. It has since been determined that the dimming is not due to a Dyson sphere or other alien activity but is caused by comet fragments interfering with signals.
What about the 11 other signals that didn’t fit the usual pattern? The Green Bank Telescope looks for signals in frequencies ranging from 1.1 to 1.9 GHz where artificial ones can be distinguished from natural sources like pulsars, quasars, radio galaxies and Cosmic Microwave Background – the electromagnetic radiation left over from the time of recombination in Big Bang cosmology (and a great name for a band). The eleven events rose above the threshold for significance and ranged from to 25.4 to 3376.9 SNR (Signal-to-Noise Ratio).
Although the search has not yet detected a convincing signal from extraterrestrial intelligence, these are early days. The work that has been completed so far provides a launch pad for deeper and more comprehensive analysis to come.
Dr. Andrew Siemion, Director of the BSRC, said in the Breakthrough Listen press release that it’s too early to tell. They will be developing new algorithms based on current data and releasing new reports every six months. Will they really let us know if they find an alien life signal?
Russian billionaire Yuri Milner didn’t spend $100 million for nothing.