Milky Way ‘beacon’ helps aliens phone home
Scientists searching for life beyond Earth say centre of galaxy is the perfect place for a transmitter
‘If an advanced civilisation wanted to put in a beacon, the galactic centre would be a good place to do it’
ALIENS might have placed a beacon in the centre of the Milky Way, in the hope that another civilisation may spot it, scientists believe.
The Breakthrough Listen project, set up in 2015 with the help of the late Prof Stephen Hawking, is hunting for signs of advanced extraterrestrial races.
Researchers have turned their telescopes to the heart of the galaxy, in the hope that if civilisations were trying to communicate they would pick an obvious focal point.
In cities, such gathering locations are known as Schelling points; examples in London would include Buckingham Palace and the “Big Ben” clock tower at the Palace of Westminster. Scientists believe galactic centres could act as Schelling points for civilisations that cannot communicate among themselves.
They believe an advanced civilisation may have placed a powerful, intergalactic transmitter in the core of the galaxy, perhaps powered by the supermassive black hole at the heart of the Milky Way.
“The galactic centre is the subject of a very specific and concerted campaign with all of our facilities,” said Dr Andrew Siemion, of the University of California, the principal investigator.
“If you and I made an arrangement to meet in New York City on a particular day, but didn’t decide on a particular time or a place, we might both choose noon at the Empire State Building or the Statue of Liberty,” he told a meeting of the AAAS (American Association for the Advancement of Science) in Seattle.
“If an advanced civilisation anywhere in the Milky Way wanted to put a beacon somewhere … the galactic centre would be a good place to do it.”
Breakthrough Listen, based at the university’s Berkeley SETI (search for extraterrestrial intelligence) centre, is supported by a $100million (£77million) grant from Yuri Milner, the Russian billionaire.
Yesterday the team released nearly two petabytes, or one million gigabytes, of data, with members of the public encouraged to sift through it.
“For the whole of human history, we had a limited amount of data to search for life beyond Earth. So, all we could do was speculate,” said Mr Milner. “Now, as we are getting a lot of data, we can do real science – and, with making this data available to the general public, so can anyone who wants to know the answer to this deep question.”
The project uses telescopes across the globe to listen for radio signals.
Though many scientists think the first “aliens” to be found will be tiny bacterial species living under the surface of Mars, or in the frozen oceans of moons such as Titan, which orbits Saturn, Dr Siemion believes “techno-signatures” will be our first hint of life outside Earth. “There are two horses in the race to find life beyond Earth,” he said. “The first is the search for chemical signatures from planets and the second is the search for extraterrestrial intelligence. Intelligent life has the edge, as it can detect technologies like ours across the entire galaxy, and … beyond ours. “Searches for simple forms of life are limited to our solar system and a few nearby stars, and we can never be sure that methane or similar chemicals which we detect are really produced by living things. “It just comes down to statistics. Basic life may be very common, but we are much less likely to find it.” Asked if he believed intelligent alien life existed, he said: “Absolutely, yeah.” The project has also been searching for planetary systems that might be able to see Earth. Scientists spot exoplanets – those outside the Solar System – by looking for a telltale dimming in a star as a world orbits in front.
Telescopes have been turned to an area of the galaxy where an advanced alien race might use the same technique to see Earth transiting the Sun.
“Are there other civilisations that are, themselves, looking for extrasolar planets? Might they have discovered the Earth by watching the Earth pass in front of our Sun?” asked Dr Siemion.
“Perhaps they … learnt that it hosts a technologically capable being.
“We call that region of the sky the Earth transit zone. And there’s long been a suggestion in the field of study that perhaps this particular sort of patch of sky, where other stars could see the Earth transit the Sun, would be a very interesting place to conduct SETI searches.”