Scientists warn public on alien communication

If aliens call, what should we say? Scientists are turning to the public to ask how — and if — we should reply to intelligent extraterrestrial life. It could alter the course of history. For decades, the most powerful telescopes on Earth have listened to the vast cosmos for signs of life. So far, scientists have heard nothing but silence. But, as our technology improves, the search is accelerating. Now, scientists have stopped to think: if we do receive a message from complex alien life, how should we respond? Should we reply at all? To find out, the UK Seti Research Network (UKSRN) has launched the largest-ever survey of public attitudes towards alien contact, including questions about who should have the authority to respond, and what the message should contain. For ideas, we can look to humanity’s past efforts to talk to aliens. In 1974, a group of scientists sent the Arecibo message to a cluster of stars called M13. The radio message contained a graphic of our solar system and a human figure. But don’t expect a reply soon: M13 is 25,000 light years away. Next year, another organisation, METI International, plans to beam signals with the atomic numbers of different elements in the periodic table. But the UKSRN thinks it could be dangerous for a technologically young civilisation like ours to broadcast our existence across the universe. Any alien race able to reach Earth, Stephen Hawking argued in 2016, would be drastically more advanced than humanity. And it’s unlikely they would come all this way just to say hello. “Meeting an advanced civilisation could be like Native Americans encountering Columbus. That didn’t turn out so well,” the physicist warned. A year before that, a group of scientists — including SpaceX founder Elon Musk — insisted that “a worldwide scientific, political and humanitarian discussion must occur before any message is sent”. Or is this a waste of time? Are we, in fact, alone? Last month, the Breakthrough Listen project revealed it had found nothing after eavesdropping on more than 1,000 solar systems within 160 light years of Earth. But, due to the sheer size of our galaxy, astronomers say that even if there were tens of quintillions of intelligent civilisations evenly distributed around the Milky Way, the project would still have heard nothing. We haven’t yet scratched the surface. Reach for the stars? How should we respond to an alien message? Perhaps not at all. It could be from a race of nomadic aliens — their home destroyed — scouring the galaxy for a habitable planet to colonise. A civilisation that advanced might see us as a pest infestation. But we have been beaming high-frequency radio and TV into space for 100 years. If aliens are looking, they can find us. So, why not send a democratic, positive message to the stars from all of humanity? It is an historic opportunity. KeywordsLight years - A unit of measurement equal to the distance that light travels in one year, which is 9.4607 times 1012 km. That's nearly 6 million million miles!