Mark Buchanan, Washington Post: “Attempting to communicate with extraterrestrials, if they do exist, could be extremely dangerous for us. We need to figure out whether it’s wise – or safe – and how to handle such attempts in an organized manner. Some scientific circles have already been debating questions around whether to try to contact other civilizations. It’s a topic of profound importance for the entire planet. For 60 years, scientists have been searching with radio telescopes, listening in for possible signals coming from other civilizations on planets orbiting distant stars… The search for aliens has reached a stage of technological sophistication and associated risk that it needs strict regulation at national and international levels. Without oversight, even one person – with access to powerful transmitting technology – could take actions affecting the future of the entire planet. That’s because any aliens we ultimately encounter will likely be far more technologically advanced than we are, for a simple reason: Most stars in our galaxy are much older than the sun. If civilizations arise fairly frequently on some planets, then there ought to be many civilizations in our galaxy millions of years more advanced than our own.”

“Many of these would likely have taken significant steps to begin exploring and possibly colonizing the galaxy. Hence, it’s a profound mystery – known as the Fermi Paradox, after the Italian physicist Enrico Fermi – why we haven’t yet seen any such aliens. Many resolutions of the paradox have been proposed, among them the suggestion that all civilizations, once reaching sufficient technological capacity, eventually destroy themselves. Or perhaps aliens are so alien and unlike humans that we simply cannot interact with them. More alarming is the possibility that alien civilizations are remaining out of contact because they know something: that sending out signals is catastrophically risky. Our history on Earth has given us many examples of what can happen when civilizations with unequal technology meet – generally, the technologically more advanced has destroyed or enslaved the other. A cosmic version of this reality might have convinced many alien civilizations to remain silent. Exposing yourself is an invitation to be preyed upon and devoured.”