On Aug. 15, the news broke that a Russian radio telescope detected strong signals from outer space.
The signals allegedly originated from a star 95 light-years from Earth. Just to clarify, this means that the signal would have left the star or, potentially, an orbiting planet, 95 years ago. Radio waves — as do any electromagnetic wave including visible light — travel in empty space at the speed of light, about 186,000 miles per second. You blink your eyes and light goes seven and a half times around the Earth.
The signal was detected last year but only made public last month. Scientists from the RATAN-600 radio antenna in Zelenchukskaya were cautious, but still believed the source deserved permanent monitoring. The signal seems to be isotropic, that is, beamed with the same power in all directions. For this to happen, and assuming it came from an intelligent source, the responsible civilization would have to be a Kardashev Type II, a kind of civilization with a technology way more advanced than our own. We are still a Kardashev Type I (there is some debate about the scale), capable of harnessing the energy that reaches us from our star (the sun). A Type II is capable of harnessing the energy of the entire star, for example, by encompassing the whole star with a device that can efficiently absorb a large fraction of its enormous radiation.
It would be amazing, indeed, if such an advanced civilization existed not too far away from us.
The Search for Extraterrestrial Intelligence initiative, or SETI, has scanned the skies for more than 50 years in search of such signals. Carl Sagan wrote an inspiring novel, Contact, about such search, which became a blockbuster movie starring Jodie Foster and Matthew McConaughey. The question, always present as we ponder the existence of other intelligent beings in the cosmos, is whether such beings are benevolent (as in the case of Sagan's book) or malevolent, as in so many sci-fi movies. We want to know if we are alone, but we also need to be careful not to attract some destructive colonizing force to our living planet.
SETI is like a long-odds lottery; there's a tiny chance of winning but if you never play you are guaranteed never to win. As Jill Tarter, former head of SETI, liked to say, we only find if we look. Last year, Russian billionaire Yuri Milner gave SETI a $100 million grant to keep on looking. He's betting high on it.
There are many barriers to finding signals from intelligent aliens, some technological and others more fundamental. Even assuming that other intelligent and technological species exist (after all, we can measure animal intelligence in many species but not necessarily related to building complex technological devices capable of interstellar communication), they may be behind us, or we may not know which frequency to tune our antennas to listen to them, or their signals may miss us, or they may not have any interest in communicating with strangers.
In any case, as many suspected, the Russian signal turned out to be a dud. A few days ago, the Russian news agency TASS announced that the signal came from an old Russian military satellite. Many scientists had predicted this would be the case. The planet known to orbit the star is Neptune-sized, orbiting it way too close for life as we know it. But maybe there could be a smaller planet we haven't seen yet? The signal was also not very impressive. Eric Korpela, from UC Berkeley, downplayed the signal from the beginning, stating that the case for it as originating from an intelligent civilization was quite weak.
Still, the TASS announcement is sure to spice up loads of conspiracy theories. Many people are convinced of a cover-up by the government about the existence of intelligent extraterrestrials. This persistent belief could spring from a combination of general mistrust in the government and a profound need to know whether we are alone or not.
To borrow from the title of physicist Paul Davies' book on the topic, the eerie silence is what disturbs us.
Not knowing the answer for such an essential question feeds the imagination. We need to know whether we are the only intelligent species out there. The implications are profound. If we are this unique, the stakes suddenly become much higher. We become guardians of life, of the galaxy, the coalescence of matter at its highest complexity in the cosmos (or at least in our galaxy). That's quite a ponderous take on humanity — and should incite a brand new ethics, a cosmic ethics of life preservation that starts right here on Earth.
However, we must remember that even if there are other smart beings out there, in practice we remain alone. Interstellar travel is a true scientific challenge, one that may take millennia to crack, or that can't be cracked at all.
Maybe, in its wisdom, nature knew this all along — putting intelligent beings so far away from one another that each needs to come to grips with its role. It's sure taking us quite a long while to turn the page on our relation with life and accept this new role. If ETs are listening, they may very well be going through the same existential dilemmas, trying to figure out how to deal with their problems without the help of some god-like alien savior. Maybe this is the important lesson here. Sure, we should keep on listening. But we should also understand our role as guardians of this very rare place where life of all kinds abounds. At least as long as we let it.
Marcelo Gleiser is a theoretical physicist and cosmologist — and a professor of natural philosophy, physics and astronomy at Dartmouth College. He is the co-founder of 13.7 and an active promoter of science to the general public. His latest book is The Simple Beauty of the Unexpected: A Natural Philosopher's Quest for Trout and the Meaning of Everything. You can keep up with Marcelo on Facebook and Twitter: @mgleiser