Are we missing signs of alien life?
They’re somewhere out there, aren’t they? In May, the Pentagon, headquarters of the United States Department of Defense, released never-before-seen files involving extraterrestrial life and unidentified aerial phenomena (previously UFOs). Held by the government for decades, the public can now comb through the documents, photos and videos(opens in new window). We get to decide for ourselves what to make of them.
Rethinking the cosmic search strategy
We use powerful telescopes and space missions to find life elsewhere, but there’s no confirmed evidence yet. Could we be looking for the wrong signals? Could we be overlooking or even dismissing the information being gathered from these distant worlds that hint at life? When scientists search for evidence of extraterrestrial life, they often face ambiguous data. They must carefully distinguish between false positives – where evidence incorrectly suggests life is present – and false negatives – where actual signs of life are missed or go undetected. An international research team explored new techniques to correctly distinguish false negatives in order not to miss signs of alien life. Their findings were published in the journal ‘Nature Astronomy’(opens in new window). “We should be aware of these false-negative results,” commented lead author Inge Loes ten Kate, astrobiology professor at the Netherlands’ Utrecht University and the University of Amsterdam, in a news release(opens in new window). “It means there are shortcomings in recognising the existence of life. These shortcomings are not yet high on the research agenda.”
Challenges in spotting aliens
We might miss signs of alien life because those traces have faded over time, are too hard to spot or our detection technology just isn’t advanced enough to find them yet. This is how false negative results may occur. The researchers highlight a common bias: astrobiologists spend more time avoiding false positives – mistakenly claiming to find life due to data or instrument errors – than they do addressing false negatives, where signs of life go completely unnoticed. “We therefore advocate for the development of a targeted research strategy that systematically addresses these risks, in which we must combine laboratory experiments with modelling research and fieldwork,” stated ten Kate. “Space missions and instruments are designed to detect potential signs of life, but the risk of overlooking something is not taken into account. The search for signs of life should go hand in hand with better-defined questions and testable hypotheses to justify specific measurement or observation targets.” Using AI to identify patterns offers a highly effective approach to this challenge. “Because then you might well uncover things that we would never be able to see on our own. And with new observations, you can then work out how and where they fit into such a pattern,” she added. The question is how to investigate something that remains hidden. “That question goes to the heart of our problem, because we tend to look for things we already know,” concluded ten Kate. “We therefore need to understand very clearly what kind of life is possible in a particular place, what the conditions for that life are, and how we can recognise the traces of that life. And even then, we might overlook things.”
