We are constantly empty in search of alien life. What this might mean – What happens next
Since ancient times, human beings have been thinking about the existence of life outside the earth. In the 1900s, scientists began to actively seek evidence. Needless to say, we still haven’t found anything. Although it’s only decades and technology is developing every day, what if we continue to go home empty-handed?
In a study published Monday in the Journal of Astronomy, an international team of researchers believed that what we found could still have a deeper understanding of the issue. The study shows that identifying a certain number of inanimate exoplanets can allow scientists to confidently determine whether life outside Earth is common or rare.
Specifically, researchers used advanced statistical models to demonstrate that if evidence of life is not found in 40 to 80 exoplanets, we can infer that less than 10 to 20% of the cosmic host life span. While this doesn’t seem impressive, it will represent an upper limit of potential life beyond the planet, a limitation we lack at the moment. But that is to say, even 10% of the planets in the Milky Way have reached at least 10 billion worlds.
“This result will be a turning point,” said Daniel Angerhausen, astrobiologist in Zurich Eth Zurich, a lead author of the study. “Even if we don’t find life, we will eventually be able to quantify the rare (or common) of having detectable biosignatures.”
Biosignatures are indicators of biological processes, and therefore, signs of life we know about. It is also worth noting that all the planet-like bodies outside our solar system are technically called exoplanets, and planets refer to eight bodies orbiting our sun (although this may change soon). However, some scientists believe that exoplanets are planets for simplicity.
The results of this study are in the context of upcoming missions to study biosignatures on Earth-like exoplanets, such as NASA’s Habitable World Observatory (HWO) and the European-led large interferometer (Life). These missions may investigate enough exoplanets to reach the conclusions outlined in the study.
However, the biggest warning of statistical modeling with Angerhausen and his team is that it depends to a large extent on the accuracy of the scientist’s personal observations. Errors such as false negative tests may significantly skew towards broader results. Even the possibility of instruments lacking biosignatures can undermine the reliability of the universality of claims to alien life.
“It’s not just how many planets we observe, it’s about how confident we are to see or not see what we are looking for,” explained Angerhausen, who works with SETI Institute. “If we are not careful and overconfident in our ability to identify life, even a large number of investigations can lead to misleading results.” In other words, the upcoming investigation should carefully consider the uncertainty and bias in its approach.
Ultimately, researchers highlight the fact that all scientific results (even disappointing results) can teach us valuable lessons if we accept uncertainty and ask the right questions.
