Experts have thoughts on where extraterrestrial life may be hiding if it truly exists. The search for alien life has been ongoing for decades and has still yielded no viable results.

Our best bet: Exoplanets in habitable zones

To date, our best bet for locating extraterrestrial life is looking at exoplanets in habitable zones. Nasa defines the 'Habitable Zone' as the distance from a star at which liquid water could exist on orbiting planets' surfaces. So far, astronomers have discovered around 5,000 exoplanets, some of which could support life.

Mathematical framework to locate habitable planets

In a recent study, Professor Piero Madau of astrophysics from the University of California, Santa Cruz proposes a mathematical framework that could help us locate even more habitable planets. The calculation is meant to identify the population of habitable planets within 326 light-years of our Sun. Madau suggests that within just 61 light-years of our Sun, as many as 11,000 Earth-sized exoplanets could orbit their stars' habitable zones. "The approach is based on a set of differential equations and provides a time-dependent mapping between star formation, metal enrichment, and the occurrence of exoplanets and potentially life-harboring worlds," the study reads.

The Copernican Principle

One of the biggest influencers on the study is the Copernican Principle. The principle posits that Earth is not the center of the universe and therefore not in a great position to observe the Universe. However, by using several mathematical equations, astronomers can determine which stars could point us toward biosignatures. Biosignatures comprise certain elements that are considered the building blocks of life as we know it. Typically, they consist of carbon, hydrogen, oxygen, and nitrogen, among others. Conditions have to be very particular for these elements to exist on an exoplanet. But assuming Earth is an average planet, as the study does, they should be more common than previously thought.