Somewhere out there in the vastness of the Cosmos, a little green fellow with pointy ears might be looking at the night sky and wondering if there is life on any other planets. While it sounds like just another scenario for sci-fi movies, the fact is that the chances are high for the hypothetical situation to actually represent a reality. In other words, the Universe could be teeming with alien life. Otherwise, why is this Universe so freaking huge?
Astronomers have been looking for signs of alien life elsewhere in the Solar System and even beyond for decades. So far, they found nothing, but they definitely shouldn’t give up hope. They have only managed to monitor a very small portion of what can be explored.
Let’s have a quick look at some of the most important clues that astronomers can have that could indicate the presence of alien life on a remote planet. However, we need to keep in mind that alien life doesn’t necessarily mean highly advanced alien civilizations, as we’ve all seen in sci-fi movies. With that out of the way, let’s cut to the chase:
The presence of liquid water
They say you can’t live without love, but water might actually be more important. Life as we know it couldn’t possibly exist without the presence of liquid water, and that includes microorganisms. Therefore, when astronomers detect the presence of water on another planet,, that’s a hint that something might be alive there. It’s not a guarantee, though, but it’s better than nothing.
The planet is located in the “Goldilocks Zone”
Our planet, such as Mars, is located in the so-called “Goldilocks Zone” of the Solar System. That’s the area where it’s neither too hot nor too cold for life to emerge. Guess what? Other solar systems in the Universe have such areas as well, and when astronomers find a planet there as well, it means that alien life could also be present.
Atmospheric composition
Analyzing the composition of the atmosphere of a planet can provide valuable insights into its potential to support alien life. In other words, the detection of certain gases such as methane, oxygen, and carbon dioxide in the atmosphere of a planet could indicate the presence of biological processes, and there’s no wonder why. These gases are usually associated with life on Earth.
A stable climate
A planet that has a stable climate has a higher chance of providing a hospitable environment for life to thrive. Factors such as minimal atmospheric turbulence, a moderate temperature range, and a stable orbit around the parent star contribute to the long-term stability of the climate of a planet.
The presence of organic molecules
Organic molecules, meaning compounds containing carbon and other elements that are essential for life, have been found in various cosmic environments, such as asteroids, comets, and the atmospheres of distant planets. If astronomers detect organic molecules on the surface of a planet or in its atmosphere, it could suggest the existence of prebiotic chemistry or even microbial life.
However, the problem of detecting alien life needs to be seen with caution and skepticism. Many factors can influence the habitability of a planet, and we also need to keep in mind that the human understanding of what constitutes life beyond our own planet is still evolving.
