Up to this point, all efforts to search for extraterrestrial life beyond Earth have been unsuccessful.
NASA’s Voyager spacecraft is one of the rare objects from Earth to have ventured beyond the Solar System to continue exploring the mysteries of distant star systems (Image: Getty).
The Solar System has existed for over 4 billion years. If life ever emerged in our galaxy, it likely reached a level of sophistication far beyond that of humans. This civilization (if it exists) may have also discovered the technologies necessary to travel to other star systems. So, what are scientists doing to identify the clues that this civilization may have left behind?
Searching for signs of life
One of the most feasible methods for identifying the existence of extraterrestrial beings is to search for signs of any form of life beyond Earth.
To date, this is the most common approach in astronomy, targeting distant planets and star systems.
Within the limits of our current technology, humans can search for chemical compounds that constitute life in the atmosphere, analyze geological structures, or emit non-verbal forms of communication through radio or optical signals.
However, up to this point, all efforts to search for extraterrestrial life beyond Earth have been unsuccessful.
Searching for remnants left behind
When the quest for extraterrestrial life faces difficulties, scientists have come up with a novel idea: to use telescopes to search for remnants left behind.
The hypothesis is that many civilizations may have come and gone throughout our galaxy. If each civilization left some traces before disappearing, this would be the basis for us to believe in their existence.
So far, scientists have searched for everything on the surface of planets, from spacecraft wreckage to abandoned bases, and even debris. They believe that these efforts will be rewarded if there was indeed some civilization that once existed.
Searching for impacts on space and time
It’s not ruled out that extraterrestrial beings might have passed through our Solar System on rocket-powered vehicles without leaving any traces.
However, even in this case, they would undoubtedly leave some specific evidence. For example, spacecraft, no matter how advanced, must still obey Newton’s laws and release some form of exhaust into space.
Interstellar travel could also interact with the past, rather than merely passively observing the present. For instance, if they traveled past Venus thousands of years ago, we could still see their reflections through modern observatories.
In an ongoing effort, scientists and astronomers are tirelessly searching for extraterrestrial life through various methods. However, up to this point, there is still no scientific evidence precise enough to deny or confirm this possibility.