So far, humanity has not been able to discover any life form or any habitable planet so far. While there have been many UFO sightings as well cases of alleged abductions by aliens, we still haven’t been able to establish a solidly full-fledged and real contact with any sentient species from other planets or able to find a trace of life anywhere in the universe.
There are many theories that state why this has not happened yet. One of them states that occurrence of life requires just the right factors and conditions to come together at the right time, which holds a one in a billionth chance. The odds are so narrow and low that even if a planet would exist in a solar system’s Goldy Locks Zone or the habitable zone where there is a perfect balance of temperature and moisture, it can get obliterated by dangerous cosmic phenomena such as asteroids or gamma-ray bursts. As a result, the microbial or primitive life on these planets is destroyed, let alone having any possibility of it blossoming into a sentient civilization.
However, what is more, interesting is the theory of a Cosmic Filter, where sentient life forms on a habitable planet reach a level of advancement in their civilization, but get destroyed due to some closely related factor such as planetary pollution, war, or the spread of A.I that destroys that species.
If you think these theories are quite pessimistic and do not offer any hope to enthusiasts looking for alien life, this one might give you some relief, but won’t raise your hopes. Some scientists hold the opinion that intelligent life forms have already discovered humanity. However, we are so primitive to them, that they won’t even bother establishing contact with us.
Eminent scientists like Dr. Stephen Hawking and Dr. Michio Kaku opines that humanity would be committing mass suicide by actively trying to contact aliens, as they will ravage humanity and Earth in their search for extra resources.
The ‘Wow Signal‘ received in the year 1977 on the Big Ear radio, raises hopes of extraterrestrial life enthusiasts. The 72-second message has been calculated to have come from the constellation of Sagittarius likely and is the strongest contender for an extraterrestrial radio signal. Let us hope that either humanity can discover life on Gliese 581g, a recently discovered potentially habitable planet or some alien civilization finds the Pioneer plaques on Pioneer 10 and 11 while humanity still lives.