Mankind is not exploring the cosmos only to find an extraterrestrial mind, but hope has not yet been lost. Researchers are aware that there are minimal chances of finding aliens. The calculation of these chances is based on the Drake formula - seven variables that allow determining the possibility of the existence of civilizations outside the Earth.
The formula looks like this:
However, the formulas are aging, and in the equations one can always make a mistake. Drake's formula appeared almost 60 years ago, and therefore does not reflect the information that SETI researchers have been collecting and updating since the 1960s.
In a new study, scientists tried to integrate new data on exoplanets as part of the Drake equation. The question of the existence of developed alien civilizations in the Universe has always encountered three uncertainties in the formula. Scientists have long known how many stars there are, but no one could say:
- how many planets revolve around stars.
- how many planets are potentially capable of having conditions for the birth of life.
- for how long extraterrestrial civilizations can exist.
The data of the Kepler mission and other telescopes show that in the known Universe of 2 x 10 22 stars, only 20% have planets located in the habitable zone. So we got rid of one uncertainty. But there are still two questions left. The last question seems particularly difficult (how long will alien civilization be able to survive), because scientists are guided only by human history. But we still exist.
At this stage, there are two options: pessimistic and optimistic. The line of pessimism indicates that earthlings are the only rational beings in the Universe. However, if the actual probability is greater than the line of pessimism, then alien civilizations have developed before us.
Based on SETI data and exoplanets summaries, the researchers determined the number of 1 in 10 billion trillions. This suggests that we have chances that there is another intelligent species with a long evolutionary history.
Yes, it seems that this is incredibly small. But imagine that a developed life had 1 chance per trillion to appear on the planet. That is what happened to humanity on Earth. But this suggests that in the entire cosmic history of the similar happened about 10 billion times!
The researchers emphasize that the revised interpretation of the Drake formula takes into account the entire history of the universe for 13.78 billion years. Therefore, exoplanet hunters are actively looking for signs of life, grabbing at any chance.