Remember that the four most common elements in a human body matches four of the five most common elements in the universe (the fifth is helium, which is chemically inert and therefore does not participate in the chemistry of the human body). The sun is a completely average G5V star, and the Earth is just a rocky planet.
It’s not only possible, but it’s highly probable that the universe is full of life. The building blocks of life are spread throughout the cosmos.
Phosphine was found in the atmosphere of Venus, a gas that here on Earth is of organic origin;
On Mars, numerous pieces of evidence have been collected that indicate the habitability of the planet in the distant past or even in the present. And in the 1970s, NASA received virtually undeniable evidence , which was unknowingly destroyed;
Ceres, a dwarf planet in the asteroid belt between Mars and Jupiter, has a subsurface ocean that is abundant in organic matter. Probably there is life there;
Some satellites of the gas giants have subsurface oceans, in which life could also once have originated. On Enceladus, the satellite of Saturn, methane was discovered at all , which is an indirect, but very weighty argument in favor of the presence of life;
Titan, a satellite of Saturn, does have a dense atmosphere and reservoirs (rivers, lakes, seas) of liquid hydrocarbons. In addition, the molecule cyclopropenylidene, which underlies DNA and RNA, has been found in its atmosphere. Probably, there is life there, which has practically nothing to do with life on Earth.
A universe is a machine. A machine that created itself and then perfected itself over 13.8 billion years to evolve into an increasingly stable state. If the Universe makes any mistakes, then it seeks to eliminate them as quickly as possible.
Primary life, which originated on Earth about four billion years ago, went through an incredibly complex and long way to produce all this diversity of flora and fauna that we observe today.
Of course, some species disappeared, but more adapted, stronger or even … reasonable ones came to replace them. To call life a mistake in the universe is simply impossible, since in one form or another it has existed for too long.
Yes, scientists have not yet found extraterrestrial life, but it seems that humanity has come close to this event. And this is very important, because if one day we find some insects outside the Earth, then the spirit of explorers and discoverers will wake up in us; we want to find something bigger, like us, because anthropocentrism is the basis of our existence.
As far as intelligent life, there is absolutely no reason to think that our galaxy wouldn’t have hundreds of civilizations, some space-faring and others not.
To think otherwise would be very inward thinking on our part. And let’s face it, the universe could have hundreds of billions of galaxies.
It is sure that meteoric impacts on earth have sent billions and trillions of pieces of rock with bacteria into space.
It is sure that those rocks have landed on millions of planets in the habitable zone in the Milky Way. Due to the very fast revolution of solar systems around the Milky Way of 140 miles per second, ejected rocks only have to stand still to hit other solar systems quickly.
It is sure that the same meteoric impacts have happened on all of those millions of planets that were seeded by earth and that those impacts have seeded billions of planets in the habitable zone in the Milky Way, probably all 40 billion of them.
Did the bacteria on earth come from meteorites from other planets that rained on early earth? This is much, much, much more likely than bacteria forming on earth first before receiving any outside bacteria.
All in all, it’s 100% certain that there is bacteria from earth on many other planets in the Milky Way.
It’s also 100% certain that those evolved into more complex forms. Did they evolve into intelligent life? We can’t say that 100% yet, but that’s also more likely than not.
Why haven’t we heard of them? That requires another answer. However, in short, it’s quite likely that intelligent species went into cyberspace around 300 years after their industrialization.
For example, it’s expected that we can upload our brains into the cloud within a few decades. This would move our civilization to a higher plane, that doesn’t care about this plane of existence.
It’s expected that A.I. will surpass the intelligence of all human brains within a few decades. That would result in the same scenario as #1.
All in all, it’s sure that there is earth bacteria on millions of other planets in the habitable zone.
Have they developed into intelligent life? Quite likely. Do they care about establishing contact with us. Probably not.