We can’t see them! It doesn’t mean they do not exist. The below calculation may stimulate your curiosity
Our Milky Way is predicted to contains an amount of stars from 100 billion to 400 billion. Statistically, every star would have at least one planet. As for the maximum number of planets for each star?
Don’t ask me! I don’t know.
The most definitive conclusion has been reached: our galaxy contains a minimum of 100 billion planets and most of them are small planets like ours.
And the universe has only our Milky Way?
The answer would be yes if you were from the beginning of the 20th century. This was before Edwin Hubble recognized the Milky Way wasn’t the only galaxy in this universe by using the standard candle law to determine the location of the Andromeda galaxy.
Exactly 87 years 2 months 23 days 11 hours 9 minutes 32 seconds after Hubble’s identification, (the time I was writing this article), there are 500 billion visible galaxies in this universe! Furthermore, how many universes are there?
Again, don’t ask me! I don’t know.
Therefore the amount of planets (x) in this universe would be at least:
x = 100 billion x 500 billion = 5 x 10(^22) planets (not including planets of some bespent galaxies)
y = 11000 planets (the amount of planets have been found by humans)
The difference between those 2 values of x and y shows us that we did find “a lot of planets” in this universe. On the other hand, of the 5.000.000.000 billion planets in this universe, one of them has been found by us. What a big achievement, isn’t it?
This means that the chances of life and habitable planets in this universe is overwhelmingly high. So high that it’s impossible to deny that it’s out there. The only question is how much of that is capable of supporting life and of that life, how much is civilized.
“Don’t say zero!”
Of course, how much of this life is smart enough to build computers, communication dishes. But the we are actually not really as gentle as some science fiction story said. If the extraterrestrial-life had existed on Mars, would we have controlled them? Absolutely!
“No? This is a real article, We’re not talking about science fiction any longer!”
They would have done that because we are nervous if they are smarter and stronger than us, they would do the same thing to us. Not long after the Wow signal, we launched 2 spacecrafts Voyage 1 and 2 which contained “some significant information”.
“We are friendly, we sent to the aliens our location, they will come … soon for … a birthday party”
Trinh Manh Do