I believe that in this whole big universe, the fact that eart can devekop as much as it has means that somewhere else another planet full of other life forms can do the same? I think for every star there is an alien planet. What do you all think?
Most Helpful Guy
Great question. I have always been very interested and fascinated by astronomy, since I was a very small boy. My dad sometimes went an a quiet hill outside of town where there wasn't a lot of light pollution to look at the night sky.
While we can't know for sure yet, it seems mathematically almost certain that other life forms exist in the universe. However, your statement that every star has its planet with life is not correct (unfortunately). We know already quite a few (in the thousands) solar systems and for many of them we can be practically certain that life does not exist there. How do astronomers know this? In order to sustain life, a planet has to be in the so-called Goldilock-zone. It's a zone in a particular distance from the planet's sun where the conditions are juuuust right. It's not too hot, it's not too cold. Water should exist and it should be liquid. But then of course there are other conditions such as the planet being a rock planet just like earth (which should be the case if liquid water exists), it should have an atmosphere (very important!) it shouldn't be too big or too small, it shouldn't have toxic gases in its atmosphere that harm DNA etc.
So, you might think this is very difficult to find because there are so many conditions. But the number of planets in the universe is so astronomically high (no pun intended), that the chances of extraterrestrial life existing are actually very good.
It has been calculated that there are more planets in the universe than grains of sand on every single sand beach on earth (just to give you an impression of the kind of numbers we're talking about.
However, don't get too excited to soon. There are two bumpers.
First of all, chances of life existing are very good but chances of intelligent life existing are actually not very good (according to astronomers). When astronomers or astrobiologists talk about Aliens, they also include things like bacteria or algae or fungus. Now, for scientists they might already be a sensation to find but for most normal people not so much because we can't actually talk to them.
Secondly, because the universe is so huge, it is almost certain that we will never ever meet these aliens. Even if we developed a space ship that can fly with the speed of light (which is scientifically and technically impossible), it'd take us 4,5 years just to get to our very closest neighbor star. Some scientists even say we must not meet aliens because it would end up in a catastrophe.0