I just read an article from The Royal Astronomical Society. British. Nearly 200 years old. Well respected.
RAS says, “Astronomers anticipate 100 billion Earth-like planets.” That’s a lot.
It’s also a meaningless number.
Distant space travel is impractical. We’ll never visit a planet beyond our solar system.
I’m sorry. I don’t mean to be a wet blanket but, it’s true.
Humans can only live within a tight range of parameters. We need oxygen and moderate temperatures. We need food. We need to return to Earth! Carrying enough supplies to accomplish that is orders of magnitude beyond any capability we have now.
Time is a problem too. The nearest star, Proxima Centauri, is 4.24 light years away. Our farthest satellite, Voyager 1, is a little over 17 light hours away and it’s been in space since 1977!
To go light years would take centuries!
We know about a few extrasolar planets. Not as much as you think.
We know they’re there, orbiting some distant stars through mathematics. We don’t actually see them. We do see the gravitational effect they exert on their star. These space wobbles are covered nicely by the laws of physics.
But that’s all we’re really seeing–stars wobble. All we know about any planet beyond our solar system is implied from the actions of things we can see.
It’s cool that astronomers can make these projections. Alas, they have no practical application or purpose.