If just one in ten stars have a planet in their habitable zone, and one in ten of those planets are earth type (made of rock, possessing an atmosphere, and more or less the same size), that’s still 500 billion billion planets with potential for harbouring life as we know it. Not to mention that we’ve no idea, really, how life considerably different from anything we know might arise and evolve under considerably different conditions on considerably different planets.
I’m pretty sure we’re not alone, though our nearest neighbours may be somewhat farther than just a quick stroll down a country road.
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This computer-generated video contains only 400 000 galaxies, and still looks amazing.
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And that’s just ten square degrees. The full sphere of the sky is 41,253 square degrees. If evenly distributed, this amounts to 41,253,000 galaxies, which in itself is a pretty large number to wrap one’s mind around, though it is easily dwarfed by the 170 billion ones already mentioned. Future telescopes will be sharper and more light-sensitive yet, likely to reveal even more galaxies and in greater detail.
Though if you look at the night sky, even if you’re in a place with little or no light pollution from nearby cities or residential areas, with the possible exception of the Andromeda Galaxy which you will only catch sight of if conditions are right and you know where to look, every point or patch of light that you see are only relatively nearby stars and nebulae, and no more than a handful thousand of those at best. In other words, you see only a fraction of a fraction of a fraction of what’s in our own galaxy, let alone any other.
The most awesomely amazing things are out there, far out, in the dark patches between the stars that you can see, invisible to our eyes, and visible to our technological viewing aids only through special effort. But they are out there. And I’m pretty sure that right now, on at least one of the planets around one of the stars in one of those countless galaxies, someone is looking up at their night sky in our direction, wondering if there’s anyone out there.