Is there life on other planets? We used to believe life could only exist on an earth-like, carbon based planet, with liquid water. This means that every star would have a narrow zone around it, a band, that would be able to produce a planet like ours. But as search our own world, and others in our solar system, this notion is being tested.
We have found a flourishing ecosystem at the bottom of ocean vent, where water temperatures exceed 300 degrees on top of the frozen Arctic and Antarctica, and in the boiling sulfur springs in places like Yellowstone National Monument. That life exists and thrives in such diverse zones would point to a rising likelihood of life elsewhere. We now know Mars had water on its surface. There is a good chance there is ice there. Ice has been found on the moon. Oceans exist under the ice of Europa, a moon of Jupiter and Titan a moon of Saturn. Much of the surface of Venus resembles those volcanic vents.
The greatest theme in science fiction is portraying intelligent aliens. Most of those portrayals aren't very good, and are pretty much humans in funny suits. But aside from that, I have always wondered myself how big the possibility of intelligent extraterrestrials. I definitely think there is life, I imagine it's all over our galaxy, probably abundant. But intelligent? I have to say I'm doubtful there are very many.
Why do I think that? I look at us. The dinosaurs were the dominant animal on this planet for 145 million years. They were wiped out 65 million years ago, not through any failure of their own, following their demise, mammals were able to flourish and they became the major species. Eventually homo sapiens evolved. Now some people have the idea that we are the end result of some grand natural plan, but it's not. We're just one experiment in the game of survival. And frankly, I'm no longer sure we're a viable one. We haven't even existed 1 million years, yet we are on the verge of destroying our nest and wiping out a large number of other forms of life on Earth. Does anyone seriously think the human race will survive a thousands years let alone make it 145 million?
In a nutshell we overpopulate, we devise ever new and more destructive weapons of mass destruction and we are so short sighted that even when we know we are going these things and we know what will happen to us if we continue on this path. But rather than concentrate on that, what are we doing? We're arguing violently over which God is the real God. We're stripping our world of all the things that make it alive – out fishing the oceans, destroying viable land that we need to feed us, we put in place an economic system that will fail if it doesn't grow continually, so every year more must be sold/produce/used. We all know this spiral can't go on, yet we make no attempt to fix the problem.
Are we addressing these things? No, we're concentrating on whether a man can marry another man, on whether a woman has the right to abort a fetus (a number of animals actually do this when their bodies know they can't care for it), we worship vapid celebrities and ignore the millions of starving members of our own species because they're not in our front yard.
I've come to the conclusion, that based on what I've seen, intelligence is not a good survival trait. And I think this will be reflected on other worlds. If they did occur, I hazard a guess they wiped themselves out just like we're doing, long before they reached the stage where they visit other worlds.