If our government has actually retrieved crashed UFOs and recovered bodies therein, why is there zero proof of this? Surely hundreds, probably thousands of people have been involved in those recoveries and research, and yet no one has actually spoken up. Or produced photos, or anything from those supposed crashed vehicles.

Probably because there are no aliens, no craft from else where, nothing.

People don't understand that vast distances between stars just in our own galaxy, and that the speed of light is an absolute limit on how fast anything can travel. Don't just invoke "vastly more advanced science" because no matter how advanced, the speed of light still rules.

Oh, and you need to be aware of just how much truly dangerous radiation is out there. It will kill you. The faster you travel, the more radiation you absorb in a shorter time. So actually surviving an interstellar journey is highly unlikely. Don't just take my word for it. Read "How to Die in Space" by Paul M. Sutter.

And all the looking at stars, all of the discovered exo-planets, there is still, so far at least, no hint of any kind of truly earth-like planet that might possibly have life as we know it. My Son The Astronomer is doing exo-planet research, and he tells me that the vast majority of planets they've found so far are either not inside the Goldilocks Zone, or if they are, the zone is so close to the star that they are rotating very, very, very fast, which probably isn't real conducive to life evolving.

It's also important, probably crucial, that we have our Moon. It's what gives us our tides, and that may be the very most important thing for life to evolve.

Also, while the earliest life seemed to happen almost as soon as the planet cooled, it took a whole lot longer for the first life to become multi-cellular, and eventually the complex organisms we know today. Oh, and the major extinction events matter. They cleared things so that new, different kinds of plants and animals could evolve.

People will blithely say that there are so many stars and planets out there, that surely many of them have life, and have evolved intelligent life. A few things to be aware of. Something like 70% of the stars in our galaxy are red dwarfs. If a planet around one of them develops life, it will undoubtedly be a lot different from what we know. It is also possible that intelligent life might evolve on a water planet, and they never actually look up at the night sky and see the stars. They won't be going anywhere.

There's also time. We humans have been around for perhaps 300,000 years, but only in the last several thousand developed what we call civilization, and technological civilization much more recently. Overlooking the fact that we are well on our way to making this planet uninhabitable, just how long might our species survive? Keep in mind that evolution, including human evolution is ongoing, and most species last around a million years before going out of existence.

Oh, and the last plane crash with fatalities in this country was, do you want to guess? 2009.