Anyone that says "there are no space aliens" (to mean sentient life on another planet) is just asinine.
Earth is one planet among several in our solar system.
Our solar system is one among billions in our galaxy.
Our galaxy is one among hundreds of billions in the known universe.
The furthest that mankind has traveled is to our moon.
The furthest that any of our probes have traveled is just beyond the edge of our solar system. Voyager I is now in interstellar space. It is still in our galaxy.
The closest star with a known planet is only 4.2 light years away. That would be Alpha Centauri. Unfortunately our space shuttles don't have warp speed, so the best they can muster is an agonizingly slow 17,500 mph. At that speed it would take around 165,000 years to get there.
Light travels at 671,000,000 mph and some stars/galaxies are so far away that light has been traveling for billions of years and is just now visible to us. Looking at light from stars is to look at ancient history, not what is currently going on in space.
And some people think that we can make definitive answers about what all is out there?
We are mere infants when it comes to exploring the cosmos.
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