I think there are aliens out there. They're just so far away, we'll never see them.
Although I do believe in space aliens, I don't believe in faster-than-light space travel.
There's probably a race of aliens living on a planet a thousand light years from here. They sent probes out to other star systems the same way we send probes to other planets. They probably sent a probe to every star within a thousand light years from their planet. It went at 5 percent of the speed of light and took 20,000 years to get here. It flies around Earth a few times. Takes some pictures. Sends them back, then flies off to the next planet. We see it as a UFO and wonder about it.
Some people think an alien space ship crashed here and scientists are secretly studying its technology. Do you actually believe those stories? If that were true, we would know it because our technology would be doubling every two years.