Eleven witnesses, including cops and firefighters, either see the crash or rush to the scene within 15 minutes to watch the flames from the molten metal -- mostly carbon steel -- that covers the ground.

It happened on Dec. 17, 1977. The “big round thing” that local resident Criss Moore saw hovering in the air 25 years ago has never been explained.

No one knows if aliens are really blowing up their starships over Council Bluffs. But if extraterrestrial life forms are visiting from time to time, somewhere some sentient beings must have figured out a way to transit interstellar space. Discussions about unidentified flying objects march hand in hand with the feasibility of interstellar space travel.

Earlier this month, George Washington University and the Sci-Fi Channel sponsored a symposium at the university where serious people took up these two topics. Scientists agreed that we won't be doing star trips anytime soon, but “soon” may not mean much in the context of the cosmos.

“The universe is 14 billion years old,” said symposium panelist Michio Kaku, a theoretical physicist from City University of New York. “Human civilization only began 5,000 years ago.”

So give science a chance.

The trick, of course, is to be able to travel faster than the speed of light -- 186,000 miles per second -- which is as fast as anything travels in the world as we understand it, but not nearly fast enough to commute to stars. Our nearest stellar neighbor, Proxima Centauri, is 4.2 light years away.

There are glimmers about how this problem might be overcome. They involve bending space-time in such a way that one could scoot Enterprise-like through the cosmos.

One way is through “warp speed,” implying that we can move faster than light through space-time by distorting space-time itself. The National Aeronautics and Space Administration (NASA) likens warp drive to a moving sidewalk: A person walks at one speed but travels much faster because the sidewalk moves as well.

Another way to distort space-time is by harnessing an enormous amount of energy -- like that of an entire star -- to create a pathway, or “wormhole,” connecting two points that used to be separated.