It may have been the most unusual question to come up at a Presidential debate. When moderator Tim Russert asked Democratic candidate Rep. Dennis J. Kucinich if he'd ever seen a UFO, the Ohio Congressman didn't hesitate. "I did," he replied. While this led to much amusement in the media, it also prompts a more serious look at the phenomenon of Unidentified Flying Objects.
Humans have long asked: Are we alone? Has our planet ever been visited by others? Among those committed to the search for evidence of life beyond Earth are the scientists at the SETI (Search for Extraterrestrial Intelligence) Institute. Thanks to a huge donation from Paul Allen, the co-founder of Microsoft, SETI-in partnership with the University of California at Berkeley-is building a network of radio telescopes near Hat Creek in Northern California. Known as the Allen Telescope Array, its purpose is to pick up signals from space.
Currently, there are 42 telescopes in place. In 2010, when the Allen array is completed, 350 telescopes will scan the stars as far as 1000 light-years away. (They will not be looking for visiting craft, just radio signals.) These individual telescopes will be searching different regions of the sky, but they can be combined into one giant telescope if needed to confirm someone's call from the darkness of space.
Sightings of UFOs have occurred since biblical times. Renaissance artwork includes visions of strange flying objects in the sky. Many modern-day sightings are on record, and some remain mysteries to this day.
Some sightings are not easily dismissed. Years ago, the late Clyde Tombaugh, the man who discovered Pluto, observed green fireballs in the sky. Unlike the ordinary greenish fireballs that occasionally brighten the night, these appeared as a group and seemed to speed up during their flight through the sky.
But the more he thought about it, the more skeptical Tombaugh became about his sighting. "Even if they were visiting from a planet circling the nearest star, Alpha Centauri," he once told me, "an almost infinite amount of fuel, as we understand it, would be required to accelerate them from their home to ours. There must be another explanation."
Jack "Triple" Nickel, a retired Air Force fighter pilot, also is a respected astronomer. Early in his career, in the fall of 1973, as he flew at night between clouds over Oklahoma and Texas, a bright light suddenly appeared in front of him. "It was either close by and dim or far away and bright," he recalls. "It lasted about 20 minutes before vanishing." Nickel can't rule out the possibility that the light was the bright star Sirius shining through a break in the clouds, but the sighting was never explained.
Still, most of the strange sights in the night sky are easy to explain - whether it's Venus, the northern lights or even an artificial satellite passing for a UFO. For example, pilot Tom Wideman was flying over California late one night in 1986 when he witnessed "a blazing fireball that crossed our path from right to left, trailing flaming debris before it went out of sight." The next day, Wideman learned that a Russian rocket booster had burned up on re-entry over the Mojave Desert. "It had crossed 20 miles in front of our flight path, close enough to be spectacular." Many scientists, myself included, believe we are probably not alone in our galaxy but that most likely no one has visited us yet. Even if a UFO landed in my backyard, I'd want to have a look inside and meet the occupants before I'd be convinced.
Recently, just before dawn, 11 faint lights appeared in my telescope's field of view. They climbed the sky, slowed, stopped, then started back toward the horizon. I thought about it for a while. Then it hit me: About 300 miles from my Arizona home is White Sands Missile Range, a facility that frequently launches rockets. I must have witnessed a missile launch.
If you hear a UFO story, be skeptical. Ask questions. If someone describes an object that hovers in the sky, motionless, then tears off at twice the speed of sound, ask how it could suddenly move that fast, breaking Newton's law of motion. It has to accelerate to that speed, and the faster it speeds up, the more force is needed. In the meantime, keep watching. Seeing unusual things is just one reason to look up at the night sky, eagerly and passionately, and wonder.
