Are we Alone In The Universe?

NASA Armageddon? - an asteroid impact on Earth

Some people use the so-called 'insurance policy argument' to advocate a manned space programme. There is an ever-present risk (though fortunately a small one) that a comet or asteroid will hit the Earth. The craters on the Moon's surface are records of these impacts. An impact on Earth - leaving a huge undersea crater near Chicxulub in the Gulf of Mexico, probably sealed the fate of the dinosaurs 65 million years ago.

There is about one chance in 10000 that, within the next 50 years, the Earth will be hit by an asteroid large enough to cause world-wide devastation -- ocean waves hundreds of feet high, tremendous earthquakes, and changes in global weather. This chance is low - but no lower than the risk (for the average person) of being killed in an air crash. Indeed, it's higher than any other natural hazards that most Europeans or North Americans are exposed to.

The ever-present risk from nature has been augmented since humankind entered the nuclear and biotechnological age. Humanity will remain vulnerable to these (probably increasing) hazards so long as it is confined here on Earth. But once self-sustaining communities exist away from the Earth -- on the Moon, on Mars, or freely floating in space -- our species would be invulnerable to any global disaster, and whatever potential it has for the 5-billion-year future could not be snuffed out.

Whether on not humans spread beyond the Earth during the next millennium, we'll still want to know whether we are alone. It would in some ways be disappointing if searches for alien intelligence were doomed to fail. On the other hand, it would boost our 'cosmic' self-esteem. If our tiny Earth were a unique abode of intelligence, we could view it in a less humble cosmic perspective than it would merit if the Galaxy already teemed with complex life. We'd have even stronger motives to cherish this 'pale blue dot' in the cosmos, and not foreclose life's future -- a future that could be even longer than the time span over which simple life has evolved into humans. That is why we should expand our cosmic vision in the new millennium.

For more information:

Could aliens be visiting Earth. Perhaps the evidence is hidden in government documents. See here about downloading the TV documentary 'British UFO Files'
http://www.firstscience.com/home/firstscience.tv/british-ufo-files_3.html

Video: Alien Contact [Firstscience presents]
Today, most scientists are convinced that we are not alone. But what life exists in our own back yard – our Solar System?