Some people feel we should be doing everything possible to explore space. But others think it is a needless waste of taxpayer dollars when there are so many problems here on earth. Of course, space exploration is expensive. But is it worth the cost? In a time of huge public debt and shrinking government budgets, money for space exploration is bound to be controversial. However, several recent discoveries have increased public interest in space exploration to the highest level since the time of the moon landings.
Assuming space exploration continues, it is quite possible that human explorers will encounter life on other planets. Just as on our own world, most of this life would undoubtedly be of "lower" kinds, that is, not intelligent. It is also possible that we will find, not living specimens, but fossils. This is now considered a strong possibility on Mars.
Some people think that discovering life on other planets will be one of the most important discoveries in all of human history, with *profound implications* for many aspects of our lives.
Today, most space scientists do not expect to find intelligent life on any other planet in our solar system. However, some researchers think we might be surprised to find that "cosmic tourists" or explorers from far away may have stopped off at Mars, for example, and left evidence of their visits. After all, we humans have already left *evidence of our visits on several other worlds.*
Mars has always been a popular candidate for life. In the early part of this century, the famous astronomer Percival Lowell said he could see "canals" on Mars through his telescope, and he believed these canals were made by intelligent beings. This idea f ired the public imagination. Today it is clear that Lowell was wrong about the "canals." But there is now some new evidence of possible life on Mars, and several unmanned spacecraft will arrive there this year to learn more.
One kind of evidence for life on Mars came from a meteorite. Do you know where it was found? Do you know what kind of evidence it contained? *Check here to find out.*
Another kind of evidence for possible life on Mars came from photographs of a region called Cydonia taken by the Viking spacecraft orbiting Mars in 1976. These photos are VERY controversial, and many scientists have tried to ignore them. But recently, NAS A announced that they would try to get better photos of Cydonia, using the Mars Global Surveyor spacecraft that will arrive there in September 1997. NASA has always said the Viking photos of Cydonia just show various rock formations that cast interesting shadows. Other researchers say the Cydonia landforms are artificial structures. Everyone hopes the new photos will settle the question. *Find out more about Cydonia here.*
As far as we know, almost all forms of life need water. It turns out that water is more common in our solar system than we once thought. In fact, water was even found on the Moon recently, although we don't think there is any life there. But there is a lo t of water on Mars. And there is also a lot of water on some of the moons of Jupiter. One of those moons, Europa, might actually have oceans of liquid water under a permanent outer layer of ice. Some scientists think Europa is a very good candidate for so me kind of life. But Europa is VERY far away from the sun. How can it be warm enough to have liquid water? *Find out here.*
For a long time, astronomers have believed that other stars, like our sun, probably have planets. But it wasn't until 1995 that they got really good evidence of a planet around another star. After that, they began to find good evidence for planets around lots of stars. Now it seems that planets might actually be quite common. This is a major new idea in astronomy, and of course it increases the possibility that there might be life "out there."
If we really want to learn about planets around other stars, if would probably be good to go there, just as we're going to nearby planets today. We've all seen movies and television shows about interstellar space travel, such as Star Trek. But are these s tories pure imagination? Will we ever be able to travel that far? Some scientists think such travel is very unlikely. But a new breed of physicists and engineers say it can be done.
There are lots of unanswered questions: How fast can a spacecraft go? What is the best kind of power source? How expensive will it be -- and can we afford it? How dangerous will it be? Can humans adapt to very long periods in space? Could a spacecraft con tinue to communicate with the earth if it got very far (light years) away?
One of the really big questions is: Can a spacecraft go faster than the speed of light? Any fan of Star Trek knows that "Warp Drive" allows faster-than-light travel. Something like this would probably be necessary if humans are ever going to visit distant stars. And, conversely, visitors from "out there" would probably need it too, or they couldn't reach the earth. *Is "warp drive" possible? Find out here.*
Of course, if we humans realize that "warp drive" is possible, then it's also possible that someone "out there" is already doing it. And then... maybe those stories about "flying saucers" aren't so crazy after all!
