One of the most common unanswered questions scientists find themselves asking is 'Is there life on other planets?' Since the first famously documented UFO sighting in 1947, the idea of extra-terrestrial life has been debated almost non-stop. The subject has inspired many TV programs, such as The X-Files, and films (Mars Attacks, Independence Day, and the Men in Black films to name but a few). Scientists have come up with many new ideas and ways of trying to either prove or disprove the existence of life elsewhere. Mars is a very similar planet to earth in relation to size and atmosphere. Therefore it seemed like the most likely place to search for life. At the end of the 19 th century, an American named Percival Lowell built himself an observatory so that it was possible for him to study Mars in intimate detail when its orbit was closest to Earth.

At this time it had recently been suggested that the planet had a system of channels on the surface, present from the evaporation of flowing water. Looking through his telescope Lowell became convinced he could see a network of artificial canals. This led him to believe that there were intelligent beings on Mars who had built these canals. However, spacecraft have now visited Mars and found that there is no evidence of water at all. It is now thought that the lines he could see were the combination of Lowell's overactive imagination, and scratches on the lens of his telescope. We are now searching one of Jupiter's moons, Europa, as this seems to be the next likely place to hold life.

It is seen to be more likely, however, that we will find less intelligent life in one of two different ways: It may be possible for us to obtain material from another planet or moon or star from elsewhere in the Solar System. Spacecraft may be able to visit these bodies and, for example, use a robot to collect material for examination. This may be examined on site, or brought to Earth to be investigated in laboratory conditions. They could be tested for things such as evidence of fossilized organisms. Another, possibly slightly far-fetched hope is that we may find simple organisms like bacteria actually living on the desired planet. These ideas spanned from the discovery of rock on our planet that originated from Mars; knocked from the planet when a comet collided with it.

In 1996 a group of scientists created conflict by claiming that they had found evidence of fossilized bacteria in one of these rocks, but other scientists disputed this idea. The other possibility is that we can examine the atmosphere of other likely planets or moons. The planet Earth is largely made up of oxygen (20%) due to the presence of photosynthesis ing plants producing oxygen as a waste product. If an indication of oxygen appeared in a different planetary atmosphere, it would have a high chance of holding life forms on it.

To learn about different atmospheres it isn't mandatory to visit the planet. We can find this information by looking at the light spectrum it emits. People however think it would be more fascinating to discover intelligent life elsewhere. The Search for Extra-Terrestrial Intelligence project (SETI) has been running for several decades, but has not yet found any concrete evidence that intelligent beings truly exist outside of Earth.

Earth is constantly sending radiation into space. All broadcasting stations produce radio waves. These waves spread from a transmitter, and many of these end up in space, travelling away from us at the speed of light. It is very possible that, if there is intelligent life capable of producing these same signals, we will be able to pick them up. It is just as likely that they will deliberately send out signals that we will be able to receive, and will convince us of extra-terrestrial intelligence. The SETI project has been using radio telescopes since the 60's, but has had no positive results yet.

The SETI project began in 1959 when Philip Morrison and Guise ppe Coco nni publish in Nature magazine the first modern SETI article, 'Searching for Interstellar Communication,' which first illustrated the potential of using microwave radio for extraterrestrial communication. In 1960 Dr. Frank Drake conducted the first SETI search, Project Ozma. In 1961 the first SETI conference, Order of the Dolphin, is held at the National Radio Astronomy Observatory in Green Bank, WV. Dr. Drake introduces as its agenda what is now know as the Drake Equation, a controversial statistical method for estimating the number of advanced technological civilizations in the Milky Way Galaxy.

In 1982 NASA began SETI searches with The High Resolution Microwave Survey (HRMS). 1988 saw The Planetary Society organize an international meeting on SETI in Toronto, Canada. This led to a Robert Stephens establishing project TARGET (Telescope Antenna Researching Galactic Extraterrestrial Transmissions). In 1999 SETI@home, a new screen saver program that taps into the power of home computers, was launched. It has the potential of radically changing SETI program design in the future of extra-terrestrial searches. With all of this scientific research, it is no wonder that many people within the general public are intrigued by the subject of extra-terrestrials and UFO's.

Many UFOlogists (people who study UFO's in great detail) count the Kenneth Arnold's 1947 sightings as the 'original's ight ings, as they were the first to cause a major UFO Craze. However, there is evidence of alien activity as far back as the Old Testament. The prophet Ezekiel was documented in the Bible to be one of the first human beings to have a close encounter. The prophet writes of a whirlwind and a great cloud with fire enfolding itself. It then revealed itself as a 'wheel in the middle of a wheel'.

The craft shone like polished metal, and strange beings were observed inside. Thousands of years later, events like this are still occurring. There are countless numbers of UFO reports, including goings-on such as crafts flying at speeds of anything up to thousands of miles an hour, abduction, and UFO crashes. The most famous crash was 75 miles northwest of Roswell, New Mexico in July 1947. Sometime between July 3 rd and July 7 th something crashed in the desert near Roswell.

The first piece of information released claimed it was a 'crashed disc'. This was soon changed to being a weather balloon. Just this minuscule statement, and cross between objects, was enough to trigger the most famous UFO incident in history. Despite vehement denials from every Air Force and government spokesperson to date, nearly everyone involved in, and following the case, believes that the government is conspiring to hide the truth: an alien spacecraft crashed in 1947, and the Air Force is holding on to the wreckage. It is also believed that the extra-terrestrials involved in the Roswell crash were held by the government for top-secret autopsies and examination (see appendix 1).

There are many different beliefs and theories about how and why UFO's exist. Most people believe that UFO's simply don't exist, as there is no proof to back people up otherwise. The many photos taken of supposed spacecraft's have mainly been proved fake, or deemed too unclear to be taken seriously. However in the papers very recently (Friday 4 th October) a photo was printed that, although not all checks have been run on it, is very unlikely to be fraud (see appendix 2).

People who believe in UFO's generally see them as friendly creatures much like us, who wish to communicate for the same reasons as us-to see what is out there. Other people have other theories; some of them slightly 'out there'. One of these theories answers why extra-terrestrials, who have the extreme intelligence to create these crafts that can reach planets thousands of light-years away, would make the mistake of crashing to Earth. The idea is that a rare form of magnetite found in the sand in deserts attracts the metals used in the spacecrafts, and the force between them is so great that they are dragged to our planet. Another idea is that UFO's are not really from other planets at all, but created right here on Earth.

Supposedly Germans, Americans and Soviets started the 'Projekt Saucer' in Germany towards the end of World War II. During the war Germans sent ships to the Antarctic with equipment and plans for a massive underground structure. It is said that at the end of the war scientists and engineers who had been working on Projekt Saucer in Germany ended up in this underground structure, where even more advanced saucers were created. In a manner of thinking this is by far the scariest theory should it be proved correct, for it brings up more questions than it gives answers. What would people on Earth want to create spaceships for? Why keep it such a secret if everything is harmless? Maybe, if this theory is proved correct, it is better not to know the answers.

To conclude, there are no solid facts on the existence of extra-terrestrials. Whether or not they exist will, until definite proof is brought forward, be a topic of major debate. Personally I believe that there is something out there-although what it is I wouldn't hazard a guess.