Life exists on other planets. Out of the billions of solar systems, there has to be a chance that a least a couple planets have the ability to support life. Life may have developed on the planets like life developed here, but it may have developed differently also. Are they more intelligent than we are or are they single-celled organisms? Do they have broadcast capabilities, so they can contact us? It goes back to how life on Earth started. In the early days of Earth, the atmosphere was just carbon monoxide, but algae developed into plants which produced oxygen (Rather and Bowen 2). That brings us to the question of how the algae got here.

The answer to that question may lay right beneath us, at the bottom of the earth. There are scientists in Antarctica digging in the snow hoping to find some answers. Some of earth’s fossil records indicate that within a billion year period of it’s formation as a planet, as soon as heavy bombardment by asteroids ceased, primitive organisms such as bacteria and algae evolved and spread around the globe very quickly. Those organisms illustrated the totality of life here for the next two billion years or so. Therefore, if life exists on other planets, it might well be in this highly uncommunicative form.

Consequently it might be a while until it would finally evolve into a slightly intelligent form of life. As algae became more extensive, they began adding large amounts of oxygen to Earth’s atmosphere. The manufacturing of oxygen, fed by energy derived from sunlight, is fundamental to carbon-based life. Oxygen is a chemically reactive gas; without continued replenishment by algae and, later in Earth’s evolution, by plants, its concentration would fall. Consequently, the presence of large amounts of oxygen in a planet’s atmosphere is a good indicator that some form of carbon-based life may exist there.

But there is still a problem as to how the initial jump from non-alive to alive came about. We know a lot of details, and have a pretty good idea of how life got from algae to cat to man, but how we ended up with algae is the big question here. This mystery makes it hard for us to figure out how life would arise on other planets. Life is not all that mysterious, it is a property of a collection of extremely complex molecules (Britt 1). In order to help people figure out what planets out there could support life and may have life on them, we have to look at what life needs to survive.

If other planets had carbon-based life they would likely have the same or close to the same chemistry that earth has. Water is an excellent solvent for life’s biological reactions and serves as a source of needed hydrogen. Carbon is a particularly suitable building block of life. Carbon is abundant ‘in this universe, and no other known element can form the myriad of complex but stable molecules necessary for life as we know it. It is believed that if a planet looks like Earth and has liquid water and oxygen, then this would present strong evidence for its having life.

There could be some other non-biological source on a lifeless planet. Life could also develop from some other type of chemistry that does not generate oxygen. We should still be able to detect all stirring from chemical residues. There is a theory that maybe life came from outer space, or the comets and meteorites in it. Like giant interstellar sperm, comets might transport the seeds of life from collapsed space clouds to fledgling and otherwise barren planets, depositing their life-giving substances in a colossal impact (Britt 1).

A new computer shows that at least one building block of DNA could develop in space when giant clouds of molecular matter collapse under their own gravity, squeezing and forcing chemical reactions. If the controversial theory gains support, it would be a shot in the arm for an idea more than 20 years old: that life on Earth originated in space (Britt 1). This theory could explain how life got started on our planet so soon after this planet was formed. It definitely proposes that life is not as rare or as tough to jump-start as we might think.

This confirms the idea that life isn’t all that rare. The list of planets beyond our solar system is growing by leaps and bounds, and scientists are developing new methods to expand their reach toward these other worlds. The tally of extra solar planets has raised to more than 50. All of these planets were detected indirectly, in most cases using a radial velocity technique that analyzes subtle variations in the light coming from distant stars (Boyle 1). Planet-hunters say such differences are generated as they orbit the stars.

The most notable detection relates to a planet circling the star Epsilon Eridani, just 10. 5 light years or about 63 trillion miles away (Boyle 1). That would make it the closest world ever found beyond our solar system. Researchers analyzed nearly 20 years’ worth of observations from four different telescopes to conclude that the faint variations in Epsilon Eridani’s spectrum were caused by a circling planet (Boyle 1). Some scientists have been looking at dust trails around stars and have concluded that dust trails bare the signatures of unseen planets.

But all of the planets found in this manner are thought to have orbits much wider than Pluto’s track around our sun, meaning that they will most likely not be inhabitable by life. We’re now at a stage where we are finding planets faster than we can investigate them and write up the results (Boyle 4). All of these results hint that our celestial neighborhood could be a fertile field for planets like Earth. None of the methods used so far are fine enough to detect Earth-like planets directly.

However, in the next 10 years, scientists hope to develop space-based instruments capable of spotting such worlds around relatively nearby stars (Boyle 4). Possibly even analyze their atmospheres for signs of life. In order to find some of these planets people need to have a lot more powerful telescopes than they now have. To detect them we would have to have a telescope 100 meters in diameter in space but we cannot launch something like that (Dalton and Lambie 2). Many scientists believe that planets similar in size, distance from the sun, and have oceans of water like Earth are likely to sustain life.

If each star has planets spanning a range of orbital distances, as occurs in our solar system, then one of those planets is likely to orbit at the right distance to sustain liquid water, even if the star shines more or less brightly than the sun. Temperature means little if a planet’s gravitational pull cannot hold on to oceans and an atmosphere. If distance from a star were the only factor to consider, Earth’s moon would have liquid water (Angel and Wolff 3). But gravity depends on the size and density of the body.

Because the moon is smaller and less dense than Earth, its gravitational pull is much weaker. Any water or layers of atmosphere that might develop on or around such a body would quickly be lost to space. Three key compounds that we would expect to find on inhabited planets ozone, carbon dioxide, and water leave strong imprints in a planet’s infrared spectrum. To see a planet’s infrared spectrum, the telescope would have to be placed in space. There would be no way that a telescope on Earth would be able to see the planets infrared spectrum.

Polls show that 54% of Americans are convinced that there are aliens out there, to say nothing of the significant fraction (30%) who suspect we’ve already been visited by them (Golden 1). If there is other life out there, what are the chances of finding it in our lifetime, or even our children’s lifetime. Conditions have to be just perfect to develop life. Under the right circumstances life can arise pretty easily. That is if it does reach a level advanced enough to broadcast its presence, it won’t destroy itself in a nuclear war or an environmental meltdown before firing off Earth-bound messages.

Could this be a prophecy of what will become of this planet? Hunting for extraterrestrial’s requires a lot of faith (Golden 1). Even scientists shy of success don’t want to be malcontents. They agree on the importance of continuing the quest, not just for the microbes on Mars or Europa but also for those faint signals from some remote world. The question still stands. Does life exist on other planets? Are they intelligent or are they microbes? Will we ever really know?

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 19th 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 fossilised 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 fossilised 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 photosynthesising 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 Guiseppe Coconni 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’ sightings, 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 Ezekial 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 3rd and July 7th 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 miniscule 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 4th 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.