Who Built the Moon? (13 page)

By far the majority of experts now accept that if advanced life of any sort does exist in places other than the Earth, we will almost certainly have to look deep into interstellar space to find it. Our solar system is only one of many that undoubtedly exist, even in our own corner of space. Astronomers have identified suns that have planets orbiting them and it is estimated there are a thousand million stars in our own galaxy, any one of which could possess a planetary system where life might have evolved and flourished. Beyond our galaxy there are countless others, so it may be wrong to think that only our tiny little blue planet, amidst such a proliferation of planet-bearing suns, has produced a thinking species such as our own.

But as far as we know right now, we are alone.

Once the sheer size of space was ascertained it also became apparent that even if there are hundreds or thousands of intelligent species out there, the chances of us actually encountering them in any way is quite small. Distance is a problem but it isn’t the only one. One of the greatest stumbling blocks could be time itself. In order for us to communicate with another advanced species, it would have to have reached at least our level of sophistication either at the same time as us or shortly before. Although humanity has created at least a couple of probes that are presently leaving the environs of our own solar system, it will be decades, or maybe centuries, before we embark on interstellar space travel to any significant extent. Even if we do, the answers we are looking for, in terms of finding other intelligent beings, are likely to be protracted.

The thought of any spacecraft travelling faster than the speed of light remains in the realms of science fiction. If, as Einstein proposed, light speed is as fast as anything can ever travel, it would take many years merely to reach the nearest star. To go beyond our own galaxy, the Milky Way, would seem impossible because the next nearest place we could visit is the Sagittarius Dwarf galaxy which has ‘only’ a few million stars and is a staggering 80,000 light years away. The next nearest galaxy is the Large Magellanic Cloud and that is 170,000 light years distant.

Setting out to actually meet our intergalactic or extragalactic cousins seems to be a hopeless idea, even if we knew where they were located. So does this mean we can never say hello to any of them? Not necessarily. If we cannot greet them face-to-face, it might be possible to listen to them.

Much of the energy so created streams out into space as electromagnetic radiation. There are many wavelengths of this radiation, some of which are familiar to us in our daily lives. The full panoply of this radiation is known as the ‘electromagnetic spectrum’. The shortest of the wavelengths are those we call ‘gamma waves’. At the other end of the electromagnetic spectrum are extremely long radio waves, which we harness every day. Visible light is also a component of the electromagnetic spectrum, as are the microwaves used daily in many cookers.

In fact we are getting radio messages from all parts of the cosmos all the time. These are emitted by suns and other much stranger bodies within our own galaxy and beyond it, as a result of the physical processes taking place within them. Electromagnetic radiation travels across the near vacuum of space at the speed of light. Once it was realized that we could listen in on the processes taking place in our stellar backyard and beyond, radio astronomy was born.

In 1931 an American engineer by the name of Karl Jansky, who was working for the Bell Telephone Laboratories, was conducting experiments into interference that was taking place across certain radio wavelengths. He built a succession of aerials and managed to isolate three distinct sources of radio interference or static. Firstly he could detect local thunderstorms; and secondly, storms taking place at a greater distance. However, there was a third source of interference that was steady and always present which he couldn’t, at first, identify. By moving his aerials, Jansky was eventually able to isolate the source of this third form of radio interference. To his own and many other people’s great surprise it was coming from within the Milky Way and in fact it originated at the very centre of our own galaxy.

Like many controversial discoveries Jansky’s were ignored for some years. But not everyone was sceptical. Reading about Jansky’s observations, in 1937 another radio engineer, Grote Reber, built his own aerial, though this one would have been more familiar to a modern radio astronomer because it was a dish. Reber also picked up the strange ‘messages’ from space.

Interest in the signals from space gradually increased. In 1942 a British Army officer, J S Hay, made the first observations of radio emissions from our own Sun, whilst working on ways to jam German radio signals. Once the Second World War was over, radio astronomy really took off and within a few years discrete signals from all parts of space were being received. Ultimately a background radio source was recognized that could not be isolated to a particular point in space and it was finally realized, in the 1960s, that this was the signal left by the Big Bang – the very birth of the Universe itself.

Of course, all the signals that were being received were perfectly natural in origin. But towards the end of the 1950s it began to occur to a number of those involved in radio astronomy that if any species out there in space was already more advanced than we were, it might well make use of radio waves in order to let us know it existed. Most radio signals received from space can be readily identified and even those that proved to be a puzzle at first have been shown to have a natural origin. But if an advanced species actively wanted to send a message, it would not be difficult for it to use a type of radio signal that could not be confused with that created by any natural phenomena – for example, one containing an obvious mathematical formula.

In 1961, when the ‘race for space’ had fired the imagination of a generation, a new organization came into existence. It was called SETI – ‘the Search for ExtraTerrestrial Intelligence’. SETI was primarily the brainchild of an enthusiastic young electrical engineer turned radio astronomer by the name of Frank Drake, a 31-year-old engineer who had become interested in radio astronomy whilst at Harvard Graduate School.

Drake was fascinated by the prospect of radio astronomy being used to identify other intelligent species in the cosmos and thought that we should be actively listening in for any message that might be transmitted from deep space. Together with another interested scientist, J Peter Pearman, an officer on the Space Board of the National Academy of Sciences, Drake arranged the first SETI conference.

Anxious to show the world just how likely extraterrestrial life surely was, Drake came up with what is now known as the ‘Drake Equation’. This reached the conclusion that there must be many thousands of intergalactic civilizations capable of creating and sending radio messages across space.

The idea of SETI was immediately popular with the public and for a while NASA had some involvement. During the 1960s and ’70s, NASA’s contribution was fairly low-key, but in 1992 nasa initiated a much more formal SETI programme. Unfortunately, less than a year later, the United States Congress cancelled the funding and NASA, reluctantly, pulled out of the SETI research programme. This certainly wasn’t the end of the story because a proportion of the intended NASA research was taken over by the non-profit-making SETI Institute and by an associated body, the SETI League.

SETI has now enlisted the help and support of people from around the globe. Many computer users are regularly sent packages of information received by SETI, in order that it can be analyzed during computer down time. Millions of individuals are involved in what is known as the SETI@home project at the present time.

Exactly where in the electromagnetic spectrum we should be listening for deliberately created messages from the stars was decided in 1959. Phillip Morrison and Giuseppe Cocconi, two young physicists at Cornell University in the United States had co-operated to submit an article to the prestigious science journal,
Nature
, which appeared in September 1959. It was entitled ‘Searching for Interstellar Communications’. When trying to ascertain which part of the electromagnetic spectrum to monitor for alien signals, Morrison and Cocconi ultimately opted for a frequency of 1420MHz. Not only does this frequency fall in a very ‘quiet’ part of the available spectrum, it also represents the emission frequency of the most common element in the Universe, which is hydrogen. Morrison and Cocconi believed that any intelligent species would realize these two facts and so would therefore be most likely to transmit a greeting at or around this frequency.

Some promising messages have been received across the last three decades but, in the end, all of them turned out to be natural phenomena. Space can supply some surprisingly ‘ordered’ signals. Rapidly spinning objects in space known as ‘pulsars’ are a good case in question, so SETI experts are extremely careful and also deeply sceptical when any apparent ‘letter from the stars’ is announced.

One of the greatest problems for SETI, or indeed anyone trying to pick up a message from space, is knowing exactly what to expect. It is certain that any species sending such a message will be in advance of us technologically because if the message received comes from deep space it must have taken thousands or even millions of years to reach us. The culture that sent it might, by the time it is received, have disappeared, advanced even further or simply become bored with the whole notion. All we can do is to take an educated guess and suppose that for any species there will be commonality in terms of the irrefutable laws of physics.

We may receive a logically repeating mathematical sequence such as pi or a list of prime numbers, it is simply impossible to know. There are sceptics around who suggest that the whole process of looking for such a message is destined to fail, if only because other intelligent species out in space may be so different to us that there would be no points of contact recognizable on both sides. In other words, they may be trying to contact us right now and we simply cannot understand the message.

By the summer of 2004 we were already beginning to reach our own conclusions about how an intelligent species from elsewhere might have already contacted us – humanity simply had not recognized the fact yet. Serendipity being what it is, an article appeared in the August 2004 edition of
New Scientist
. It was written by Paul Davies, a scientist at The Australian Centre for Astrobiology at Macquarie University, Sydney. We found it pleasing that a respected scientist was publicly discussing the idea that an alien culture may have put a message intended for us in place many millions of years ago: a message, that Professor Davies also likens to the plot of the film
2001: A Space Odyssey
.

Whilst congratulating SETI for its efforts to track down incoming messages from space, Paul Davies makes the suggestion that to try and contact humanity by way of radio signals might prove to be fairly unreliable for any alien species far away. He points out that the problem of ‘timing’ might make radio contact difficult, if not impossible. No matter how many such intelligent societies there might be, the chance of them transmitting during the short time slot during which we have been listening is very remote. Is it not possible, Davies asks, whether such a culture, probably immeasurably older than our own, may have conceived of a much more reliable way to let us know of its existence?

Might it not have opted for a method of communication that was not dependent upon transmitting signals for many millions of years in the hope that we, or someone like us, had just evolved the ability to decipher messages in the form of radio waves? Would it not be more likely that our intergalactic cousins would have chosen something much more timeless?

This suggestion, when we read it near the start of Davies’ article, made us sit upright and pay attention because we were already asking ourselves the same question. Davies goes on to suggest that, rather than radio messages, a far more reliable way for any alien species to contact us would be to leave artefacts in the vicinity of planets likely to spawn intelligent life that, given sufficient advancement on the part of such a developing species, it could not fail to recognize.

Then we came across yet more heavyweight scientists with similar, highly logical, thought.

Professor Christopher Rose of Rutgers University in New Jersey and Gregory Wright, a physicist with Antiope Associates also in New Jersey, have stated that the transmission of a radio signal by an extraterrestrial civilization, that would probably have to be detected 10,000 light years away, does not make sense. They suggest that it would be far more efficient to send us some kind of physical message inscribed on physical matter – a kind of ‘message in a bottle’. And, they believe, such a message could already be waiting for us in our own backyard.
²⁴

Rose observed that: ‘If energy is what you care about, it’s tremendously more efficient to toss a rock.’ Once radio signals pass us by they are gone for ever, so aliens would have to beam signals continuously as we have only had radio for a miniscule fraction of our existence as an advanced species.

We had to ask ourselves, what if that physical object was the Moon and the information is there for us to see – once we understand the vocabulary?

If the Moon does hold a message, it would be exactly what Paul Davies called a ‘set and forget’ technique that would survive for millions or even billions of years. Any conventional sort of physical structure, no matter how impressive, would eventually crumble under geological forces, especially on a very active planet such as our own. It turns out that the possibilities for a ‘letter from the stars’ that can survive eons are actually very limited indeed. In the end such a ‘physical’ message needs to be either extremely large or extremely small – and as we were to discover, perhaps both.

We had already uncovered a wealth of published academic material that points to the Moon being the single most important factor in the development and nurturing of complex life forms on the planet Earth. Quite simply, if the Earth is thought of as an incubator for life – the Moon is the carefully programmed machine that monitors and stabilizes the process. A real life-support system.