I wrote the following essay as part of the final assessment for a Saturday-morning course in magazine journalism back in 2002.
Watching the Skies
It is not difficult to be impressed by the Jodrell Bank radio telescope. The huge white dish of the Lovel telescope rises almost ninety metres above the surrounding fields, and is visible for miles across the Cheshire plains. Built in 1957 and recently upgraded at a cost of two million pounds, the telescope has a strangely iconic quality. Like the space shuttle or the International Space Station, it is a prime example of the big science approach of large, multi-disciplinary teams and massive engineering projects that has increasingly come to dominate science over the last fifty years.
Things used to be very different. The 150 or so years prior to the Second World War were the golden age of the amateur scientist/inventor: Thomas Edison invented the phonograph and electric light bulb, and Ernest Rutherford mapped the structure of the atom. In astronomy, wealthy amateurs such as Sir William Herschel in Britain and Friedrich Bessel in Brandenburg (now part of Germany) made formative contributions to optical astronomy; which studies the light emitted by celestial objects.
In 1932, while working on ways to suppress radio interference, an engineer named Karl Jansky found that the clusters of stars that make up the milky way emit radio waves. Professional astronomers treated this discovery, which is now regarded as the beginning of the science of radio astronomy, as a mere curiosity. In 1937, inspired by Janskys discovery, an American amateur radio enthusiast named Grote Reber built a 32-foot dish antenna in his Illinois garden much to the consternation of his neighbours. By 1941, working alone and using completely homemade equipment, he had carried out the first ever radio survey of the cosmos; and laid the foundations for the new science of radio astronomy.
Rebers example of what a determined amateur can achieve with a back yard radio telescope continues to this day. In contrast to the popular image of the amateur astronomer, spending cold nights in the garden or on a hillside, peering through their telescope or binoculars; radio astronomers are both less numerous and lower-profile. This is probably due to two factors. Firstly, the cost (in terms of both money and time) of assembling a basic radio telescope is much greater than that for optical astronomy. Secondly, and perhaps more significantly, the payback is not as immediate. Seeing the moon or a major planet such as Saturn, through a telescope, has a strong and immediate impact on many people. Radio astronomers, by contrast, collect and analyse non-visual readings that may not easily inspire similar enthusiasm.
Nevertheless, there are several thousand amateur radio astronomers active across the world. Many discover the field through an interest in optical astronomy, radio engineering, or information technology. Unlike the early pioneers who used hand-made apparatus, their modern-day counterparts tend to utilise modified equipment bought off-the-shelf, or scavenged from satellite television receivers or junk-yard sales. Cheap and ubiquitous personal computers permit easy data analysis and automatic telescope control things once only available to professional academic astronomers.
Another way in which astronomy, like countless other fields, has changed is through the use of the Internet. Where enthusiasts once worked alone or, if they were fortunate, in sporadic communication with distant collaborators, there are now numerous Internet communities and web sites offering advice and the opportunity to share observations. The early pioneers would no doubt be impressed.
A common criticism of the amateur radio astronomy community is that they are somewhat like recreational bird watchers: they observe and catalogue, but do little or nothing to advance our knowledge of the cosmos. In other words, they are not doing science in the way that professionals do. While this may be largely true the resources available to government-funded big science give it an insurmountable advantage there is one area in which amateurs may be able to match their professional colleagues.
The idea that the galaxy may be home to other intelligent civilisations has long been a theme of popular culture: from H G Wellss War of the Worlds to E.T. and Alien. Since the late sixties, and particularly over the last decade, the search for extraterrestrial intelligence (usually abbreviated to SETI) has been an increasingly respectable topic of research for professional astronomers. SETI was pioneered by the astronomer Frank Drake, who set-out some of its main assumptions in the Drake equation (see further reading). Among these assumptions are that, to be detected, an alien civilisation must have reached a minimum level of technical sophistication and must be emitting some form of signal. For various complex reasons, most astronomers expect that a signal would be in the form of radio waves, and so most SETI efforts to-date have used radio telescopes.
SETI has been compared to searching for a needle in a cosmic haystack. Even if aliens are transmitting signals that we can intercept, we dont know where in the vast galaxy to look, which radio frequency to listen to, or how to recognise the message. The signal may be strong if ET is deliberately trying to make itself noticed, or weak if the thought hasnt occurred to it yet. SETI demands long, patient observation over years or even decades. Professional radio telescopes are expensive to build and run, and are in constant demand for scientific work. Speculative endeavours like SETI usually find themselves taking a back seat to proper work.
This is a great opportunity for the amateur community to make a contribution. Amateur astronomers have the advantage of not having to compete for time on expensive equipment. While an amateurs radio telescope cannot compete on size or sensitivity with those of professionals, a typical three metre dish in conjunction with an easily available radio receiver and a standard PC is capable of detecting a strong signal from nearby stars. And all for less than the cost of a cheap second-hand car.
Stop and think about this for a moment: we live in an age where it is possible for an ordinary individual, acting alone, to acquire the knowledge and equipment to (potentially) uncover the existence of an extraterrestrial civilisation!
Little wonder, then, that SETI has become a very popular activity in the amateur community. Bodies such as the SETI League (www.setileague.org) now coordinate organised searches involving amateurs as well as professionals. Numerous Internet communities and newsgroups exist to discuss the SETI, equipment design, and signal processing software.
Even if they are so far away that we may never physically meet them, the discovery of an alien civilisation would be one of the greatest events in human history. It might be somehow fitting if a lone amateur astronomer, successor of Herschel, Jansky, and Reber, were to make it.
Frank Drake and Dava Sobel. Is there anyone out there? The search for extraterrestrial intelligence. Simon & Schuster, 1991.
Brian McConnell. Beyond Contact: A guide to SETI and communicating with alien civilisations. OReilly, 2001.
Sidebar: Radio Astronomy Facts
- Radio astronomers study celestial objects and events by examining the radio waves that they emit.
- The field of radio astronomy began in 1932 with Karl Janskys discovery that the milky way galaxy emits radio waves.
- The largest radio telescope dish in the world is at the Arecibo observatory in Puerto Rico. It is a colossal 305 m (1000 feet) in diameter.
- Radio telescopes can detect objects such as black holes and brown dwarf stars that are invisible to the human eye with even the largest optical telescope.
- Most astronomers believe that extraterrestrials, if they exist, will attempt to communicate with us using radio waves.