Space Agent and the Ancient Peril (1964), by Angus MacVicar

I encountered this ‘juvenile’ science fiction novel by Scottish author Angus MacVicar in 1966 at the age of ten, about a year into my SF-reading career. You should never judge a book by its cover, but it was hard for me to resist the dramatic image of two men stranded on the top of an erupting volcano, with two flying saucers circling above, and the Moon apparently about to crash into the Earth. But like so many books I borrowed from local libraries as a boy, it subsequently remained lost to me until the coming of the internet.

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Space Agent and the Ancient Peril is the last book in a three-volume series about the UN’s ‘space agent’ Jeremy Grant. The series as a whole is a follow-up to the better-known five-volume ‘Lost Planet’ series which began eleven years earlier when Grant, then aged sixteen, left Australia to join his Scottish uncle Dr Lachlan McKinnon on an expedition to the ‘lost planet’ of Hesikos in the latter’s privately built spaceship. All the stories are written in the first person from Grant’s POV.

In the 1950s, just half a century had passed since the pioneering days of aviation, when the likes of the Wright Brothers, Louis Blériot, and A.V. Roe built and flew their own aeroplanes. It wasn’t perhaps unreasonable to suppose that space travel might develop the same way. But by 1964, when Ancient Peril was published, it was clear that only the two most powerful nations in the world – the United States and the Soviet Union – had the resources to send humans into space. It was utterly beyond the means of Scottish uncles, no matter how brilliant, to build spaceships. Hence we find Jeremy Grant now working for the United Nations. Uncle Lachlan doesn’t feature in this story; neither does space travel. All the action takes place on Earth.

Grant is recovering from a bout of flu when his boss, UN Chief Commissioner Earl Easterman talks him into accompanying archaeologist Spencer Johnson on an expedition to investigate the ancient city of Tiahuanaco on the Bolivian Altiplano. Located a few miles east of Lake Titicaca, the site is attributed to the Inca but it is so remote that only two archaeological expeditions have visited it in the past hundred years. Nobody has been there at all for thirty years. Prof. Johnson has requested Grant’s assistance as he is recognised as the world’s leading authority on space and interplanetary matters. He is interested in the controversial theories of two archaeologists – H. S. Bellamy and Arthur Posnansky.

After meeting in Florida, the two fly to La Paz, where a sympathetic army chief provides a helicopter to transport them to the site, along with a jeep and supplies. The night before the expedition, the helicopter pilot tells Grant that some indigenous people claim that their ancestors had lived in Tiahuanaco millennia ago. Strange godlike men had helped them to build the city, but it was then devastated by a terrible cataclysm.

The helicopter delivers Grant, Johnson, and their equipment to Tiahuanaco without event, and the two set to work. Of particular interest to Johnson is a great megalithic arch known as the Gate of the Sun. He believes that it depicts flying fishes and toxodons – the latter (a hoofed mammal) extinct for twenty thousand years. And how would the Inca have known about tropical flying fish? Johnson has a theory, but he refuses to say what it is. He wants to see if Grant independently reaches the same conclusions.

As Grant is about to articulate his thoughts, the pair are attacked by a group of hostile Urus – indigenous people apparently motivated by robbery. Outnumbered, they are saved by the intervention of a tall man, who commands the attackers to desist and requests that Grant and Johnson accompany him. The man is living in an Uru village about twenty minutes away in the jeep from the site. His house contains an extensive library of books including works by Wells, Steinbeck, Sartre, and Chekhov – but also works by Bellamy and Posnansky on Tiahuanaco.

Grant has any number of questions, but feels unable to ask them, that his thoughts are somehow constrained by the presence of the stranger. Johnson thanks him for his timely intervention, and he is finally able to ask him who he is. The man says that for them to understand they must come with him on a journey to a time when the Earth was at peace. His words become pictures which become a living reality. They are standing on a quay in the port of Tiahuanaco, watching a ship enter the harbour. They have been transported twenty thousand years into the past, when the city lay on the shores of an island and was home to a great civilisation.

Grant and Johnson find themselves dressed in local costume, and able to speak and understand the Tiahuanacan language. They have a basic understanding of the world to which they have been transported: Tiahuanaco is one of twelve island states around the world – others include neighbouring Andea, and to the east are Lemuria, Thule, Hi Brazil, and (of course) Atlantis. Some months earlier, two ‘angels’ named Shamhazi and Azazel with ‘strange eyes’ had arrived in ‘chariots of fire’. These strangers had instigated a building program involving novel architectural techniques and requiring the import of large quantities of andesite (an igneous rock similar to basalt and rhyolite) from the quarries in Andea. Curiously, nobody seems to know just why the project has been initiated – not even council headman Chirguano.

Tiahuanaco is a peaceful, prosperous island state, but divisions are beginning to appear. The building program has made the shipowners and building contractors extremely rich – and greedy. They have banded together to keep wages low and hours long. While a ship is being unloaded of its andesite cargo, an overseer named Caingang assaults one of the dockers. Grant intervenes, and a brawl breaks out. It is abruptly halted when Shamhazi appears and introduces himself to Grant and Johnson. He appears to have stopped the fighting by telepathic command.

The pair accompany Shamhazi to the house he shares with his brother, Azazel. There they also meet a young Tiahuanacan woman named Ishtar, who is running a school for orphan children and has limited telepathic abilities. Grant and Johnson learn that Shamhazi and Azazel are from an Earth-like planet named Ophir. The planet is being affected by increasingly extreme seasonal temperature variations, and by quakes. Its inhabitants decide that they must evacuate to Earth. Advanced parties are sent out to make peaceful contact. Disc-shaped spaceships, powered by nuclear rim jets, are constructed for the purpose (they are identical to a spacecraft designed by Uncle Lachlan which featured in an earlier story).

Soon after their arrival, the Ophir people learn of the existence of a rogue planet named Luna that on several occasions in the past approached the Earth, causing earthquakes, volcanic eruptions, and floods. This last happened ten thousand years ago, but another close approach is due soon. In Tiahuanaco, Shamhazi and Azazel instigate the construction of a quake-proof city with the same architectural techniques used to resist the quakes on Ophir. The scientists of both Earth and Ophir are confident that the effects will be relatively minor and will be withstood by the new cities – but Shamhazi and Azazel are able to pick up the thoughts of somebody who does not agree, a brilliant mind superior to even the best minds of Ophir. The two ‘angels’ want Grant and Johnson to investigate, believing the Tiahuanacans might be more ready to share their thoughts with them than has hitherto been the case. The pair agree to help and are joined by Ishtar.

The group learn that there are only five astronomers in the city – a professor and four lecturers at the University of Tiahuanaco. Ishtar has also learned of an elderly man named Yurucaré, one-time head of the Andea Observatory. He is an expert on Luna, but his theories have long since been discredited. But Ishtar senses that one of the lecturers – a young man named Tamanaque – is holding something back. Grant and Johnson make arrangements with Chirguano to visit University of Tiahuanaco’s observatory.

When they arrive, however, they are told that nobody is available to show them around. Johnson hits on the idea of sending a message to Tamanaque, who replies that he will meet them that evening alone, with the telescope directed at Luna.

Soon after darkness, Grant and Johnson meet Tamanaque, who shows them the telescope. It is second only to the instrument in Andea. Tiahuanacan astronomers are aware of the existence of the planet Neptune and are apparently familiar with Newtonian physics. Through the telescope, Grant looks at the constellations of the Belted Warrior, the Little Toxodon, and the Wry-necked Swan, with Luna prominent in the latter (the Belted Warrior is presumably Orion but it is not clear what if any are the present-day equivalents of the other two; there is nothing resembling a wry-necked bird on the ecliptic near to Orion). Tamanaque then produces a series of unfinished and unverified calculations that suggest that instead of passing Earth, Luna will be captured into a permanent orbit and become a satellite. The gravitational effects of the initial capture will trigger a global cataclysm – in just three days from now. But nobody believes his theory, and he has been forbidden to mention it. Some time earlier, Yurucaré came to similar conclusions. Nobody believed him, and when he would not be silent the Tiahuanacan elite dismissed him from his post and imprisoned him. They feared that his tale of doom would spread panic and jeopardise their lucrative shipping and construction businesses.

At that moment, Chirguano and Caingang burst in, with the intention of arresting Tamanaque. The are accompanied by the Professor, who believes that Tamanaque is mad. With some help from Tamanaque, Grant and Johnson overpower the intruders and tie them up. They force the Professor to tell them that Yurucaré is being held in an underground prison known as the Methane Corridors, located by a natural gas reservoir that supplies the city’s heating and lighting. They have until dawn – when Chirguano, Caingang, and the Professor will be found – to spring Yurucaré from the high-security jail.

This proves ridiculously easy. Grant, Johnson, and Ishtar gain access to the Methane Corridors by climbing down a ventilation shaft. Tamanaque wants to accompany them, but Grant and Johnson insist that his knowledge of Luna makes him too valuable to risk. They soon locate Yurucaré’s cell, overpower a guard, free the elderly scientist, and climb back to the surface. After Yurucaré rests, he and Tamanaque review the Luna calculations in a shelter beneath Shamhazi and Azazel’s house.

The next day, Chirguano and Caingang, accompanied by armed guards, come looking for Grant, Johnson, and the escaped Yurucaré. Shamhazi uses his telepathic powers to convince Caingang that the suspects are not there. Meanwhile, Yurucaré and Tamanaque are still trying to complete and verify the latter’s calculations. Not until evening do they reach a conclusion – and find that the situation is even worse than they believed. Tamanaque’s timing was in error: Luna is approaching ten times faster than he originally supposed, and the capture is just hours away.

Shamhazi summons the citizens of Tiahuanaco to a public meeting, with Grant, Johnson, and Yurucaré in attendance; meanwhile Azazel, Tamanaque, Ishtar, and her pupils head for high ground. A large crowd soon gathers. Grant notices Chirguano and Caingang, who look watchful but take no action. Yurucaré’s warning about the imminent thread serves only to anger the crowd, who are about to riot when the sun sets and Luna is seen to be double its normal size. It is visibly speeding away from the Wry-necked Swan, and growing brighter every second. Shamhazi implores the crowd to come with him to the relative safety of the high ground, where their children can be evacuated to Ophir. But the crowd panics. Most of them rush back to the town to try to retrieve their possessions. Children are trampled in the rush

The group head for high ground. Not until they are halfway up the mountainside do any of the Tiahuanacans heed Shamhazi’s advice and start to follow. Shortly before they reach the summit, winds begin to increase, and the first earth tremors are felt as Luna draws nearer. Both increase steadily as they reach the summit and meet Azazel, Tamanaque, Ishtar, and the orphan children. Azazel tries to make telepathic contact with Ophir to summon help and is eventually successful. By now, volcanoes are erupting in the Andes and the noise of wind and earthquakes makes speech impossible. Tidal waves are sweeping towards Tiahuanaco, where people are still fleeing across the plateau. The whole scene is bathed in the bright-as-day light of Luna.

Grant senses that he and Johnson will not be joining the evacuation. Their time in this world is almost at an end.

Two spaceships arrive from Ophir, their nuclear jets somehow capable of making the journey across interstellar space in a matter of minutes.  Grant and Johnson are forgotten by all but Ishtar, who waves as she boards. The two craft depart, leaving the time-travellers alone on the mountain, as depicted on the book’s cover…

…and then they find themselves back in the home of the stranger who stopped the Urus from attacking them. He explains that the descendants of the evacuees waited for centuries. The moon-flood had destroyed Tiahuanaco and the other island-states, and although they receded and new civilisations eventually arose, these were too warlike to permit a return. Only now, he explains, has ‘the second great flood’ begun to drain and the Earth is again at peace. The book ends abruptly as Johnson asks if the people of Ophir are coming back, and the stranger confirms that yes, now they are.

The story is loosely based on a fringe theory put forward by Austrian engineer Hanns Hörbiger in the 1920s and popularised by fellow Austrian H. S. Bellamy after World War II. The late Sir Patrick Moore said that “it is generally agreed that he was an odd character by any standards”. The theory was known as the Welt Eis Lehr (WEL) or Cosmic Ice Theory. Hörbiger suggested that with the exception of the Earth and the Sun, the whole universe is composed largely of ice. The stars are blocks of ice, and Mars is covered in ice to a depth of 400 km (250 miles). Space is filled with rarefied hydrogen, which results in the orbits of Solar System bodies decaying over a long period of time. The Earth will eventually fall into the Sun, but more immediately, the Moon (also composed of ice) is spiralling in towards the Earth and will eventually share the fate of at least six predecessors. Each of these in turn spiralled ever closer to the Earth, causing violent cataclysms as tidal forces pulled the Earth’s oceans into a ‘girdle’ around the equator. The looming presence of these ice-Moons in the sky gave rise to legends about dragons and the like. As the ice-Moons entered Earth’s Roche limit, they were torn apart by tidal forces. Ice and rock bombarded the Earth, and the relaxation of the tidal stresses around the equator triggered earthquakes and volcanic eruptions. The oceans flowed back to higher latitudes, causing floods around the world. After Hörbiger’s death, Bellamy developed the theory further, postulating that our current Moon arrived in Earth orbit about 13,000 years ago. For some reason, WEL became extremely popular with the Nazis in pre-war Germany; I suppose it could be said that in comparison to some of their other beliefs, Hörbiger’s theory was more-or-less benign.

Angus MacVicar also refers to the Hörbiger theory in an earlier novel, Peril on the Lost Planet, in which the planet Hesikos is threatened by an asteroid.

Tiwanaku (to use the modern spelling) actually dates to around AD 800 and lay at the heart of one of South America’s great pre-Incan empires. But it was once thought to be much older. For example, The World’s Greatest Wonders – published by Odhams Press Limited in London before the war – gives its age as between 12,000 to 14,000 years old. Before the introduction of radiocarbon dating, another Austrian – Arthur Posnansky – spent many years studying astronomical alignments at Tiwanaku. After considering cyclical changes in the Earth’s axial tilt, he calculated that the alignments matched the solstitial sunrise and sunset in around 15,000 BC. The problem with this approach is that so many statues, stelae, and monoliths have been moved around the site or removed altogether that it is just about impossible to reconstruct accurate sightlines and identify solstitial markers.

Posnansky also claimed that Tiwanaku was once a port on the shores of a Lake Titicaca more than 30 m (100 ft.) deeper than it is today, and he investigated structures that he believed were piers or wharves. According to Posnansky, Tiwanaku served as a port for around 5,000 years until a violent earthquake overwhelmed it in the eleventh millennium BC. Subsequent quakes caused Lake Titicaca to drain, leaving Tiwanaku high and dry. Here it is probably simpler to assume that Posnansky’s ‘wharves’ were actually something entirely different than to postulate a geological upheaval that seems to have left no other evidence.

The carvings on the Gate of the Sun (referred to as the Calendar Gate in the book) include a figure holding a staff in each hand; this motif occurs frequently in the iconography of pre-Columbian South America and is thought to represent a weather god. Professor Johnson’s claims that flying fish and toxadons were depicted are popular with ancient civilisation believers and flying saucer enthusiasts, but they are not widely accepted by mainstream archaeologists.

Tiwanaku is certainly not as isolated as MacVicar suggested. Far from only ever having been visited a handful of times, the site has been extensively studied since the mid-nineteenth century. It is a ninety-minute drive from La Paz, and it has been a major tourist attraction since the 1960s.

Space Agent and the Ancient Peril was not that easy to track down, as I could remember only part of the title – Space Agent and the… which told me that it was one of a series of books featuring “Space Agent” but not a lot else. A Google search on the words ‘space agent’ will bring up over 750 million hits including estate agents, NASA, and the European Space Agency. Add ‘Tiahuanaco’ to the search and you will obtain hits on travel agents offering tours of the site. I suspect it was by sheer luck that I tracked down the full title of the book and the name of its author. A further search brought up a picture of the long-remembered cover. I seem to have also been lucky in sourcing a good condition copy at a reasonable price. At the moment, you will not find one for much under £100.

Target Earth!

The name “Project Spaceguard” was deliberately borrowed from the 1973 science-fiction novel Rendezvous with Rama, by Sir Arthur C. Clarke, which describes a catastrophic meteorite impact in northern Italy in the year 2077, as a result of which a global early-warning system is set up to ensure that such a tragedy is never repeated.

Ironically, the real Project Spaceguard was given impetus by a cataclysmic event occurring not on Earth, but millions of miles away, on the planet Jupiter.

However, for the real beginnings of Project Spaceguard, we must go back just over a century, to 1905, when the mining engineer D. M. Barringer and physicist Benjamin C. Tilghman claimed that the Coon Butte Crater in Arizona was caused by a meteorite impact. The suggestion met with considerable scepticism, though it must be remembered that at the time, the idea that meteorites could cause cratering was highly controversial and the majority of scientists believed the craters on the Moon (the only example of large-scale cratering then known to science) had a volcanic origin, a view that did indeed have some support until quite recently. Not until the 1920s was Coon Butte Crater accepted as being meteoritic in origin, since when it has been known, not entirely correctly, as the Meteor Crater.

One of the reasons the impact theory of cratering was slow to win acceptance was because it was rather at odds with the then prevalent doctrine of Uniformitarianism, under which change, both geological and biological, occurs gradually over million years. The idea that large meteorites could wreak enormous changes was reminiscent of Catastrophism, which states that events on Earth such as geological change, the evolution of life and even human history have been shaped by upheavals of a violent or unusual nature.

Catastrophism was not a new idea and until the early 19th Century, it was generally accepted that stories like the Biblical Flood related to actual events. It should be remembered that at this time the Bible was interpreted more literally that is usual now and it was widely believed that all life on this planet had been created exactly as described in the Book of Genesis. Such beliefs had largely died out after Charles Darwin put forward his Theory of Evolution and fossil evidence confirmed that life had evolved gradually over millions of years.

It was easy to be complacent at that time. The Arizona crater and others that came to light later were thousands and in some cases millions of years old; and the face of the Moon has not changed throughout recorded human history. Not for many decades would it be discovered that cratering exists on many other bodies in the Solar System. Yet the danger signs were there for those who cared to look.

On the morning of 30 June, 1908, a fragment of cosmic debris entered Earth’s atmosphere somewhere over western China. Travelling eastwards on a shallow slanting trajectory, it trailed a series of loud explosions in its wake until at 14 minutes and 28 seconds after seven o’clock local time, by which time it was around 5-10 kilometres above the ground, it exploded near the Tunguska River in Siberia releasing energy that has been conservatively estimated at 10 megatons and could have been as much as 20 megatons. The airburst felled around 80 million trees over an area of 2150 square kilometres and even now, a century after the blast, satellite imaging shows reduced tree cover in the area around ground zero. Curiously no trace of the object has ever been found, which has lead to speculation that it was a small comet rather than an asteroid (inevitably there have been suggestions of a more speculative nature such as black holes, antimatter and of course crashing UFOs). Fortunately, the region was largely uninhabited, and casualties were restricted to a dozen or so nomadic tribespeople who were slightly injured. But had the meteorite arrived 4 hours 52 minutes later, the city of St. Petersburg would have been totally destroyed, together with most of its inhabitants who at that time included one Vladimir Illich Ulyanov, later known as Lenin. Just a few hours, and the history of the 20th Century might have been very different!

In October 1937, Earth experienced an event we now know to be commonplace, but at the time caused some consternation when the news became public. The asteroid 1937 UB, later named Hermes, passed by at less than twice the distance of the Moon. Hermes was large enough to have caused a global disaster had it hit Earth. Hermes caused such a stir that it was given a name despite being lost after its close passage; it was not relocated until 2003 and is now known to comprise two 300-metre objects separated by just 1200 metres. It has also been calculated that it came even closer to Earth in 1942, but it was missed. At the time, of course, many astronomers would have been otherwise engaged.

In February 1947, a meteorite exploded just over two hundred miles from Vladivostok, detonating above the ground like the Tunguska object though in this case specimens from the fall were recovered. Although the explosive yield in this case was much less, it was still at least five times more powerful than the nuclear bombs dropped on Hiroshima and Nagasaki eighteen months earlier.

Both the Siberian events took place over sparsely populated regions, but then on 10 August 1972 came a decidedly close call, when an asteroid approximately 10 metres in diameter entered Earth’s atmosphere above southern Utah. Travelling due north, it passed over Salt Lake City, before making its closest approach to Earth at an altitude of around 53 kilometres above Montana, where sonic booms were heard. Still travelling above escape velocity, the body then drew away, exiting the atmosphere over Canada.

Had it come a tiny fraction closer, it would have impacted with multi-megaton effect in the densely populated region between Provo, Utah and Idaho Falls. In the prevalent tensions of that era, and before the threat of meteorite strikes was fully appreciated, such an explosion could easily have been mistaken for a nuclear attack and triggered World War III.

Scientist had in fact been warning of the danger since the war, but they have been largely forgotten – few, for example, will have read the 1953 work Target Earth, by Allan Kelly and Frank Dachille, who advocated the use of rocket powered “tug boats” to deflect incoming meteorites. However in the 1980s the first concrete evidence of a meteoritic catastrophe on this planet began to emerge – albeit concerning events occurring millions of years before the dawn of mankind.

The sudden demise of the dinosaurs, 65 million years ago, had long been a mystery to science. Incidentally, it is worth pointing out a few common misconceptions about the dinosaurs. They were never contemporaries of man, despite suggestions to the contrary by one or two rather silly Hollywood motion pictures: they were not all large and ferocious, the majority being much smaller than a man: and finally, they certainly were not the stupid, blundering creatures of popular belief. They were the unchallenged rulers of the Earth for 150 million years. If mankind hopes to emulate the feat there is a long way to go.

In June 1980, the physicist Luis Alvarez, his son Walter and a number of other collaborators published a paper which claimed that a large meteorite had struck the Earth 65 million years ago, resulting in the extinction of the dinosaurs. The evidence for this claim was based on studies of a layer of clay, half an inch thick, laid down between two layers of limestone that had been seen in rocks near the town of Gubbio, in northern Italy. The clay was clearly located at the so-called K-T Boundary that delimits the Cretaceous and Tertiary geological time periods. There was no element of doubt; the limestone below the clay contained Cretaceous fossils; that above contained fossils from the Tertiary. It was at this point in time that the dinosaurs had become extinct.

The Alvarez team has originally intended to find out how long it had taken the clay to be deposited, because sudden though the transition from Cretaceous to Tertiary was, nobody believed it could have literally happened overnight. The method chosen was to measure the amount of iridium in the clay.

Iridium is one of the so-called “Splendid Six” group of metals, which also includes platinum, and is considerably rarer than gold. It is very rare in the Earth’s crust, but relatively abundant in meteorites. There is nothing mysterious about this. Because of the great density of these metals, much of the terrestrial supply has sunk right down to the Earth’s core. However, meteorites are formed from much smaller parent bodies in which the iridium is more evenly distributed.

A constant trickle of iridium reaches Earth all the time among the dust grains which constantly rain down from outer space as a result of micrometeorites entering the atmosphere. The rate of fall has been constant throughout geological time, the amount falling over, say, 100 years being the same now as it was 65 million years ago. This effect could be used to provide a “clock” to time how long it had taken the clay layer to form.

The Alvarez team had expected to find a small amount of iridium, consistent with, at most a time scale of 10,000 years to deposit the clay, which is what one would normally expect for a layer of its thickness. Instead, they found iridium concentrations were so high that if the “iridium clock” model were correct, it would have taken four million years for the clay to form.

This result was clearly nonsensical. Something else must have produced the anomalously high iridium levels and the only possible causative agent was a large meteorite, which had smashed into the Earth, spreading billions of tons of fine dust around the world comprising pulverised rock and debris from the meteorite itself. This fine dust eventually settled out of the atmosphere to produce a uniform layer of iridium-enriched clay all over the world. The shroud of dust, encircling the globe, would have cut off the light of the Sun and plunged the Earth into darkness. Plant life would have died off, unable to photosynthesise, and temperatures would have fallen. It was this “cosmic winter” that had killed off the dinosaurs.

One consequence of this discovery was the realisation that a “nuclear winter” would follow even a limited nuclear exchange. This led to the signing of several major arms treaties by the end of the 1980s and for a time there were genuine hopes that the madness of nuclear weapons might finally be eliminated. Sadly, these hopes seem to have been misplaced, with many states scrambling to acquire weapons of mass destruction, including nuclear weapons.

Like all radical scientific theories, the impact theory of the dinosaur extinction was slow to gain acceptance, especially from the palaeontologists who felt their territory had been invaded by a bunch of physicists and geologists. Some geologists put forward a rival theory, claiming that a series of volcanic eruptions occurring in India at the same point in time had been responsible. They argued that the volcanoes, spewing forth material from the bowels of the Earth, could have produced the iridium anomaly.

Meanwhile, the search was on for the “smoking gun”, the crater left by the impact. In 1990, a huge buried crater at Chicxulub, in the Yucatan Peninsula in Mexico came to the attention of scientists. The crater had been formed in what had then been shallow water and consequently was covered in a limestone layer. It had been discovered by industrial geologists in the 1970s, but they had kept quiet about their discovery because of the possibility of oil in the region. Using radioactive argon dating techniques, the scientists determined that the crater had been formed 65 million years ago – the time at which the dinosaurs disappear from the fossil record.

In the light of this evidence, the impact theory has now become widely accepted. A giant meteorite impact killed the dinosaurs, and indeed 70 percent of all species then existing on Earth. But what was disaster for the 70 percent was good news for the rest, including the tiny shrew-like mammals, which were able to fill all the vacant niches and diversify into the vast range of modern mammals, including ourselves, that now inhabit the Earth.

Interesting though all this was, it had all happened rather too long ago for the threat of a recurrence to be taken seriously by the general public, and what finally moved the danger from cosmic impacts onto the public agenda was a timely demonstration of just what such an impact could do. Fortunately, Nature was kind enough to arrange for the demonstration to take place at a safe distance from the Earth!

In 1993, a team of comet watchers comprising Carolyn Shoemaker, her husband Eugene Shoemaker and David Levy, observing at the Mount Palomar Observatory, discovered a peculiar cometary object subsequently named Shoemaker-Levy 9 (it was in fact the team’s ninth discovery). Shoemaker-Levy 9 resembled a string of beads strung out on the same orbit and once its orbit had been calculated, it was determined that it was the remains of a single comet that had passed so close to Jupiter the previous year it had not only been captured by the giant planet, it been torn apart by tidal forces during its close approach. Furthermore, it soon became clear that the cometary fragments were now on a collision course for Jupiter, with a series of impacts due to begin on 16 July 1994.

What followed is of course well-known. Although all the impacts occurred on the side of Jupiter not facing the Earth, the fireballs produced as the fragments rained down upon the giant planet billowed up to 2000 miles above the cloud-tops and were clearly observed by the Hubble Space Telescope. The impact sites, carried into view by Jupiter’s rapid rotation, showed that great dark scars had been produced. The dramatic photographs of the scars, stretched out across the face of the wounded planet convinced even the politicians the threat posed to Earth by such objects was very real, and even while the bombardment of Jupiter continued, the US House of Representatives passed a bill requiring NASA to submit to the Congress a costed proposal to chart all objects in Earth-crossing orbits larger than one kilometre in diameter. There were similar political initiatives in Europe, Russia and Australia.

Meanwhile, Hollywood wasted no time in leaping on the bandwagon, and in the late 1990s “meteorite movies” almost become a genre in their own right, though for the most part they were little better than the dire (and misnamed) Meteor, which was released in 1979. A scene from one such movie shows the inundation of New York by an impact-induced tsunami; ironically (in the light of later events) only the twin towers of the World Trade Center survive.

To implement a scheme to monitor space for hazardous objects, it was proposed to set up a global network of eight purpose-built telescopes. Six would have an aperture of 100 inches, and would be used to search for near-Earth objects. The other two, one in each hemisphere, would have an aperture of 200 inches and would be used to search for faint comets beyond the orbit of Jupiter.

By the end of the century a hazard scale for potentially threatening near-Earth objects had been devised. Known as the Torino Scale (named for Torino [Turin], Italy, where it was first proposed), it accesses a threat from 0 (no possibility of collision) through to 10 (the end is nigh). Threat level is based on both probability of a collision, and the consequences of that collision. The latter is obviously a function of the size of the threatening object.

What action could be taken if an asteroid was determined to be on a collision course? Simply blowing it up with a nuclear device would do no good – the fragments would still hit Earth with disastrous consequences, but given sufficient lead time, danger could still be averted by deflecting the threatening object. Two methods have been proposed. The first is to use the enormous velocity of such objects relative to the Earth to deflect them. By firing a large interceptor rocket into the path of one, the change of momentum so imparted would be sufficient to nudge it onto a new, harmless trajectory. With ten years warning, objects a mile in diameter could be so diverted. However, with only the same warning, much larger objects up to 20 miles in diameter could also be diverted by exploding one or more nuclear devices a short distance away, so as to vaporise the surface of one hemisphere. In this case, the expanding gases would act as a rocket motor and push the object away from the direction of the blast. With a century to react, even objects the size of a small moon could be turned aside.

Unfortunately, politicians being politicians, the initial enthusiasm for Project Spaceguard seems to have been lost: global warming seems to be the hot (pun intended) topic now. One sincerely hopes that the project does eventually come to fruition, because it is a matter of pure luck that no impact having global consequences has occurred during recorded history; and the respite can hardly be expected to continue forever. Inevitably, there has been speculation that such an impact did occur in late prehistoric time.

The idea isn’t new and the suggestion that astronomical events have caused global catastrophe within the last ten thousand years have been the subject of speculation for decades, though most of which is firmly in the realms of pseudo-science. The best known proponent of this view was Belarus-born Emmanuel Velikovsky, who had a number of very strange ideas, including the belief that Venus was a comet until just a few thousand years ago. In 1950, he published a book called Worlds in Collision in which he meticulously catalogued graphic accounts of global catastrophe as described in the Bible; the records of the Mayan, Aztec and Inca civilisations; and Greek and Nordic mythology. Velikovsky’s approach was to assume that these myths and legends were literally true, and he sought to interpret them as being references to catastrophes caused by close encounters first with Venus and then Mars, occurring around 2000 BC and 800 BC. Worlds in Collision unleashed a storm of Salman Rushdie proportions in the scientific community, and there were even threats by some universities to boycott Velikovsky’s publishers unless the book was withdrawn. This ridiculous over-reaction only served to lend the book spurious credibility, with the result that it continues to find its way into pseudo-scientific speculations to the present day.

Velikovsky’s book is very readable and well-researched, and one wonders how many of his critics have ever actually taken the trouble to read it. That said there is no doubt that the theory he puts forward is the purest nonsense and suggests a near-total disregard for the laws of physics. Had Venus genuinely been on a collision course for Earth it would have taken rather more than a lightning bolt (as Velikovsky asserts) to avoid total annihilation; and had its influence halted the Earth’s spin the effects would not have been confined to the walls of Jericho.

Worlds in Collision didn’t even represent the full extent of Velikovsky’s bizarre theories and among the speculations that never made it into print was the idea that Earth had once been a satellite of Saturn, but a nova-like disturbance there had shifted our planet into its current orbit, producing Noah’s flood in the process; Jupiter was to blame for the destruction of Sodom and Gomorrah; and Mercury was somehow mixed up in the Tower of Babel.

Stephen Jay Gould makes what is probably the fairest comment on Velikovsky. In an essay entitled Velikovsky in Collision, he stated Velikovsky is neither crank nor charlatan — although to state my opinion and to quote one of my colleagues, he is at least gloriously wrong. But is the idea of a global catastrophe in Neolithic or Bronze Age times something we can completely dismiss?

In 1982 the British astronomers Victor Clube and William Napier proposed that large comets can from time to time end up in short-period orbits and wreak havoc in the inner Solar System. Over time a large object would break up and Earth would experience not just impact events but global cooling arising from meteoroidal dust building up in the atmosphere. The theory met with considerable scepticism at first but was widely quoted in the spate of books on the “meteorite menace” that appeared in the second half of the 1990s. Speculations in these books included the suggestion that the collapse of Mycenaean civilization towards the end the Bronze Age had been caused by an impact, an idea that certainly does deserve to be taken very seriously. However attempts to link more or less every myth and legend (including of course Atlantis) to meteorite impacts; and the suggestion by one author that Stonehenge was a Neolithic early-warning system, intended to look out for incoming meteorites; should serve as a reminder that there is a fine dividing line between informed speculation and pure hokum.

One possible reference to a prehistoric catastrophe is to be found in the Norse legend of Ragnarok, the end of the world, which tells of a world fire followed by the Fimbulvetr, a great winter lasting three years. This is startlingly suggestive of a meteoritic impact followed by a “cosmic winter” of the kind associated with the death of the dinosaurs.

But are the Norse legends, as compiled by Snorri Sturluson in the Prose Edda, based on original material? Many have commented on the similarity between the opening of the Sixth Seal in the Book of Revelation and the Norse account of Fenris-Wolf devouring the sun. It has been pointed out that the Prose Edda was compiled from a Christian standpoint. Could the Ragnarok legend not simply be a rehash of the Biblical account of St. John the Divine?

In the early Thirteenth Century, the ancient Norse legends were becoming rather frowned upon because of the rise of Christianity in the Scandinavian countries and Snorri Sturluson decided to record these wonderful and now all too often neglected tales for posterity. It is true that he was a Christian, but the considered opinion is that he did not embellish the Ragnarok legend with Biblical material and that it is largely unaltered from its original form, and of independent origin. So could the Ragnarok legend be an account of real events?

The last Ice Age ended around 10,000 years ago, but the thaw set in some millennia previously. This was interrupted by an event known as the Younger Dryas occurring 12,700 years ago and lasting for 1,300 years. It has recently been suggested that this might have been the result of a meteorite impact near the North American Great Lakes. Of course the Norse legends are far more recent in origin – but it is possible that some elements have their origins in these events millennia early, just as the universal Flood mythology probably has its origins in the rise in sea levels that accompanied the end of the last Ice Age. However I have to say I am somewhat sceptical – I do feel that it is far more likely that the Younger Dryas was caused by freshwater running off from the melting North American ice sheets. This could have caused the Gulf Stream to cut off, bringing a temporary halt to the warming. If the Ragnarok legend does relate to actual events, possibly it is a description of a major volcanic eruption. This could also precipitate temporary global cooling, such as happened in 1815 after the eruption of Mount Tambora. One eruption that undoubtedly made its mark on prehistory is that of Thera in the Mediterranean around 1600 BC. This seems to have brought about the downfall of the original Minoan civilization on Crete and its absorption by the mainland-based Mycenaeans.

While it is possible that a major meteorite impact gave rise to some of the Norse legends, the evidence is sketchy and the idea of a late prehistoric impact still largely speculative, unlike the K-T Boundary event, which few now dispute was caused by a meteorite. What is not speculation is that the next major impact will occur one day. It may be a hundred millennia away or just a few days. Let us hope that the latter is not the case, for it may be many years before a proper early warning system is in place.

It seems to be human nature to react to tragedy rather than try to prevent it from happening in the first place. Less than a century ago, major transatlantic liners sailed quite legally with sufficient lifeboats to save only a fraction of those aboard should disaster strike. Today it is quite unthinkable that a ship should sail without lifeboats for all. The story of the Titanic is indelibly etched on mankind’s collective psyche. Unfortunately, the needless loss of human life has continued unabated. For example, it took the deaths of nearly two hundred football fans in three separate disasters in the 1980s before something was done about the medieval conditions in which enthusiasts were expected to follow their teams.

Even a small meteorite strike on a major city would pale all this into insignificance. The death toll would far exceed that of the terrorist attacks of 11 September 2001, possibly running to tens or even hundreds of thousands. Even if a warning was given and there was sufficient time for the affected region to be evacuated, it is also worth considering the cultural heritage that would be lost should a meteorite land in the middle of Paris, Rome or any one of a dozen other European cities. The annihilation of the Louvre, the British Museum or the Hermitage would be a disaster comparable to the destruction of the Alexandria Library in antiquity.

Let us hope it does not come to that….

© Christopher Seddon 2007