by Duncan Lunan

In April 1973 the British Interplanetary Society published my article ‘Space Probe from Epsilon Boötis?’,1 which was based on the mystery of long-delayed radio ‘echoes’  (LDE’s), first reported in the 1920’s.

Actually, the ‘echoes’ were much too powerful to be simple reflections of signals from Earth.   Experimenters studying round-the-world propagation of radio waves found their outgoing pulses were being returned to them with a delay of three seconds, as if they were being amplified and returned by something at the distance of the Moon – but definitely not the Moon itself.  In later experiments the delay times began to vary upwards from three seconds, in increasingly complicated sequences, but with no variation in intensity – still indicating a single source amplifying and returning the pulses.

Prof. Ron Bracewell of Stanford suggested in 1960 that the ‘echoes’ might have been rebroadcast by an unmanned probe from another civilisation, trying to attract our attention, and in 1972 I worked out a ‘translation’ of the 1920’s echo patterns.  The variations of delay times appeared random;  but Prof. Bracewell himself had suggested the first signal from such a probe might be a star map, and the stars are spaced at random in the sky.  I tried plotting the delay times against the order in which the echoes were received  (Fig. 1A), and at only the second attempt I found what looked like a star map – in which it appeared that the probe had come from the double star Epsilon Boötis, in the constellation Boötes, the Herdsman  (Fig. 1(B)).  Arcturus, the brightest star in the constellation, seemed to be out of place in the map;  but on checking, was shown at its place about 13,000 years ago.

Apparent ‘Epsilon Boötis Signal’, spelled out in Long-Delayed Echoes Fig 1A

Other parts of the supposed message seemed to give the scale of their planetary system, orbiting Epsilon Boötis A, and seemed at first to make sense.  Epsilon Boötis A is an orange giant star, and the translation indicated that the probe makers had evolved on its second planet, emigrating later to the sixth when their sun began to expand.  That indicated that Epsilon A had been an F6 star during its stable lifetime, and as I wrote in ‘The Fermi Paradox’ Part 3, on May 8th, F-star civilisations have a strong incentive to move by the time they reach our stage of development.  But there was a problem:  the companion star  (Epsilon B)  was bright blue, apparently a short-lived sun of spectral type A2.  It emerged that the distance given for the star in most reference books was too low, and at the true distance of 203 light-years, Epsilon B really was an A2 star and the orange giant Epsilon A had been an A0, like Sirius – too massive and with too high a radiation output to sustain habitable planets, too short-lived for life to have evolved there.  At the same time, more accurate 1920’s records were located, and most of the ‘star map’ translations were ruled out – not the ‘Epsilon Boötis’ one, but it too had to be treated as suspect.  I withdrew the entire translation,2 but now it seems I may have gone too far.

Fig 1B

Dropping it didn’t rule out the space probe suggested by Prof. Bracewell  (though he himself abandoned the idea).3  James Strong of the British Interplanetary Society had suggested that the probe could be located in either the ‘Lagrange 4’ or ‘L5’ point, also called ‘Trojan’ or ‘Equilateral’ points, equidistant from the Earth and Moon.The dates and times of the 1920’s LDE’s showed that the L5 point was at least one source of the effect.5  Anthony Lawton of the BIS suggested that in ideal conditions the Trojan points could form temporary, stable ionospheres of their own which would generate LDE’s;6  it was reported that I accepted that, but scientists I consulted replied that such clouds would be disrupted by currents in the Earth’s magnetosphere, or at other times of the month by the Solar Wind, the constant outflow of charged particles from the Sun.  In any case, as the Lagrange points have no gravitational fields of their own, a cloud of charged particles would be scattered by their mutual electrostatic repulsion – unless there was a powerful magnetic or electrostatic field to hold them in place.  If this was produced by a spacecraft, I suggested, Lawton might have hit upon the method by which the Bracewell probe generated LDE’s – by accident!

Many books and articles said that Lawton conducted an active radio search for LDE’s, but in reality he stopped after getting an initial ‘reply’, on the grounds that further transmissions “would constitute a biassed experiment”.  Optical searches of the Lagrange points by others failed to find anything as large as the Skylab space station, or, in a later search, as large as the Pioneer 10 space probe.7 Meanwhile, however, Epsilon Boötis just would not lie down.

There are several real or suggested Zodiacal star maps, laid out on the ground, which centre on Boötes.  That’s just because the constellation lies near the pole of the Ecliptic, perpendicular to the Earth’s orbital plane around the sun, so any Zodiacal map will be centred near it.  But also, we are in Boötes as viewed from Tau Ceti, one of the nearest stars like our Sun, and at relativistic speeds, Epsilon Boötis would be a prime navigational reference on the journey here.And there was an even stranger development.

After my book Man and the Stars came out,9 I was contacted by Alan Evans  (see his obituary here last week), who liked the analysis I’d made of Erich von Däniken’s claims, where I concluded that Earth had not been visited more than four times, at most.  Alan suggested we jointly attempt something still more systematic:  if the Earth had ever been visited, our aim would be to find proof.  

We tightened up my approach into four categories of possible evidence.  Category A would be our objective, an artefact of unquestionably extraterrestrial origin.  Category B would be optical or electromagnetic anomalies pinpointing such an object  (like the Tycho monolith in 2001, A Space Odyssey);  Category D would be the ‘von Däniken material’ of legends, drawings etc. which were no use except in suggesting areas to search for other types of evidence.  But Alan pressed me to include a new category, C, which would be anomalous astronomical alignments in man-made structures – anomalous because they revealed knowledge which the builders should not have had.  For example, on high-resolution photographs of Stonehenge, he had identified markings which seemed to indicate Galactic alignments.

I wasn’t impressed at first.   I had studied megalithic astronomy under a leading expert, Prof. Archie Roy, and seen nothing unusual;  there was no correlation even with Category D;  and when I did the calculations, the markings Alan had found didn’t seem to be Galactic.  At the time when he put this to me, circa 1975, it was supposed that Stonehenge I was built in 1800 BC, near the end of the Stone Age in Britain  (not many people realise that Stonehenge was one of the last megalithic rings), with Stonehenge III, the inner circle, still later in the Bronze Age.  Soon afterwards, however, Archie Roy himself published an article from which we learned that the radiocarbon dating scale had been revised, pushing Stonehenge I back from 1800 BC to 2700 BC.10  Further revision made it c.2840 BC, and that radically changed the whole position.

Archaeoastronomy at Stonehenge.

Fig 2A

Fig. 2A shows the celestial sphere as viewed by an observer in the northern hemisphere.  The altitude of the pole above the northern horizon is equal to the observer’s latitude, and the heavenly bodies circle around it, parallel to the equator, with the daily rotation of the Earth.  The altitude of a body above the horizon, and its azimuth measured along the horizon from the north point, change constantly as the Earth turns.  Apart from the circumpolar stars, which are too near the pole to rise and set, everything else rises in the east and sets in the west at a position which is determined by the declination of the object, measured from the equator  (Fig. 2B).  Where the declination equals the observer’s latitude, the star passes overhead once a day.

Fig 2B

Horizon positional astronomy was all the Stonehenge builders could do  (Fig. 3).  Stonehenge I incorporated the ditch, bank, Avenue, Heelstone and Station Stones;  what most people think of as ‘Stonehenge’ are the great sarsen archways of the inner circle, Stonehenge III, erected in the early Bronze Age.  It’s universally agreed that the Stonehenge Avenue and the later structure both mark the midsummer sunrise.  But few archaeologists agree with Gerald S. Hawkins that the ‘Station Stones’ of Stonehenge I mark the extreme positions of the Moon’s 18.6 year cycle;11  and still fewer with Prof. Alexander Thom, that the megalith builders had a sophisticated programme of lunar observatories, spread over the British Isles.12  Personally, I’m convinced;  I’ve even built a modern megalith, under the auspices of Glasgow Parks Dept., to compare its performance with the prehistoric sites, and demonstrated that high precision could  have been achieved by naked-eye observations.13

Fig 3

When it comes to star alignments, the position is more complex.  Because the Earth’s equatorial plane doesn’t coincide with the Ecliptic, nor with the orbit of the Moon, the combined pulls of the Sun and Moon on Earth’s equatorial bulge cause the Earth’s axis to ‘wobble’ around the Ecliptic Pole with a period of 26,000 years  (Fig. 4).  13,000 years ago the north pole star was Vega in Lyra, and 5,000 years ago it was Thuban in Draco, at the time of Stonehenge I.  The pull makes the equator move around the Ecliptic, constantly changing the position of the Vernal and Autumnal Equinoxes  (Precession of the Equinoxes).  As a result a star’s declination is constantly changing – likewise its Right Ascension, which is measured from the Vernal Equinox along the equator, in the same direction as the Sun’s motion on the Ecliptic shown by the arrows in Fig. 2(B).

Fig 4

Astronomers can partly get round the problem of coordinate change by giving star positions in Ecliptic Latitude, which remains constant, and Ecliptic Longitude, which changes smoothly with time.   But for coordinates which are fixed over human time-spans, even the spans of civilisations, we have to use Galactic Latitude and Longitude, whose zero point is the Galactic Centre and whose pole is on the perpendicular to the central plane of the Milky Way  (Fig. 5).

Fig 5

On the high-resolution photographs of Stonehenge, Alan Evans pointed out a curious horseshoe-shaped marking on the northwest, cutting the bank and overlying Station Stone 93  (Fig. 3).  It’s not on official plans and may not be significant:  the photos were taken in 1966, eight years after one of the fallen trilithon archways was re-erected, and the ‘horseshoe’ coincides at least in part with the tracks of the heavy machinery used then.  We have located a smaller version of it in a prewar aerial photo, but it’s still historically suspect.  Still earlier photos, taken by balloon, show a similar but different pattern.11  But the relationship the horseshoe pointed out to us was real enough.

As Fig. 3 shows, the orientation of the horseshoe is to the rising point of the Galactic Centre, and of the Galactic Equator’s intersection with the Ecliptic, c.2840 BC.  Even more extraordinarily, it turns out that the declination of the North Galactic Pole was then equal to the latitude of Stonehenge.  Consequently, when the Galactic Centre was on the horizon, the Galactic Pole was in the zenith and the Galactic Equator coincided with the horizon  (Fig. 6).

Fig 6

It would be remarkable if that was a coincidence, but if it’s not coincidence, it’s an extraordinary finding.  The Galactic Centre is 27,000 light-years from us and hidden behind dense clouds of absorbing dust in the inner regions of the Milky Way, so its location cannot be pinpointed visually, only with a radio telescope.  Until you know exactly where the Centre is, you can’t determine the true plane of the Galactic Equator and the true positions of the Galactic Poles.  At the Moscow General Assembly of the International Astronomical Union in 1958, new values for the positions of the poles and the Centre were officially adopted, based on the distribution of neutral hydrogen in the inner Milky Way and study of the radio source Sagittarius A*.  Previous optical studies had suggested the Centre was in Scorpius, so it was a big change.  Maps using the old Galactic coordinates were still on sale as late as 1963, with addenda giving corrections to the new system.14 Yet apparently the builders of Stonehenge knew exactly where the Galactic Centre was, or took their cue from something or somebody who did.

In this context, why are Galactic coordinates so important?   Imagine a spacecraft travelling between the stars.  Its attitude sensing platform might be oriented to its home world – its own Right Ascension and declination – or its home planetary system, its own Ecliptic coordinates.  But neither will be relevant when it enters our Solar System:  the only coordinate system common to its system and ours is the Galactic one.  In any manoeuvres or landings it made here, you would expect it to navigate in Galactic coordinates;  and if it chose a landing site on the declination of the Galactic pole, then once a day the azimuth and altitude of any star, measured from the rising point of the Galactic Centre, would correspond to its Galactic coordinates, like B’s in Fig.6.  If the spacecraft’s attitude-sensing platform was fixed, built into its structure, it would still be correctly lined up with the sky once a day.

So if the horseshoe marking is modern, its ‘prehistoric’ alignment might be a curious coincidence.  What looks more likely, on Fig. 3, is that there was something in the centre of Stonehenge I, which was gone by the building of Stonehenge II and III.  In fact, after Stonehenge I was built, around 2700 BC the site was abandoned for over 200 years while the same neolithic people built the much larger complex of Avebury and Silbury Hill, due north of Stonehenge itself.15

What would annoy most archaeologists, who don’t even admit most ‘conventional’ archaeoastronomy, is the suggestion that the Stonehenge orientation is Galactic at all.  I looked for an optical marker, something which would have let the builders create Stonehenge without knowing about Galactic coordinates or even without a spacecraft necessarily being there.  And I found one, but it didn’t exactly make the alignments less controversial.  The star which had the same declination as the North Galactic Pole in 2840 BC, equal to the latitude of Stonehenge, was Epsilon Boötis itself.

It was so hard to believe, when I’d abandoned the Epsilon Boötis ‘translation’ of the radio patterns, that I arranged to see for myself, twice in the planetarium of the Jewel & Esk College in Musselburgh, then all over again at the much larger one in Armagh, later still at Glasgow Nautical College and then at the Glasgow Science Centre.  It feels extraordinary to see such findings, worked out with long pages of calculations, simulated on the planetarium ‘sky’ overhead.  With the date set for 2840 BC, at the Stonehenge latitude, the Milky Way really does line up with the horizon once a day and Epsilon Boötis really does go through the zenith as well, earlier each day.  And it it’s all an extraordinary set of coincidences, then they don’t end there.

(To be continued)


1.  Duncan Lunan, ‘Space Probe from Epsilon Boötis’, Spaceflight, 15, 4, 122-131  (April 1973).

2.  Duncan Lunan, ‘Long-Delayed Echoes and the Extraterrestrial Hypothesis’, Journal of the Society of Electronic and Radio Technicians, 10, 8, 180-182, September 1976.

3.  Ronald N. Bracewell, ‘Manifestations of Advanced Civilisations’, in John Billingham, ed., Life in the Universe, MIT Press, 1981.

4.  James Strong, Flight to the Stars, Temple Press, 1965.

5.  George Sassoon, ‘A Correlation of Long-Delay Radio Echoes and the Moon’s Orbit’, Spaceflight, 16, 7, 258-265, July 1974.

6.  Anthony T. Lawton, Sydney J. Newton, ‘Long Delayed Echoes:  the Search for a Solution’, Spaceflight, 16, 5, 181-187, May 1974.

7.  Robert A. Freitas, Jr., Francisco Valdes, ‘A Search for Natural or Artificial Objects Located at the Earth-Moon Libration Points’, Icarus,42, 442-447  (1980);  ‘A Search for Objects near the Earth-Moon Lagrangian Points’, Icarus. 53, 453-457  (1983).

8.  James R. Wertz, ‘Interstellar Navigation’, Spaceflight, 14, 206-216, June 1972.

9.  Duncan Lunan, Man and the Stars, Souvenir Press, 1974.

10.  Archie E. Roy, ‘Saturday Extra:  Prehistoric Lifestyle in Doubt’, The Glasgow Herald, September 27th, 1975.

11.  Gerald S. Hawkins, Stonehenge Decoded, Souvenir Press, 1966;  “Beyond Stonehenge”, Hutchinson, 1966.

12.  Alexander Thom, Megalithic Sites in Britain, Oxford University Press, 1967;  Megalithic Lunar Observatories, OUP, 1971;  (with Archie S. Thom), Megalithic Remains in Britain and Brittany, OUP, 1978.

13.  Duncan Lunan, ‘Solar Events at Sighthill’, Griffith Observer, 50, 6, 2-11, 20, June 1986;  The Stones and the Stars, Building Scotland’s Newest Megalith, Springer, New York, 2012; ‘Sighthill Observations’, Orkney News, April 10th 2022.

14.  J. Gall Inglis, Arthur P. Norton, Star Atlas, 14th edition, Gall & Inglis, 1959.  The new Galactic co-ordinates were not substituted until the 16th edition in the 1970s.

15.  Dates for the various construction phases at Stonehenge have been in some dispute;  Aubrey Burl, Prehistoric Avebury, Yale University Press, 1979, puts the earliest construction around 2800 BC, as do the Thoms  (ref.12), with no further work until c.2150 BC.  Some subsequent reports compress the building into one continuous process;  yet there seems to be clear evidence for an interruption, during which the Stonehenge I ditch silted up, although its discoverer put the event strangely far back, dating it at 3100 BC, well before the starting dates given elsewhere.   (Christopher Chippendale, ‘Life around Stonehenge’, New Scientist, 101, 1404, 12-17, 5 April 1984).  More recently Francis Pryor states that work on the ditch began as early as 3300 BC, with more systematic work including the creation of the Aubrey Holes c.3000 BC, and placing of the bluestones from Wales around the perimeter c.2900 BC.  (Frances Pryor, Stonehenge, The Story of a Sacred Landscape, Head of Zeus, London, 2016.)

2 replies »

  1. Phew. Fantastic piece, and so much work and info to be digested, particularly as I’m not in good shape at the moment. But absolutely fascinating with so much food for thought.

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