The gate to the underworld
For instance, myths all over the world speak of an underworld, or a land of the dead. This place has an entrance, and it lies, according to the 'primitive' myths of peoples everywhere, along the annual path of the Sun where it crosses one branch of the Milky Way. This entrance or gate - called Helgrind in Norse myth - lies between the constellations of Scorpius and Sagittarius, and happens to mark the centre of our galaxy. According to the Roman writer Virgil, the entrance was guarded by scorpion men, although the medieval Italian poet Dante preferred centaurs - that is, a creature that was half-man half-horse: Sagittarius.

The Incas celebrated their rites of the dead at the December solstice, when their constellation of the celestial llama (in the western Scorpius) was rising. Then the entrance was 'open' and they proceeded to feast the ancestors as if they were really present.

The Polynesians regarded the Milky Way as 'the road of the souls as they pass to the spirit world'. The Sumo Indians of Nicaragua recognise 'mother scorpion' in the Milky Way as the ultimate destination of the souls of the dead.

All Hallows Eve
We in the West celebrate the ancient pagan festival of Halloween (All Hallows Eve), and then soberly go to church two days later to celebrate All Souls Day. When the original pagan rites were first performed in Europe, the entrance to the land of the dead rose at this time of year.

Meanwhile, throughout Central and South America, native Indians spend All Hallows Eve in the graveyards, having brought food to feast their dead loved ones who will return at dawn.

A shared cosmological vision
The list is as endless as the point is clear. Somewhere in our past, people the world over were on the same page. What's going on here?

There are those who argue that such ideas are 'obvious' or the product of a 'universal unconscious'. But why did all these ancient peoples choose this particular place in the sky? At some point in our distant past, did the vast majority of people on our planet participate in a shared cosmological vision of the human adventure?

The technical language embedded in Inca myth contains many idiosyncratic images and conceits shared by ancient civilisations on five continents. This suggests a level of contact among ancient peoples the world over at odds with the official, academic view.

Carved into a cliff overlooking the Sacred Valley of the Incas is a gigantic (45metre/150 feet) face of a bearded man wearing the cap of a priest-astronomer. Is this the mythical bearded god Wiraqocha, said to have founded agricultural civilisation and brought the knowledge of the stars to the Andes two millennia earlier? Who is he and what does his presence here - among a people who don't have beards - tell us about how we understand the past?