Mankind’s message to planetary onlookers

It was a birthday to remember set against a backdrop of sweeping, recently harvested fields that were dotted with huge bales of straw.

Blood-red poppies and purple loosestrife grew thickly in the hedgerows. A solitary sparrow hawk circled slowly above in a sky that was an almost cloudless blue.

The birthday picnic was to take place on Windmill Hill, a favourite family destination deep in the Wiltshire countryside, high above the plethora of prehistoric sites around the Avebury complex.