Fajada Butte, a huge rock formation in the New Mexico desert, where
a ‘sun dagger’ bisects an ancient spiral carving on the summer solstice
Overleaf: Stonehenge in Wiltshire, UK, which also shows its creators
had precise astronomical knowledge of the path of the sun
On a blazing hot day in the summer of 1977, Anna Sofaer found herself at the top of Fajada Butte – a huge rock formation in the New Mexico desert. An enthusiast of prehistoric rock art, Sofaer had volunteered to
help find and record ancient carvings.
In the shadow of a group of rocks she spotted a beautiful
spiral-shaped carving, which stood out because it was
bisected by a vertical sliver of light shining through
a gap in the rocks. The line – now known as the ‘sun
dagger’ – cut right through the centre of the spiral. It
was no coincidence that the sun dagger was visible to
Sofaer at that moment: the time was noon, and the date
was just days before the summer solstice.
Sofaer went on to discover similar references to
the sun’s movement all around in the nearby ruins
of the Chaco culture – an ancient pueblo people who
inhabited the area a millennium ago and left numerous
monuments behind. The orientation, internal layout
and position of their buildings relative to each other
appeared to be designed to create particular effects
with light and shadow.
At the solstice or equinox, the sun would rise and set
dramatically along the walls of important buildings.
In other spots, the sun and moon were framed in
doorways as they rose and set. ‘Many of the major
buildings appear to incorporate interesting views and
experiences of the sun and moon at the extremes and
mid-positions of their cycles,’ Sofaer writes. Their
construction seemed to have been directed by ‘a
Natural light has always been one of the key forces
shaping the spaces that humans create around
themselves. But the structures of the Chaco culture go
beyond that: these are spaces crafted to respond to the
cycles of celestial bodies.
Capturing the motion of the heavens in light and
architecture, Sofaer says, unified the Chacoan people
with each other and with the cosmos, allowing them to
‘transform an arid empty space into a reach of the mind’.
The study of how people of the past observed
and understood celestial movements is known as
archaeoastronomy. One of its key proponents, Anthony
Aveni, writes that ‘the sky is the primary place to seek
order amidst the chaos that surrounds us’.
It has often fallen to architects, like those of the