Chaldean astronomers. The term Chaldean can refer to a number of ancient civilisations and periods in history, but here is being used to refer to the nomadic people of south-eastern Mesopotamia (modern-day Iraq) that would later found the neo-Babylonian Empire of the 6th century BC. It is thought that astronomers from this civilisation identified the constellations still in use today (diagram being drawn in the sand at bottom left). The clear skies of a desert climate aids such observations. This artwork, by French illustrator Leon Benett (1838-1917), is from Astronomical Myths (1877) by the British geologist John Frederick Blake (1839-1906).