On a autumn evening, anywhere in Australia, find a dark location, well away from street-lights, and look in the South-East for a great dark shape in the sky, with a black head (the Coalsack, next to the Southern Cross), and dark legs trailing our along the Milky Way to Scorpius. This is the great emu in the sky, the subject of songs and stories in many parts of Australia. Just North of Sydney, in the Ku-ring-gai National Park, are extensive rock engravings of the Guringai people who used to live there, including representations of the creator-hero Daramulan and his emu-wife. On autumn evenings, the emu in the sky stands directly over her portrait, just at the time when it's time to gather emu eggs. Is that why the Guringai people carved her picture just there, in just that direction? Sadly, the people who could have told us have long since disappeared.