In the middle of nowhere in particular in the Australian Outback, a rugged massif of sandstone appears above the spinifex grass and mulga bushes. What is that and why is it here?
This puckered mountain ring is of great cultural significance to the Western Arrernte Aboriginal people. One night, in the creation time, the women went dancing across the sky upon the Milky Way. As it was late and her arms were tired, a mother in the group laid down her newborn child to sleep in a wooden baby carrier (a turna). But her baby was restless and was soon awaken by the music. The turna, seated on the edge of the Milky Way, toppled over and the baby fell through the sky, crashing on the Earth.
The baby landed on Earth with a tremendous noise. So large was the crash that it created the circular rock walls of Tnorala. At the end of the dancing, the mother searched fruitlessly in the sky for her baby. The mother and father are still searching for their son, and they can be seen today as the morning and evening stars in the sky.
Geologists and physicists tell another story: One day, about 142 million years ago, a comet or asteroid hit central Australia. The gobsmacking impact of the body, probably 600 m in diameter, produced a crater some 20 km across. Since then, an unimaginable 2000 m, 2 kilometers, of rock and crater sediment have been eroded away by water and the wind. The original crater has all but disappeared, leaving only a circular mountain range 4 km across that is seen today.This curious feature is labeled on the map as Gosse Bluff, named in 1870’s for the explorer and first European to see and climb the nearby--at least by Outback standards--and far more famous outcrop / icon known as Ayres Rock / Uluru.
Only recently has the extraterrestrial origin of Gosse Bluff / Tnorala been recognized by the non-Aborigines. From the ground, the crater’s remains appear as a miniature mountain range. From the air, its ring shape suggests an unusual origin. Far above, viewed from space, contrasting colors of rock still delimit the original crater.
Each of these two stories explains the same landscape, and each is thoroughly embedded in their culture. Aboriginal Dreamtime is the product of a 60,000-year old culture that once thrived in the least hospitable places on Earth. Newtowian physics, deriving from the Principia (1687), has provided a quantitative explanation for scarcely 315 years.Today in Australia, the two cultures, Aborigine and western coexist like these stories, separate and independent.
Surprisingly little written material is available on Aborigine star-lore, and most of that is by non-Aborigines. To Aborigines, the idea of sharing these stories is pointless (if not culturally offensive) in many instances. Still, Dianne Johnson's Night Skies of Aboriginal Australia (1998) is a good source. Crater and impact physics material is much more readily available: Richard Grieve's "Impact Cratering on the Earth" in April 1990 Scientific American and R.B. Banks Towing Icebergs, Falling Dominoes, and Other Adventures in Applied Mathematics (1998). For "do-it-yourself-ers," BASIC programs have been published by John Kennewell in the November 1996 Sky & Telescope. If interested in Australian geology, see R.B. Thompson's A Guide to the Geology and Landforms of Central Australia (1995). For a light-hearted Australian travelogue, I highly recommend Bill Bryson’s latest book, Down Under. There's even a jigsaw puzzle of Gosse Bluff available. G'day mate!
Moondark is written by Doug Miller and published on the web, in the Delmarva Star Gazers'Star Gazer News and in the Delaware Astronomical Society's FOCUS. Please address comments and suggestions to dmiller@udel.edu. This document was last revised on 25 June '00. All text and images copyright © 2000 Douglas C. Miller, All Rights Reserved. This material may not be reproduced in any form without prior permission.