Grains of carbon based cosmic dust – the stuff of which every person is made – were recognized in the early photographs of nebulae and galaxies by EE Barnard and others. How pervasive are these dusty “Shrouds of the Night” in galaxies external to our Milky Way? It was only in 1994 that the dilemma facing astronomers, as to the existence and amounts of cold and very cold dust grains in galaxies other than our Milky Way, was definitely solved. The temperatures of these grains may be as low as minus 253 degrees Centigrade – possibly even colder. In this lecture, we consider two journeys: one of the enigmatic masks of dust themselves, and the other, of the awesome New View of spiral galaxies when viewed behind their masks of dust. We present the “New View” of the Andromeda Spiral Galaxy, Messier 31, when it is “dust penetrated” using the Spitzer Space Telescope: a discovery which was published in “NATURE”. Glowing rings of fire in M31 literally unravel a radically different understanding of the formation of spiral galaxies such as M31, and why “monolithic collapse” from one gargantuan cloud of gas and dust is ruled out.
David Block, director of the AECI-AVENG Cosmic Dust Laboratory at the University of the Witwatersrand, Johannesburg, South Africa. Elected as a Fellow of the Royal Astronomical Society of London at the remarkable age of nineteen, David Block is held in the highest esteem in international astronomical circles. He has conducted research at some of the world’s greatest universities and observatories in Europe, mainland USA, Hawaii and Australia. He is the only South African astronomer to have had his research featured twice on the front cover of the prestigious scientific journal, Nature.