.jpg)
View Professor Ross Taylor's photo gallery
You can order the DVD from the Academy for $15 (including GST and postage)
Professor Ross Taylor was interviewed in 2000 for the Australian Academy of Science's '100 Years of Australian Science' project funded by the National Council for the Centenary of Federation. This project is part of the Interviews with Australian scientists program. By viewing the interviews in this series, or reading the transcripts and extracts, your students can begin to appreciate Australia's contribution to the growth of scientific knowledge.
The following summary of Taylor's career sets the context for the extract chosen for these teachers notes. The extract covers his study leave at Houston where, as one of NASA's principal investigators, he worked on the geochemical composition of rock samples brought back from the Moon by the various Apollo missions. Use the focus questions that accompany the extract to promote discussion among your students.
Ross Taylor was born in Ashburton, New Zealand in 1925. He was educated at Wakanui Primary School and Ashburton High School. In 1948 he received a BSc from the University of New Zealand and went on to receive a MSc Hons in 1951.
Taylor studied geochemistry at Indiana University, receiving a PhD in 1954. From there he went to Oxford University where he taught and worked with Louis Ahrens, setting up a spectrograph laboratory.
In 1958, Taylor took up an appointment as senior lecturer in geochemistry at the University of Cape Town, South Africa where he did his first work on tektites. In 1961, he moved to the Australian National University as senior fellow in geophysics. In 1962 he was appointed as a professorial fellow in the Research School of Earth Sciences, also at the Australian National University. During this time he continued his work on tektites, developing sample analysis that used mass spectrography. Taylor also used spectrographic analysis to develop a model (the 'andesite model') to explain the growth of the Earth's continental crust.
In 1969 and 1970 Taylor was responsible for carrying out initial chemical analyses of lunar samples brought back to Earth by Apollo 11 and 12, and remained a principal investigator for NASA until 1990. Taylor's work with lunar samples led to his interest in the evolution of the Moon. His spectrographic analysis helped to resolve some of the issues associated with conflicting theories that had been put forward to explain both the evolution and the origin of the Moon. More recently, he extended this interest in planetary origins to look at the evolution of the solar system.
Taylor has written several books – Spectrochemical Analysis, Moon Rocks and Minerals: Scientific results of the Apollo 11 and 12 lunar samples, Lunar Science: A post-Apollo view, Planetary Science: A lunar perspective, The Continental Crust: Its composition and evolution, and Solar System Evolution: A new perspective. He has been a council member (1983-86), vice-president (1987-88), and president (1989-1990) of the Meteoritical Society.
Taylor became a Fellow of the Australian Academy of Science in 1978 and a foreign associate of the United States National Academy of Sciences in 1994. He has received numerous awards from scientific organisations including the Goldschmidt Medal (The Geochemical Society, 1993) and the G. K. Gilbert Award (Geological Society of America, 1994). In 1997 Gene Shoemaker named a comet after him – 5670 Rosstaylor.
Interviewer: You remained a consultant for NASA for 20 years, didn’t you?
Yes, as what they called a principal investigator. NASA were very good about issuing lunar samples. They decided very early that the samples would be available to anybody in the world who was sufficiently qualified and applied to work on them. There were two or three hundred principal investigators at various times working on the samples – the distribution of them is almost a reflection of gross national product. NASA have about 800 lbs of samples from Apollo 11, 12, 14, 15, 16 and 17, and a lot of it even now has not been looked at. About half has been put into storage for future work and so on.
There were lots of different samples, but they fall into two basic types. The dark areas on the Moon which make the pictures of the Man in the Moon are lava flows on the surface, mostly filling hollows excavated by large impacts. The white areas are basically a very thick crust, anywhere between 60 and 100 kilometres thick and mostly of feldspar, which is a very unusual composition. This answered another puzzle about the Moon, because on terrestrial analogues people thought these white areas were probably something like granite. We learned that terrestrial analogues were very dangerous: everything in the Moon is a bit different.
I think much of your work on the evolution of the Moon after its creation arose from your study leave at Houston in 1973-74.
Yes. The chemistry of the samples was very complicated. They had lots of strange features relative to terrestrial chemistry: in the lavas there was lots more iron, chromium, titanium and so on, and the highland (white-crust) samples, were mostly feldspar, but in the crust there were also very high concentrations of elements such as thorium and uranium. All this was a great puzzle, because nothing fitted anybody’s previous ideas about how the Moon had been formed. Certainly it wasn’t a primitive object; it was obviously a very fractionated object, unlike what Harold Urey had wanted. So everyone was busy analysing, and producing endless amounts of data – we had thousands of pages of papers dealing with analytical details of the Moon, but no broad overview. The director of the Lunar and Planetary Institute at Houston asked me to try to make some sense of it all, and so I sat down at Houston for a year and tried to work out exactly what all this stuff meant: how the Moon had come to have a thick crust of feldspar, how these lava flows had come into existence and so on. And I produced a model of its geochemical evolution.
We soon realised you had to start with a completely molten Moon, which was a very strange, worrying thing – how did you melt it? Then, having melted it, you went through a crystallisation sequence: you started forming minerals like olivine, which sank to the bottom, and feldspar, which floated to the top. And you did a gigantic differentiation of a fractionation moon, so you finished up with a crust like icebergs of feldspar, floating on a liquid which then slowly crystallised underneath. From that, subsequently, a little bit of radioactive heating in it produced lava which came out and flooded over the top of the white crust, producing the dark markings on the Moon. That’s pretty much the standard model now, but like all these things it survives intense amounts of criticism – from some of my nearest colleagues, actually.
Select activities that are most appropriate for your lesson plan or add your own. You can also encourage students to identify key issues in the preceding extract and devise their own questions or topics for discussion.
© 2024 Australian Academy of Science
