Goddard Space Flight Center, Greenbelt, Maryland 20771 ENGINEERING COLLOQUIUM Monday, April 4, 2005 / 3:30 PM, Building 3 Auditorium Dana Mackenzie "The Big Splat, or How Our Moon Came to Be"
ABSTRACT --
When the Apollo astronauts went to the Moon from 1969 to 1972, one of their
objectives was to discover how the Moon was created, and
in particular to decide among three principal theories (the fission
theory, the capture theory, and the co-accretion theory). What no one
expected was that the Moon rocks would point towards a fourth answer -- none
of the above! In the lecture, Dr. Mackenzie will discuss the history of the theories of
the Moon's origins, the ways in which all three of the pre-Apollo theories
failed to pass physical tests, and how a fourth theory -- the giant impact
theory -- has superseded them. The giant impact theory, in which the Moon
was formed in the aftermath of a collision between Earth and a Mars-sized
planet named Theia, fits in very well with our current understanding of the
dynamics of the early solar system, which was a much more chaotic place than
the theorists of previous generations realized.
At the end of the lecture, Dr. Mackenzie will talk about our "unfinished business" on the
Moon, which could be on the agenda for further manned exploration as part of
the Moon, Mars and Beyond initiative.
SPEAKER -- Dana Mackenzie is a science writer based in Santa Cruz, California. He received a doctorate in mathematics from Princeton University, and taught for thirteen years at Duke University and Kenyon College before heeding a friend's advice to "think about what you wanted to do as a child, and try to make that happen." That was easy -- as a child, he always wanted to be a writer. After learning the ropes of journalism in the Science Communication Program at the University of California at Santa Cruz, he has been a free-lance writer for nearly eight years. His articles have appeared in Science, New Scientist, Discover, and Smithsonian. "The Big Splat, or How Our Moon Came to Be," published by John Wiley & Sons, is his first book. Colloquium Committee Sponsor: Jim Heaney, Swales Aerospace, 301-902-4531 Next Week: "The Hydrogen Economy: Challenges and Opportunities", George Crabtree, Argonne National Laboratory Engineering Colloquium home page: http://ecolloq.gsfc.nasa.gov |