Moon dust, age of Moon, and creationism
I recently had a discussion with a "young Earth" believer in Biblical cre-
ation. He raised an argument claiming that the Moon could not be as old as
scientists claim because there is not as much dust (cosmic dust?) accumulat-
ed on its surface as would be expected from its rate of deposition. I had
never heard this argument before, and I am not sure where to go to research
the problem. Has anyone dealt with question before, and do you know of any
references that address this question?
I am not familiar with this argument. I think any good general astronomy
textbook would be a good place to start looking for references. I believe
that some of the rocks returned by the Apollo missions were quite old, but
other were formed more recently. Apparently some parts of the lunar surface
were flooded by molten lava 1-2 billion years after its formation. That
would certainly destroy wipe out any dust layer. In addition, I believe
that the origin of the Moon is still unknown. Some people believe it was
formed in unison with the Earth; others believe it was a separate body which
was captured by the Earth.
Up-date: July 2008
This is a common, but outdated and incorrect claim. It was based on a bad
calculation in 1960 by H. Patterson in a Scientific American article which was
debunked first in 1984. Patterson made an incorrect assumption about nickel
content in meteors (assuming that all nickel in airborne terrestrial dust was
meteoric, when it was actually largely terrestrial), and creationists apply this
number to the Moon, where, in fact, the meteoric dust influx rate is even less
due to the lesser gravity. Since the Apollo program, instruments on the Moon
(and many other methods of confirmation) indicate that the lunar influx rate is
on the order of a thousand times smaller than Patterson claimed.
Further, although the Apollo lander’s disked feet only sank in a few inches, on
Youtube you can see a video of an astronaut jamming a 1 meter rod into the lunar
soil, indicating more compacted dust than normally is seen as astronauts kick up
the top few inches.
Lastly, moon rocks retrieved by Apollo astronauts and photos of lunar mountains
show clear evidence of erosion (moonrocks are jagged under the soil level, and
eroded where exposed). Evidence indicates this occurred due to micrometeroid
strikes, and at the glacial pace that these occur, this couldn’t have happened in
thousands of years, but many millions or billions.
Interestingly, many creationists (e.g., creationontheweb.com), are abandoning books
making these claims, saying about one book: "Despite its good intentions, it seemed
to be focusing heavily on material that was incorrect, outdated by many decades,
speculative, poorly documented, and usually not peer-reviewed by the creationist
For more information, consult the references below.
Dalrymple, G.B. (1984) How old is the Earth? A reply to "scientific" creationism.
Proceedings, 63rd Annual Meeting of the Pacific devision, American Association for
the Advancement of Science, 1(2) 66-131.
Dohnanyi, J.S. (1972) Interplanetary objects in review: statistics of their masses
and dynamics. Icarus, 17: 1-48.
Hughes, D.W. (1975) Cosmic dust influx to the Earth. Space Research XV: 531-539.
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Update: June 2012