According to some Creationists, the earth gets millions of tons of dust per year from outer space. Therefore, the moon also gets a fair bit. If the moon is five billion years old, then it should be covered in 50 or 100 feet of dust. It isn't. Therefore, the moon must be much younger than scientists say.
Notice that this is not a claim based on the Bible. The specific number of tons per year is quoted from the scientific literature.
The infall of dust is one hundred times less than these Creationists say it is. This has been known since about 1963. The argument has been kept alive by not quoting from scientific articles written after 1960.
In the 1950's, Hans Pettersson went to the top of a tall mountain, ran some air through a filter, and then measured the dust in the filter. He concluded that at the very most, 15 million tons of dust was arriving yearly from outer space. He guessed that not all of his dust was from space, so he thought that 5 million tons was a more likely figure. He wrote an article about this for the February 1960 Scientific American.
1960 was also the year of President Kennedy's promise to put a man on the moon. NASA got a lot of money, and started up a lot of committees. One of the committees pointed out that they should make a measurement IN SPACE of space dust. This was done, and McCracken and Dublin announced (at the 1963 Lunar Surface Layer conference) that the earth gets a piddling 18,000 to 25,000 tons per year. At the 1965 conference, the photographs taken by the Ranger probe were shown, and it was agreed that the moon didn't look dusty. In May 1966, Surveyor I landed on the moon, and the issue was settled. The engineers designing the Lunar Lander were told to give it short legs. A landing spot was chosen in the rocky uplands, just in case lowlands and valleys had pools of dust.
In 1974, Henry Morris started the Moon Dust argument. In his book he said, on page 151-152:
The best measurements have been made by Hans Pettersson, who obtained the figure of 14 million tons per year.
(Before the moon landings, there was considerable fear that the men would sink into the dust when they arrived on the moon, but no comment has apparently ever been made by the authorities as to why it wasn't there as anticipated).
There are two inaccuracies in the first sentence, and one in the second sentence.
In the second (1985) edition of the book, Morris produced a completely astonishing number, 200 million tons a year, and referred readers to "G.S. Hawkins, Ed., Meteor Orbits and Dust, published by NASA, 1976". This document (actually published in 1967) does not contain that number. Apparently Morris had an unnamed "creationist physicist" calculate the number, and he calculated it wrong.
Richard Bliss of the ICR has since produced another number, a million tons, this time giving a reference to "COMITE Speciale De I'annee Geophysique International, Moscow, August 1985". That sounds pretty recent, until you realize that the International Geophysical Year was held in 1957-1958. The committee report was published in 1958, not 1985.
In 1989, Walter Brown produced two references (to Stuart R. Taylor and to David W. Hughes) and from them he calculated 2,000 feet of moon dust. This is a very strange number, since Pettersson's measurement gave 100 feet as an upper bound. Schadewald tried to repeat Brown's calculation, and came up with one inch of dust.
Creationists Snelling and Rush have documented the situation, and agree that the moon's dust is not proof of a young earth. However, many other Creationists have published the Moon Dust claim, and some still do. It's on the Web today.
NASA and the USSR have not ignored this technical issue in the decades since landing on the moon. It is, after all, relevant to the health of satellites and space stations. (In 1998, more than 600 satellites were orbiting the Earth.) There have been theoretical calculations. There have been measurements done by shining lasers into space. There have been measurements based on the chemistry of deep sea sediments. And NASA put up a satellite, the Long Duration Exposure Facility, LDEF. It went up in 1984, and they retrieved it in 1990 to study the amount of damage from years of tiny impacts. LDEF gave us a figure of 40,000 tons per year - a long way from millions.
Once again, the Moon Dust argument is not based on the Bible. It is a purely scientific argument, based on calculation and on the evidence in the publicly available scientific literature. (NASA is a civilian agency, and its studies are available in libraries.) The current scientific estimate is that the moon gets about an inch of dust per billion years.
For more information:
The Moon Dust FAQ (has a really good reading list)
The Age of the Earth has a chapter describing the Moon's surface, and how it has been dated.
Old Earth Arguments FAQ
Footprints in the Dust: The Lunar Surface and Creationism, Shore, Steven N., Creation/Evolution Issue XIV (Fall 1984), pp.32-35 National Center for Science Education
Walter Brown and the Moon Dust, Schadewald, Robert J., NCSE Reports Vol.10, No.3 (May-June 1990), p.16
Moon Dust and the Age of the Solar System, Andrew A. Snelling and David E. Rush, Creation Ex Nihilo Technical Journal, vol. 7 #11, 1993, pp. 2-42
The Soviet-American Conference on Cosmochemistry of the Moon and Planets, 1977, NASA SP-370, (Vol. 2), pp. 571-664.
Soils of the Past, Rettallack, G. J., Unwin Hyman 1990, ISBN 0-04-551128-4, pp. 295-301.
the LDEF satellite