a . Glenn R. Morton, Harold S. Slusher, and Richard E. Mandock, “The Age of Lunar Craters,” Creation Research Society Quarterly, Vol. 20, September 1983, pp. 105–108.
The above study drew upon the work of Z. F. Danes, which was described as follows:
The history of a circular crater in a highly viscous medium is derived from the hydrodynamic equations of motion by Z. F. Danes. The variation in shape of the crater in the course of time is expressed as a function of a time constant, T, that involves viscosity and density of the medium, acceleration of gravity, and radius of the crater lip. Correspondence between theoretical crater shapes and the observed ones is good. However the time constant, T, is surprisingly short if commonly accepted viscosity values are used. Geological Survey Professional Paper 550-A (Washington, D.C.: U.S. Government Printing Office, 1966), p. A 127.
Since Danes’ work was published, rocks from the Moon have been returned to Earth and their viscosity has been measured. Their values fall between 1021 to 1022 poises. According to the Geological Survey paper just quoted, “If viscosities of lunar rocks were around 1021 to 1022 poises, the ages of large craters would have to be only 104 to 107 years.”