50 Years Ago

The importance of lunar natural resources for the future of space exploration can scarcely be exaggerated. Lunar resources will not only play an important part in the establishment of a lunar base by providing life support materials and vehicle fuels but will also be an important, and perhaps a limiting, factor in the logistics of interplanetary space exploration. Certainly, only the most cursory exploration of the solar system could be conducted using either existing or planned propulsion systems so long as the rocket vehicles must lift all their fuel from the surface of the Earth. A lunar fuel source, on the other hand, would provide an extremely convenient low-gravity refuelling station in space.

From Nature 4 August 1962

100 Years Ago

A note bearing on the much-debated question of the age of the earth is given in the Proceedings of the Tokyo Mathematico-physical Society by S. Suzuki. The calculation refers to the time taken for the present crust of the earth to solidify. A result is obtained on the supposition that the heat of fusion liberated by the solidification of the crust supplies the heat lost by radiation, and it is further assumed that the effect of the curvature of the earth's surface may be neglected. According to these hypotheses the calculated time varies between 30 and 300 million years, according to the kind of rock (gneiss, basalt, or granite) assumed in the calculations. The difficulty is, of course, our imperfect knowledge of the experimental data on which the conclusions are based.

[Editor's note: Latest estimates give Earth's age as 4.5 billion years.]

From Nature 1 August 1912