Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 11 September 1970:
Vol. 169. no. 3950, pp. 1071 - 1075
DOI: 10.1126/science.169.3950.1071
Prev | Table of Contents | Next

Articles

Apollo 12 Seismic Signal: Indication of a Deep Layer of Powder

Thomas Gold 1 and Steven Soter 1

1 Center for Radiophysics and Space Research, Cornell University, Ithaca, New York 14850

The seismic signal caused by the Apollo 12 lunar module is interpreted in terms of propagation between source and receiver through a layer of powder in which sound velocity increases with depth. This increase, which is due to compaction, extends over several kilometers and leads to a concentration of seismic waves toward the surface. Computer simulations with the use of ray acoustics and on the assumption of a randomly undulating lunar surface approximate well the observed signal. Seismic amplitudes are greatly enhanced in such a medium compared to solid rock, so that the observed signal requires less power to be transmitted than previously estimated.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Seismic energy transmission in the lunar surface zone determined from signals generated by movement of Lunar Rovers.
Y. NAKAMURA (1976)
Bulletin of the Seismological Society of America 66, 593-606
   Abstract »    PDF »
Extralunar Dust in Apollo Cores?.
D. J. Barber, D. J. Barber, I. Hutcheon, and P. B. Price (1971)
Science 171, 372-374
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)