Letters to the Editor

19322

By Science News

- More than 2 years ago

Your article neglects the most difficult problem associated with sending a probe to the vicinity of Earth’s core: sending the information back. Even a few feet of earth will stop conventional radio waves. Extra-low-frequency transmissions would do the job, but a transmission could take years.

Augusto Soux
San Diego, Calif.

David J. Stevenson of the California Institute of Technology in Pasadena envisions a probe that sends data via encoded vibrations at low frequencies.