Venus de Seismo: New Orbiter Begins to Listen for Venusquakes
Scientific American August 2006 (also at www.sciam.com)
Our planet earth is not the only planet to have earthquakes, Venus has them too, but surprisingly enough they are called Venusquakes. Scientists believe that Venus was capable of sustaining life around 500 million years ago, but volcanism could have changed the surface and made it impossible for life to survive. If the interior structure of Venus could be understood, scientists believe they could begin to comprehend what happened to the planet Venus and why it is now inhabitable. Measuring seismic activity from Venusquakes just may be the answer by discovering what is beneath the surface.
Venusquakes cause tremors that in turn, like earthquakes, cause low-frequency sound waves. Since Venus has a much denser atmosphere, it can pick up a larger amount of the seismic energy created from these tremors. The sound is amplified because Venus’ atmosphere is farther from its surface than Earth’s. The amplification occurs because the sound spreads out longer into the thinner air and deposits energy in the upper atmosphere. This amplification will cause the pressure and temperature to rise and a spectrometer can detect this change. In Physics amplification is the process of increasing the magnitude of a variable quantity without altering any other quality. Because of the amplification the spectrometer can detect changes on the surface and send the information back to Earth, it would not be able to do otherwise. A spectrometer is a device used in both physics and chemistry that can measure wavelengths. Scientists are hopeful that this expedition will lead to some new and exciting research about Venus and may even help in the understanding of the Earth’s core.