All quiet on Mars

PLANS to send a microphone to Mars on the French space agency’s Netlander
mission in 2007 may be in vain. Scientists had hoped to listen for earthquakes
and Martian storms. But James Chambers from the University of Mississippi has
calculated that sound on Mars will travel a mere 0.2 per cent of the distance it
travels on Earth because the air pressure is so low. The problem is made worse,
he says, because carbon dioxide, the main gas on Mars, absorbs sound very
efficiently at the frequencies the mike is designed to pick up. Microphone
designer Greg Delory from the…