Researchers at Imperial College London have just begun a 5-year project to design and build tiny earthquake measuring devices to go to Mars on the 2007 NetLander mission. Unlike the instruments on next year’s European Mars Express/Beagle II mission, the Marsquake sensors will be the first to look deep inside the planet. The internal structure of Mars is a key to understanding some fundamental questions about the planet including whether life ever existed there. The sensors are capable of detecting liquid water reservoirs hidden below the surface, where life could possibly survive on Mars today. The recent discovery by the Mars Odyssey orbiter of large amounts of ice at the poles opens up the possibility of liquid water existing in the warmer conditions underground near the Martian equator. Dr. Tom Pike is designing the heart of the sensor, a two-centimeter square of silicon. “We’re micromachining a near-perfect spring and weight from a single piece of silicon. We’ll be able to detect the weight shuddering in response to a Marsquake from anywhere on the planet,” he said.