British scientists started building tiny ‘Marsquake’ sensors on Thursday that will be able to detect underground water supplies and could help in the search for life on the red planet. The 2007 NetLander mission will land four sets of instruments near the Martian equator to examine the planet’s weather and geological structure. The quake sensors will be the first to look deep inside the planet, the team responsible for their construction said. “We will look at how the vibrations from Marsquakes travel through the planet and work out what is going on deep inside,” said Imperial College London researcher Dr. Tom Pike. “If these vibrations hit liquid water under the landing sites, we should see a distinctive signature,” he added. “That is when the search for life on Mars will move underground.”