The international scientific community has offered to help confirm any signals. Scientists at radio telescopes in the Netherlands, England and Italy will be listening for a reply, as will scientists at Stanford if they can get time on the Dish, which is booked for another research project. Just as the pitch of a train whistle drops as the locomotive approaches, the characteristics of the space whistle changed. Some of the changes in the space whistle came from the Doppler Effect created through the rotation of Mars and the Earth. I think in reality the chances are small, but we want to make sure.
Space is noisy.
Boding poorly for the mission is the fact that this week the sensitive Dish detected the weaker signal from the surveyor, but not the stronger signal from the lander. But the main problem is the weakness of the signal. A transducer changes one type of energy into another. Using sophisticated software, Linscott and colleagues search among the weak signals for narrow, single tones. What we have are the computers that record the signals from the sky, and more computers to try and analyze those.