Do you hate your neighbor's blaring radio? Is the dog next door keeping you awake at night? If you're looking for the ultimate quiet neighborhood you can try downtown Mars. Researchers say the cold, thin air on the red planet does not carry sound waves very far. Using a model simulating the Martian atmosphere, they said even a lawnmower's annoying mechanical roar can only be heard within a hundred meters or so.

All kinds of sounds travel the same way - waves of pressure generated by colliding molecules move through air, water or solid objects. The denser the object, the farther sound waves go. In fact, hoofbeats travel faster through the ground than the air. When moving through air, molecules have to travel greater distances to bump to each other and lose energy faster. This is the the principle behind the ear-to-the-ground technique used by Native Americans to detect approaching or departing calvaries. Because the Martian atmosphere is only 0.7% (and mostly CO2) as dense as Earth is, sound waves fade more quickly.

Based on the computer model of how sound moves on Mars developed by Amanda Hanford and Lyle Long of Pennsylvania State University, noise that would travel several kilometers on Earth would die after a few tens of meters on Mars. Henry Bass, a University of Mississippi physicist said, based on these findings, people on Mars need devices that can work with the lower frequencies transmitted by the Martian atmosphere for long distance communication. You mean like cell phones