The atmospheric pressure on the surface of Mars is small, amounting to around 0.1 percent of the Earth's sea level pressure. But even at Mars' low pressure, acoustic signals within the frequency range of the human ear can be detected. And while the atmosphere of Mars is very different from Earth's, consisting mostly of carbon dioxide, there are similarities between these environments that should make the sound data interesting and important. Billions of years ago, when the Martian atmosphere may have been thick and warm, rivers almost certainly flowed over the surface. The thin Martian atmosphere supports a complex variety of clouds, winds and weather patterns.
Cyclones often swirl near the polar caps in late summer and fall.
Like the Earth's poles, the north and south poles of Mars are coated in ice. Each pole also features a permanent cap. For more information on the Mars Polar Lander mission and the microphone, click here . The Planetary Society. All rights reserved.