Lander to listen for the sounds of Mars

The Mars Microphone

November 1, 1999
Web posted at: 7:25 p.m. EST (0025 GMT)

(CNN) -- An idea first proposed by the late Carl Sagan will finally come to fruition in December, when NASA and the Planetary Society conduct an unusual experiment aboard the Mars Polar Lander.

The primary mission of the Lander is to study the soil, weather and atmospheric dust of Mars, as well as to take photographs of the southern polar region. But the compact spacecraft will also carry a tiny microphone, like those used in hearing aids, that will give scientists and laypeople their first chance to hear what the surface of Earth's neighbor sounds like.

	MESSAGE BOARD
Destination Mars
	AUDIO
The way things sound on Mars The following sound samples were recorded in vacuum chamber simulating Mars atmospheric conditions. (Sound files courtesy University of California, Berkeley, and the Planetary Society) Coughing 54K/7 sec. AIFF or WAV sound
Earthquake 74K/9 sec. AIFF or WAV sound
Robotic arm 84K/10 sec. AIFF or WAV sound
2001 Theme 120K/15 sec. AIFF or WAV sound
	VIDEO
The following series of animations were created for NASA by Engineered Multimedia. Separation of solar array and microprobes 4 MB / 14 sec. / 320x240 QuickTime movie Please enable Javascript
Lander descends by parachute 9.5MB / 28 sec. / 320x240 QuickTime movie
Please enable Javascript
Lander touchdown 13.4MB / 40 sec. / 320x240 QuickTime movie
Please enable Javascript
Mars Polar Lander animation Windows Media 28K 80K

The microphone will listen for 10 second intervals, and record occasional frequency spectrum information. Scientists will use the latter information to determine the tonal structure of the sound.

The sound files will be posted for downloading on CNN.com, NASA, and other Web sites.

Sound on the surface of Mars is expected to be similar to that on Earth, except much fainter because there is less atmosphere to push around, according to the project's developers.

The Lander's mic will compensate with amplifier circuits, and thus be able to pick up sounds fainter than those that could be detected by the human ear.

Among the sounds it might hear:

• Those made by the Lander's own motors, robotic arm and other mechanical parts.
• Sand blown against the Lander and the surrounding terrain.
• Wind gusts
• Sounds from electrical discharges in the dust clouds.
• Other, unexpected sounds.

NASA officials say experience has shown that when a new instrument is developed and flown in space, it usually yields surprises about extraterrestrial environments.

The matchbox-sized device will piggyback on Russian instrument called a lidar, which will study the distribution of dust in the Martian atmosphere.

The microphone is funded solely by the Planetary Society, a worldwide nonprofit organization devoted to encouraging space exploration and the search for extraterrestrial life.

It is first instrument paid for by a membership organization to fly to another world, according to the Society.

Factoid

Microphones in space exploration are not new, according to the Planetary Society. Other interplanetary microphone suggestions have been made over the last two decades and two were actually implemented:

• Russian scientists sent a microphone to Venus in the 1980s and heard electrical discharges, although the results were not reported in the published literature.
• The Apollo missions used microphones on the moon -- for the astronauts to communicate with Earth.