QUESTION:
Do you know if there is any noise on Mars?  

ANSWER from Jim Murphy on June 4, 1997:
This is really quite an interesting question. Yes, there is sound on Mars. 
Any gas, can (I think) transmit sound (a sound wave), and since Mars has an
atmosphere, which is carbon dioxide gas, sound will travel there if
produced.

Now, there are not any car horns, or loudly played boom boxes, or planes
flying overhead on Mars, so there are not the typical noise makers present
on Mars which we are accustomed to here on Earth. However, the wind blowing
along the surface would likely produce sounds as it flows around objects
(rocks, sand dunes) and lifts small dust particles from the ground which
might generate a sound when they hit back onto the surface.

The Viking landers, in the late 1970's, landed on mars but they did not
carry any microphones (electronic ears) with which to listen for sounds.
The Mars Pathfinder lander, which will land on Mars on July 4th, one month 
today (!!!), also does not have onboard any instruments which can listen for
sound.  I think it would be a terrific idea for a future spacecraft to
carry a microphone and listen for martian sounds. It would also be
interesting to have a radio speaker onboard and some nusic, or a speech,
or something else on a CD onboard. Then, the music or whatever could
be 'played' and 'heard' on Mars, and we could compare what it sounds like
compared to playing and listening to the same here on Earth.

One additional feature that a speaker-microphone could offer is determining
the air temperature. Since the speed of sound is dependent upon the air
temperature (actually, the square root of the temperature in Kelvin units),
if we could time how long it took for the sound to travel from the speaker
to the microphone, we would know the air temperature.

On July 4th, when Mars Pathfinder lands, there will be sounds at the
landing site (again, we won't hear them).  These will include the parachute
which will slow the spacecraft as it falls through the atmosphere, rockets
which will do the same, the inflation of airbags around the spacecraft
before it hits the ground, the balloon-shrouded spacecraft bouncing and
rolling, the balloon deflating, the spacecraft 'petals' opening up, the
camera popping up like a Jack-in-the box (without the ..dant-dantdant-dant-
dantdantdant dant ... music). I'd sure like to be there to hear all this,
and see it too!!
Have a fun summer!!
   Jim Murphy

ANSWER from Donna Shirley on July 21, 1997:
Mars atmosphere is so thin that there will probably be no sounds, and there
is little scientific value to listening.  There is supposed to be a
microphone on the Mars Surveyor 98 lander.