The Sounds Of Venus? Options

[Guest_BruceMoomaw_*]

In its latest print issue, the Planetary Society reported the following, in connection with GROZA (the attempted thunder-detecting microphone on Veneras 13 and 14):

"The Planetary Society recently contacted GROZA's principal investigator Leonid Ksanformaliti, an old friend of the society from the Space Research Institute in Moscow, and asked if these data had ever been converted to sound. They had not. At the Society's request, he generously pulled out the old data and has begun the process of converting the data to sound. These Venusian sounds will soon appear on the Planetary Society's website."

Well, Jeffrey Bell -- AKA Mr. Sunshine -- now reports to me:

"Argh! Unpleasant memory blast from former life! Resist powerful urge to smash expensive flat monitor!

"I had some dealings with Comrade Ksanfomaliti back at the time of the PHOBOS fiasco in 1988. I wouldn't trust him to clean my air conditioner. He was one of those all-purpose scientists who made an instrument for every mission, always a different instrument in a different field, and always a disaster. He seemed to have some powerful political influence that kept him in the program. Of course the PS
would latch onto this guy, with their unerring nose for incompetence."
_____________________________________

Well, that's OK -- if no interesting Venusian sounds turn up on those tapes,
the Russians can always fake some. (After all, their "scientific space
program" now consists entirely of ways to continue sponging off NASA's Space
Station budget.) Be on the lookout for Venusian "thunderclaps" that sound
suspiciously like someone shaking a large sheet of tin.

[Guest_Richard Trigaux_*]

Besides their scientifical interest, sounds carry still much more emotional impact than images or informations. So I think it would be very interesting to hear these sounds, if there are some.

But I remember the famous "Titan sounds" from Huygens, which were not sounds, but just sonograms converted to sound. Are these venusian sounds the same?

Anyway remember that venusian clouds are very high, 60kms, even higher than Titan clouds. When on Earth Lightning sound is seldom heard further than 30kms.

I heard once that Oppy and Spirid had microphones, or at least that such a device was debated during design. Is it true? (Dream not) And if true, did they recorded something? We could perhaps hear whirlwinds. Or meteorite booms. O something unheard before.

To HEAR something from another world!!

[edstrick]

My recollection from published papers in translated Soviet Journals was that acoustic signal amplitude was recorded at frequent intervals during descent and during brief spots if descent-science instrumentation that interrupted surface science transmission. If I recall correctly, more or less constant high amplitude noise was present during descent and signals were more or less below detectable levels on the surface. I don't recall if any landed hardware mechanical noises were reported.

I think what was transmitted was just the total signal strength during a short period, not the waveform at all. The most you could get out of such data would be very limited. I don't think the Huygens data is much better. I'd have to dig out the atmosphere structure description, but I don't think they recorded any real spectrum of the acoustic noise, maybe coarsely sampled amplitude at (perhaps 4 or something) discrete frequencies.

I'm very underwhelmed by the "Sounds of Titan" recordings that were synthesized and released.

[Guest_Richard Trigaux_*]

I did not found them back in the ESA site, but the Titan "sound" records were sonograms, giving coarse spectra of frequency, sampled or averaged every 2 seconds, and tremendously compressed to only some 50 bytes per second. To "retranscript" this in sounds requires a white noise source and an equalizer, but in this way we could not distinguist a car noise from an opera. I did not expected to hear birds songs on Titan, but I would have enjoyed very much to hear at least wind whirling around the probe during descent, and a splash noise at landing, as human ear can immediatelly distinguish if the landing is into sand, stones or mud. Afer there was no sound, but we could have got the luck to hear wind, waves or liquid streaming. Or perhaps thunder, as expected.

Why such a compression rate? Because the energy in Huygens (necessary to have large bandwidth) was very restricted. It was probably the same with the russian landers on Venus.

This arises the question of energy in exploring far planets. No sun, long voyages, made nuclear fission or radioisotope cells the only known solution. But to speak frankly I do not like this, we already polluted our planet with this, so we could at least avoid to contaminate all the solar system. The only prospective solution would be small fusion cells.

If we consider the success of Spirit and Opportunity, we note that it is largely based on the availability of several radio relays in orbit, with plenty of solar energy. (and cameras to inspect the further path on the ground). Similarly exploring Titan would first require a large telecommunication satellite in orbit with kilowatts of power, a supercomputer and a life expectancy of 100 years.

[edstrick]

Things that COULD get turned into real sound:
Viking 2's seismometer could operate briefly in full waveform recording mode. There was also a very compressed mode where it recorded peak amplitude and number of zero-point crossings of the wave in each interval, and a third supercompressed form.

The full sampling rate data could be turned into wind and mechanical activity noise, frequency shifted upwards into the human hearing range. 3-channel stereo, too!

Much the same could be done with the Apollo seismometer data: 3 Long-period axes and 1 vertical short period channel.

Also, the Apollo 14 and 17 Lunar surface experiments, where a geophone array was set out and explosive charges were set off at varying ranges.

You could also "hear' the Surveyor lunar landings: Each leg had strain-guages with a very high readout rate to catch the leg-surface interaction during touchdown. THUMP........ Thump... thump-ump-ump..jiggle-jiggle..... (They rebounded a few inches at the first and second toucheowns)

[djellison]

I suppose the accelerometers on Pathfinder and MER could be used to so SOMETHING like that - use some white noise and use accel as amplitude

Doug

[Guest_Richard Trigaux_*]

I suppose the accelerometers on Pathfinder and MER could be used to so SOMETHING like that - use some white noise and use accel as amplitude
Doug

We could that way record the "noise" or MER's movements. Perhaps the noise of wheels grasping on rocks. But are the accelerometres sensitive enough to record seismic activity, or even wind activity? Enough bandwidth?

A true seismograph is not a small device, so they did not placed one on the MERs. Anyway seisms may be rare on Mars. But perhaps they will try what was done for the Moon: place several seismometres, and send a cruise stage slamming on the ground, to have an artificial seism.

[edstrick]

Seismometers are pretty useless on rovers. Up in the air <sensative to wind>, not mechanically well coupled to the ground <signals are modified as they travel through the suspension system>, at a location that keeps changing <much interpretation REQUIRES the local propagation of signals doesn't change>, and is utterly irrelevant to rover science.

Always remember, when we grumble "why couldn't the rover carry..."... (which I do), the rovers are the biggest and most crammed with instruments rovers that could fit on the Delta launch vehicles that launched'm.

[Guest_BruceMoomaw_*]

The thing to do with seismometers is to put 'em on a network of multiple stationary landers simultaneously -- period. You can't even do all that much even with one on a stationary single lander; on rovers they're hopeless. And I agree with Doug Ellison that this -- rather than trying for that ExoMars biorover which would supposedly be both much lighter and more scientifically capable than MSL -- is what the ESA should be doing at Mars; it would be very easy for them to take over the Netlander program from the French.

We also need such a network for meteorology, which appears growingly important to provide preparatory safety data for future landers -- and if subsurface radar sounding from orbit proves impractical at Mars, such network landers, using seismic and/or magnetotelluric sensors, will also be the only workable way to look for subsurface liquid water.

[Guest_Richard Trigaux_*]

... such network landers, using seismic and/or magnetotelluric sensors, will also be the only workable way to look for subsurface liquid water.

... and to the inner structure of the planet.

The structure of Earth is understood, with its "liquid" inside, different layers, plate tectonics, etc.
The structure and history of the Moon is understood - a former liquid inside led to the gigantic lava flows forming the "seas" billions yeras ago, and since everything is frozen.
Venus may have a similar structure than Earth, except that, for some reason, there is no plate tectonics.

But Mars? It rather ressembles the Moon, with a former "liquid" inner layer. But, as the study of magnetic field showed, there is no "liquid" inside left today. However there are volcanoes. And still active, after recent datations, even if there is an eruption every 50 million years. But, if there is no inner "liquid" core as on Earth, how the magmas are generated?

Recent studies (see this site, where there are several interesting pages) there may be two sources for martian magmas. We have no idea of the inner martian structure, it may even be assymetric.

So a seismometre network is worth trying, to the condition of doing things correctly, with enough network.

[dvandorn]

A seismometer network is an absolute requirement to understanding Mars' inner structure. The problem with the type of emplacement Viking attempted was that the instrument was mounted to the lander, not in actual, physical contact with the ground.

What with the current state of the art in remote manipulation, do y'all think it would be worth the extra weight to deploy seismometers by unshipping them from the landers and actually emplacing them onto/into the soil? I'm guessing it would require some kind of deployment arm -- but depending on the rest of the science package on a lander (even a netlander-scoped device), such an arm would be useful for other tasks, as well.

-the other Doug

[edstrick]

The way to deploy a seismometer network is with penetrators, like the two that will be on the Japanese Lunar-A mission, if it every flys.

The Mars-96 mission carried 2 penetrators and 2 hard landers, if I recall correctly. It was total lunacy to send the half-assed Beagle-2 (which could have been a good mission with decent management, quality control and funding) instead of a Mars-96 design penetrator on hard lander on Mars Express.

No..... not lunacy... that'd be a lunar mission. Mars Madness?


Penetrators give maximum coupling with the crust and minimal wind interference.

[Guest_Richard Trigaux_*]

About sounds of Venus, and generally sounds from outer space, I recomment this link: Sounds of pulsars and other pages on the same site, magnetosphere sounds, satellite sounds, etc. Some are really astounding, other are moving, others are strange or beautiful... Especially pulsar sounds are really unearthy, and, surprinsingly, fast pulsars create a kind of everplaying symphony...



In a general way we should not hide behind rational or utilitary motives when doing science and space exploration. It is the full play of our consciousness exploring the universe. I have no use of Mars, but I really want to know what is there on Mars. The sound of a whirlwind is worth the price to send a microphone.




A strange experiment would be to convert seismic waves into sound. Forinstance, we take the recordings of two seismometres on the Moon, when they sent the cruise stage slamming on the ground, and we send these sounds in a stereo headphone. Given the ability of the human ear to analyse sounds, there may be science data do extract for this, but especially we should hear the Moon resounding like a cymbal under the shock!

[Bob Shaw]

What with the current state of the art in remote manipulation, do y'all think it would be worth the extra weight to deploy seismometers by unshipping them from the landers and actually emplacing them onto/into the soil?  I'm guessing it would require some kind of deployment arm -- but depending on the rest of the science package on a lander (even a netlander-scoped device), such an arm would be useful for other tasks, as well.

-the other Doug

Well, there are presently two nice, stable platforms sitting on the surface of Mars, doing not a lot. It's not beyond the bounds of engineering to attach a hard-lander style seismometer package to a lander module - even a SkyCrane - and implant the things with a small solid-rocket charge (once Mr Rover has cleared the site!).

Of course, it all weighs...

[djellison]

Of course, it all weighs...

Think something could be done with a DS2 type mass/volume budget?

Doug