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Curiosity celebrated it's first birthday by playing, on Mars, Happy Birthday. How was this accomplished, and why would this capability even be included on Mars?

PearsonArtPhoto
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    Relevant video: http://youtu.be/uxVVgBAosqg – User1000547 Aug 07 '13 at 20:59
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    Note, that you can produce music with any kind of electric motor, by driving it with a PWM signal of varying frequency. There are plenty of youtube videos where music is played by floppy disk drives, drills, or other noisy devices containing electric motors. – vsz Aug 08 '13 at 06:17
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    I think the real question is "Did NASA properly pay Warner Music the royalties on the song 'Happy Birthday', and if not, will this be the first interplanetary lawsuit?" – Fake Name Aug 08 '13 at 08:40
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    Alas, Curiosity was able to play it, but not hear it. Like a deaf piano player. – Mark Adler Aug 08 '13 at 17:35
  • Because on the off chance it turns out there are extraterrestrials on Mars, nobody wants to be the person to turn down having put a speaker on Curiosity resulting in an inability to communicate with them. – Thomas Jacobs Feb 10 '16 at 14:45

2 Answers2

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Curiosity does not have speakers. As the OP's linked article states:

This was accomplished using Curiosity's Sample Analysis at Mars (SAM) instrument. It "sang" the song by vibrating at different frequencies.

More information on how this was accomplished is available in this LA Times article:

The Sample Analysis at Mars instrument, or SAM, isn't a musical instrument. It doesn't have keys or strings. It's part of the lab in the rover's belly that analyzes rock samples and helped discover a habitable environment on Mars -- a place where microbes could have hypothetically lived in the past.

But SAM does make noise. In order to shake powdery rock samples so that they settle down, the instrument vibrates at various frequencies, Florence Tan, SAM’s lead electrical engineer, said in a video.

These frequencies can be used as musical notes. And by making SAM shake faster and slower, the team was able to tap out a little birthday tune for the rover on Monday. (They went with Aug. 5 because Curiosity landed around 10:30 p.m. Pacific time on that date.)

coleopterist
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    Woot! I love it when NASA nerds do cool stuff like this for fun. – Shotgun Ninja Aug 07 '13 at 19:50
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    Vibrating at controlled frequencies is the definitive task of a speaker. – aramis Aug 07 '13 at 21:29
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    @aramis: but the SAM instrument does not have the anatomy of, not does it contain, the electromagnetic transducer, hooked to a rigid conical diaphragm, that we know of as an acoustic "speaker". – KeithS Aug 07 '13 at 23:09
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    @KeithS not all speakers do. Some are piezoelectric, some are simply off-set motors with speed determining frequency. And some are spark-gap air exciters. – aramis Aug 08 '13 at 23:13
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    @aramis Gestures at Tesla coil “Surround sound” – Potatoswatter Jan 05 '23 at 15:29
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An article in the Washington post explains:

the rover’s sample analysis unit vibrates at different frequencies to move soil samples. Normally, those vibrations sound remarkably like the noises robots make in Disney’s Wall-E, but when you string them all together, something similar to “Happy Birthday” results.

Chad
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