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Messages into space

  1. Jul 23, 2010 #1
    If I wanted to send a radio signal to another star, shouldn’t I have to account for where the star will be when the message arrives?
     
  2. jcsd
  3. Jul 23, 2010 #2

    russ_watters

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    If you send it with a parabolic dish, yes, but if you send it in a way that is not as directional (just an antenna, for example) no.
     
  4. Jul 23, 2010 #3
    just a quck folow up question russ, wouldnt the parabolic dish still not make much of a difference? i mean, the radio waves should still spead out enough thoughout space right? unless one was trying to reach Mars. but Alpha-Centari should just be "There it is. Point and shoot!" right"
     
  5. Jul 24, 2010 #4

    russ_watters

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    Yes, the stars we can see with the naked eye don't move much and it is difficult to get a very tight beam of radio waves. Heck, Mars doesn't even move much in the few minutes it takes for a signal to reach it.
     
  6. Jul 24, 2010 #5
    I was reading up on the first organized message sent into space, the Arecibo Message. It was sent to Messier 13 some 26,000 ly away. I am guessing under this scenario you'd have to account for movement, as the stars can orbit around the galaxy quite a bit in 26,000 years. Or would this message still be broad enough to cover it?
     
  7. Jul 25, 2010 #6
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