Thanks Red Badger. Probably the sound of civilizations being destroyed by A) natural events such as supernovae and impacts, B) themselves, or C) other civilizations. By the time there's a significant permanent human presence on Mars -- in the area of a century from now -- the first superluminal probe will be launched to Alpha Centauri. Extra to String Theory, APoD.
stop the foolishness ... what is past is past and you and I know it but here we find another Holiday Inn Express? ... LOL