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# Hailing Frequencies Open, Captain''
A message was sent on November 16, 1974 to the globular cluster M 13. Unfortunately, since M 13 is about 25,000 light-years away, we will have to wait about 50,000 years for a reply. Messages have been attached to the Pioneer and Voyager spacecraft, but they will take thousands of years to reach the nearest stars. Our main mode of communication is the inadvertent messages we have been transmitting for several decades now: some of the signal in television and radio broadcasts leaks out to space and rushes outward at the speed of light. It takes many years for the radio and television signals to reach the nearest stars because of the great distances to even the nearest stars. So perhaps radio astronomers on other planets are watching the original broadcasts of Gilligan's Island'' or Three's Company'' and are seriously reconsidering their decision to say hello (message for network legal department: that is a facetious statement and is not to be taken as a serious statement about the quality of your boss' product). We are currently in a major technology switch-over between television/radio broadcasts (over the air to cable) and telephone communication (land-line to cellular) that does affect how much noise and the type of noise we are making.