Approximately how soon might we expect an immediate response from a civilization that received the signal we sent to the globular cluster M13 (25,000 light-years away) in 1974?
A) 100,000 years
B) 25,000 years
C) 12,500 years
D) 50,000 years

Question

Quizplus · Accepted Answer

The signal would take 25,000 years to reach M13, and if a civilization there immediately responded, their reply would take another 25,000 years to return to us, totaling 50,000 years.

Approximately How Soon Might We Expect an Immediate Response from a Civilization