A SETI Search Using the 300-Meter Diameter Arecibo Radio Telescope

Multiple Choice

A SETI search using the 300-meter diameter Arecibo radio telescope can pick up a 10 million Watt at a distance of 1,000 light-years. If we were to detect a similar signal coming from 10,000 light-years away, how powerful would the alien antenna have to be?

A) 1 billion Watts
B) 10 million Watts
C) 10 billion Watts
D) 100 million Watts