Frank D. Drake, an investigator in the SETI (Search for Extra-Terrestrial Intelligence) program, once said that the large radio telescope in Arecibo, Puerto Rico , “can detect a signal which lays down on the entire surface of the earth a power of only one picowatt.” (a) What is the power that would be received by the Arecibo antenna for such a signal? The antenna diameter is 300 m. (b) What would be the power of an isotropic source at the center of our galaxy that could provide such a signal? The galactic center is 2.2 * 10^4 ly away. A light-year is the distance light travels in one year.

Frank D. Drake, an investigator in the SETI (Search for Extra-Terrestrial Intelligence) program, once said that the large radio telescope in Arecibo, Puerto Rico , “can detect a signal which lays down on the entire surface of the earth a power of only one picowatt.” (a) What is the power that would be received by the Arecibo antenna for such a signal? The antenna diameter is 300 m. (b) What would be the power of an isotropic source at the center of our galaxy that could provide such a signal? The galactic center is 2.2 * 10^4 ly away. A light-year is the distance light travels in one year.

Horizons: Exploring the Universe (MindTap Course List)

14th Edition

ISBN:9781305960961

Author:Michael A. Seeds, Dana Backman

Publisher:Michael A. Seeds, Dana Backman

Chapter17: Mercury, Venus, And Mars

Section: Chapter Questions

Problem 1P: Imagine that a spacecraft has landed on Mercury and is transmitting radio signals to Earth at a...

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