Even the nearest stars are so distant that a single diffraction limited telescope capable of imaging Earth-size
Question:
Even the nearest stars are so distant that a single diffraction limited telescope capable of imaging Earth-size planets orbiting them would be hopelessly large (see Problem 45). Astronomers get around this limitation using interferometry to combine data from several telescopes, producing an instrument that acts like a single telescope with aperture equal to the distance between the individual telescopes (Fig. ?32.30). The technological challenge is to combine the signals with their relative phase intact; for this reason, interferometry has been used successfully for decades in radio astronomy but only recently with optical telescopes.
Data From Problem 45
NASA asks you to assess the feasibility of a single-mirror spacebased optical telescope that could resolve an Earth-size planet 5 light-years away. What do you conclude?
?
If a point source is located directly above a two-telescope interferometer, on the perpendicular bisector of the line joining the telescopes (source 1 in Fig. 32.30), electromagnetic waves reaching the two will be?a. in phase.?b. out of phase by 45?.?c. out of phase by 90?.?d. you can?t tell without further information
Step by Step Answer:
The correct answer is c Out of phase by 90 The relative phase between two wave...View the full answer
