Mathematical SETI

Part of the series Springer Praxis Books pp 361-375


Belt of focal spheres between 550 and 17,000 AU

  • Claudio MacconeAffiliated withInternational Academy of Astronautics and Istituto Nazionale di Astrofisica Email author 

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The gravitational lens of the Sun has a drawback: the solar corona. This is discussed at length in Chapter 8 of [19] and exemplified by Figure 14.1. Electrons in the corona make electromagnetic waves “diverge” and this “pushes the focus out” to distances greater than 550 AU. For instance, at the CMB peak frequency of 160 GHz, the true focus lies at 763 AU. Thus, it would be safer to position the FOCAL spacecraft at 1,000 AU.