We keep getting less and less extraordinary the more we look. Whereas at the time of Asimov's or Sagan's writings (a few decades ago, the first exoplanet being

We keep getting less and less extraordinary the more we look. Whereas at the time of Asimov's or Sagan's writings (a few decades ago, the first exoplanet being detected in 1988) we didn't know of a single planet orbiting another sun, nowadays telescopes such as Kepler have pushed the estimate of the number of planets _just_ in the goldilocks zone to several billion inside the milky way. One in five sun-like stars may contain a planet capable of holding water: http://www.latimes.com/science/la-sci-earth-like-planets-20131105-story.html http://www.latimes.com/science/la-sci-earth-like-planets-201... https://en.wikipedia.org/wiki/List_of_potentially_habitable_exoplanets https://en.wikipedia.org/wiki/List_of_potentially_habitable_... https://www.universetoday.com/49605/how-common-are-solar-systems-like-ours/ https://www.universetoday.com/49605/how-common-are-solar-sys...