Free Astronomy Magazine November-December 2021

23 NOVEMBER-DECEMBER 2021 ASTRO PUBLISHING vious capacity as a commercial air- plane test pilot had dramatically stumbled upon a flying saucer and tried to gather evidence of what had happened. Cornered by Straker, Foster agrees to join SHADO, be- coming its second most important figure. Although this episode does not seem to offer particular food for thought, in the first scenes SID signals the approach of flying ob- jects and estimates their speed at SOL 8, a value already mentioned in previous episodes. In the UFO series, SOL stands for “speed of light,” and the number indicates how many times the speed of light the aircraft is traveling. In science fiction that contemplates interstellar travel, exceeding the speed of light is in- dispensable − below that threshold (~300,000 km/s), any interaction between civilizations of different planetary systems would take cen-