Wonders of the Solar System on the matter that composite the rings - a phenomenon called orbital resonance. The third episode looks at the atmosphere of the planets and moons of the Solar System, with Earth, Mars, and Venus being the main focus. The episode starts with Cox travelling to South Africa and taking a journey in an English Electric Lightning up to an altitude of 18 kilometres where the "thinness and fragility" of the atmosphere could be observed in the middle of the day. This is then contrasted with the planet-wide consequences of Mercury's depleted, and Venus' broiling greenhouse atmospheres. Later, the dunal morphology
Stranger from Venus field. This disruption would then affect the orbits and gravitational fields of all the other planets in the solar system. The stranger makes a promise that if Earth eliminates these dangers, Venus will share some of its higher scientific knowledge with our scientists. During the meeting, however, the man from Venus concludes that humanity is not yet ready to receive such advanced knowledge. After his communication disc is stolen, which allows him to contact the approaching Venusian ship, the stranger quickly realizes that an interplanetary meeting of minds can never take place. He also learns that such a meeting will