Episode number 4 of Series “Planet earth”.
Voyages to other planets have shown us that earth is unique. The question now is why? Through the use of little-seen footage shot in space, this program attempts to answer questions such as why there is no life on Mars and Venus, why the dinosaurs disappeared, whether earth has been bombarded by meteorites in the past. A fascinating look at the formation of the planets.
National Academy of Sciences (U.S.)