The Gods of Mars the two Viking missions which found a dead, frozen world where water does not exist in a fluid state. The Valley of Dor, with the ring of cliffs around it and Sea of Korus within it, is placed in a mile-deep crater at Mars' South Pole. However, Burroughs makes a mistake in that he has the sun rise in the east and set in the west as elsewhere in the planet, and the moons are visible from the Valley. In reality, at the South Pole, Mars' moons would not be seen, and the sun would not rise in the east
The Secret of the Martian Moons that unlocks Mars’ secret. A political controversy is raging on Earth as to whether or not to continue to support the Martian outpost, where Nelson’s father is research chief. Those in favor point to the marvelous machines found on Mars, any one of which could advance civilization eons, if their secret could be discovered. Going to work on the problem, Nelson finds out – in an interesting chain of events that characterizes a Mars basically like the canal-covered red planet we know it to be now – that the Martian moons Phebos (sic) and Deimos, are centers of tyrannical factions