After Asaph Hall discovered Phobos and Deimos in 1877, some astronomers like Schiaparelli thought they saw what he called "canali". Because , at the time, the Suez Canal and the Panama Canal were in the news as being mankind's greatest technological achievements, the canal theory was proposed for what was seen on Mars: water for the dry equatorial areas and therefore, Mars was inhabited by a technological civilisation.

But Antoniadi knew better.

Then, there was Herbert George Welles with his "War of the Worlds" book.

The book is a denunciation of the British Victorian colonial empire.

In 1938, Orson Welles made history with his radio broadcast of the same HG Welles story! This time, the culture behind it was the fear of being invaded by the evil dictators or the communists from central and eastern Europe, and Asea.

Then, Mars came back in the form of UFO's, also in a Cold War atmosphere. After all, UFO pilots had to be ...martians!

Then finally, Mariner 4 saw craters on Mars. Ouch, no Martians, just craters like on the Moon. Ah, but only a tiny fraction of the surface was pictured...Let's try again
Mariner 6 and 7.
Some had hoped, at NASA, that the Mars flybys, right after Apollo 11, could convince the White House, congress and the media, that it had another goal to reach: Mars! But...aaargh, again craters...craters like on the Moon...How can you sell Mars that way?
And there no more were high hopes for a manned Mars expedition.

Nowadays, there are concerns about genetically altered food, pollution, diseases, greenhouse gases, global heating....and returning samples from Mars fits right in thoses concerns.

How our perception of Mars changes with time, according to the mood!
What kind of mood could take astronauts to Mars?
Time will tell.

Raoul