- The red planet has captured our attention throughout human history.

With its relative proximity to us and to the Sun, early astronomers thought it was possible for life to exist on Mars.

We've imagined Martians as everything from humans with silver antenna to skeletal invaders with exposed brains; from a helmeted cartoon, to muscular four-armed bipedal warriors and whatever this thing is.

PBS even has its own Martians.

(scary music) (puppets yapping) Some Martians are depicted as monsters while others are allies.

Why are they all so different?

Technology plays a role, and so does biology, natural history, and war.

But the whole Martian craze began with just a single mistranslated word.

(exciting orchestra music) I'm Dr. Emily Zarka, and this is Monstrum.

The modern history of Mars began in 1877 when a crucial discovery was made, a network of lines was visible on the surface.

The Italian astronomer who discovered these grooves named them Canali, channels in English.

In 1895, astronomer Percival Lowell published the first illustrated book on Mars.

Lowell observed the same lines and writing for an English speaking audience, translated the word canali to canals rather than channels.

And that's when a fateful mistranslation changed Mars history forever.

He speculated how life could survive there if it did indeed exist.

But then, Lowell's theories got a little out there.

His book claimed that the surface markings visible on Mars were deliberate as "no natural theory has yet been advanced "which will explain these lines."

He theorized that what he was seeing were changes in vegetation made possible by a vast series of irrigation canals.

And even though he insists that he is only referring to the possibility of an intelligent life form on Mars, he also says, "Certainly what we see hints at the existence "of beings who are in advance of, not behind us, "in the journey of life."

Now that a scientist has suggested intelligent life on Mars, the public couldn't get the idea out of their heads and the press had a field day.

Newspapers and magazines reprinted Lowell's maps adding a visual element to Mars mythology.

Depictions in literature at the time presented Martians as humanoid in form and their society Utopian, no war, no poverty, no social classes, no prisons, and no alcoholism.

Martians were portrayed as advanced beings both in technology and intelligence.

They were odd, but kind of appealing until the War of the Worlds, that is.

No, not that one.

Nope, not that one either.

Further back.

Yes, this one.

Not only did H.G.

Wells give us one of the first alien invasion novels of all time, his Martians were very far from human.

Although they did possess a superior intelligence, they also wanted to kill humans and inject themselves with our blood.

Initially serialized in Pearson's Magazine in 1897, the story was collected and published as one volume in 1898 and was an immediate success.

It has never been out of print.

It increased in popularity after Orson Welles' infamous radio broadcast in 1938.

On October 30th, listeners tuned in to hear his dramatic reading of the book.

- [Orson Welles] Ladies and gentlemen, I have a grave announcement to make.

Incredible as it may seem, both the observations of science, and the evidence of our eyes, lead to the inescapable assumption that those strange beings who landed in the Jersey Farmlands tonight are the vanguard of an invading army from the planet Mars.

- The show was so realistic, he managed to convince some people Martians were actually invading New Jersey.

Other than my beloved Yip-Yips and Marvin the Martian, theses were the first aliens I was ever exposed to and they left a lasting impression.

How could they not?

After all, H.G.

Welles' aliens were essentially giant heads about four feet in diameter with no nostrils, a fleshy beak, large eyes, and 16 tentacles arranged in two bunches.

Their internal structure was basically all brain.

What was so scary about these Martians was their advanced war machinery.

Welles describes a monstrous tripod a hundred feet high capable of traveling with the speed of an express train.

These machines driven by the Martians, have flexible metal tentacles, heat ray guns, and a chemical weapon in the form of black smoke.

See, terrifying.

In what is regarded as one of the best plot twists in science fiction, the Martians are destroyed.

Not by human military or weapons, but by bacteria.

While serious persistent criticism of the supposed canals on Mars began the 20th century, that did not stop authors from writing about life on the red planet.

Some authors latched onto Mars as an unchartered frontier ripe for a nostalgic romance driven by masculinist fantasy.

A place for swords and magic, geece and treasure, slave girls, princesses, and other beautiful female Martians just dying to be loved by a human man.

Even film picked up on this trend.

Following World War I, we see a shift in Martians.

The human explorers traveling to Mars in these texts were met with menace.

We see a surge of non-mammalian extraterrestrials similar to earthly insects, reptiles, or worms that were, more often than not, predators.

Stories of aliens from this period could be read as American anxieties about nationalism and racial segregation.

When Martians were described as more humanoid, they were still a threat because of their advanced weaponry.

It wasn't really until after World War II that Martians were more commonly referred to as aliens.

The word alien was specifically linked with a new term and concept for the time, the unidentified flying object.

As consumer cameras and recording devices became more more accessible, so did the popularity of UFOs.

People could now capture and share alien experiences.

Martian literature post World War II reflected a desire to escape Earth.

To flee from repressive governments, nuclear weapons, and other human created evils.

Like in The Martian Chronicles where humans flee Earth for various reasons including nuclear war, government censorship, and racism.

As its author, Ray Bradbury, once famously said, "Mars is a mirror, not a crystal."

As our science and technology advanced, and the idea of life of Mars was largely debunked, a belief in Martians became even more of a fantasy.

After the invention of in-space telescopic photography, and the Mariner 9 and Viking missions, people pretty much gave up hope that above ground organisms lived on Mars.

Of course, this hasn't stopped people from creating stories about them.

(eerie music) Mars is more visible and more accessible to us than ever.

Though many still hold out for the possibility of life on Mars very deep below its crust or in the polar ice caps, we are more concerned with trying to put humans on Mars than encountering some kind of life form there.

Today, narratives about Martians have changed.

We've moved away from imagining Mars as a preexisting Utopia populated by a Martian race superior to our own.

Now, we envision Mars as a Utopia in waiting.

A promise of hope and a better life off planet for Earthlings.