Mars, the red planet, the planet of war. Subject of unprecedented interest from space probes, and perhaps an eventual manned mission. Mars has been in the popular imagination for over a century. Mars fever started with Percival Lowell, who constructed a telescope a few hours drive north of me in the Northern Arizona desert to observe Mars at its closest opposition for over a hundred years. Lowell was a retired merchant from Boston, one of the founding families, one of the blue bloods of Boston, who retired and pursued his passion of astronomy. A wealthy man, he was able to build, single-handedly, a nearly two meter telescope in the Arizona Desert. At the time, it was the one of the world's largest telescopes and in one of the world's best sites for observing. Lowell used his new telescope to take the sharpest possible images of Mars. Although photography existed at the time, and you could record images, the seeing sharpens up momentarily, such that it's always best to see the sharpest images by eye. When the features would sharpen up as the seeing diminished, and things would be visible that weren't visible otherwise. Staring at Mars during its closest approach, Lowell imagined that the surface features were more linear than they really were, and he saw them as interconnected and artificial in nature. Gradually, a story built in Lowell's mind of a civilization dying on Mars due to the aridity of the planet. Who were building a series of canals to bring water ice from the poles down to the equator, where they lived. In Lowell's mind, Mars was a living planet. And of course, because he was making the best observations possible, no one at the time was able to confirm or refute his observation. Lowell was not trained as a scientist, but he was a good writer. And he started to write popular articles and eventually books on Mars which fueled the popular imagination that there was, indeed, life on Mars, not just microbial life, but an intelligent civilization. The ideas about life on Mars were fueled by a simple misunderstanding. When Lowell's observations of canals on Mars were translated into Italian, the word canale was used. Which in Italian just means channel. And does not imply artificial construction. But it was translated back into the United States in the literal form, as canals. So suddenly, the story was Lowell had seen canals on Mars. Lowell drew what he saw, or what he thought he saw. It was clear that he was using wishful thinking at some level. A telescopic observation recorded by photographic image doesn't show the sharpness of features that Lowell saw with his eye. Lowell was smart enough to know that a canal, maybe ten meters across, could not possibly be resolved at a distance of 50 million miles. So he hypothesized that he dark colorations were surrounding areas of vegetation formed along the canals, and fed by the canals. Even around the time of Lowell's work planetary scientists did simple calculations to show that Mars couldn't hold a thick atmosphere. And so it was exceptionally unlikely to be able to host liquid water. But that wasn't proof and Lowell's speculations held sway. We can flash forward nearly half a century during a period of time when science fiction took off. Edgar Rice Burroughs wrote lurid fantasies about living creatures and man-like creatures on Venus and Mars. So the popular consciousness took hold that there must be life on Mars, perhaps war-like, perhaps benign. In 1938, a brilliant young director called Orson Wells had a series of radio plays. The actors he used were some of the best names in acting of the second part of the 20th century. Wells was what's called a wunderkind, far ahead of his time with clever ideas, precocious and very sure of himself. One evening, Wells and his Mercury Theater released a story on live radio of Mars coming to the Earth in the form of a violent attack, an invasion. We have to understand the time and place. This was the East Coast. People got their information by radio. TV existed, but hardly anyone owned a TV. Radio was an evocative medium. People were encouraged to form mental images, and the imagination could run wild. Also, 1938 was the eve of the Second World War. People were anxious about what was happening with Hitler in Europe and the invasion of Poland that was imminent. There was fear in the air. Wells was artful. He released a very short disclaimer at the start of the radio program. But if you tuned in late and missed it, you would have witnessed something that escalated, over a period of time, to frightening levels. He was, of course, doing a radio rendition of HG Wells famous book War of the Worlds released in 1905. A popular book in its own time, it played a good part in the idea of Mars as housing a violent civilization. At the start of the broadcast, an apparent program of dance music was interrupted by an anxious announcer. >> Ladies and gentlemen, we interrupt our program of dance music to bring you a special bulletin from the Intercontinental Radio News. At 20 minutes before 8:00, Central Time, Professor Farrell of the Mount Jennings Observatory, Chicago, Illinois, reports observing several explosions of incandescent gas, occurring at regular intervals on the planet Mars. The spectroscope indicates the gas to be hydrogen and moving towards the Earth with enormous velocity. Professor Pierson of the Observatory at Princeton confirms Farrell's observation, and describes the phenomenon as, quote, like a jet of blue flame shot from a gun, unquote. We now return you to the music of Ramon Raquello, playing for you in the Meridian Room of the Park Plaza Hotel, situated in downtown New York. >> After this, the music resumed. And there was several more interruptions. Finally, 15 or 20 minutes later, things reached a crescendo. >> Ladies and gents, am I on? Ladies and gentlemen. Ladies and gentlemen, here I am, back of a stone wall that adjoins Mr. Wilmuth's garden. From here I get a sweep of the whole scene. I'll give you every detail as long as I can talk. And as long as I can see. More state police have arrived. They're drawing up a cordon in front of the pit, about 30 of them. No need to push the crowd back now. They're willing to keep their distance. The captain is conferring with someone. We can't quite see who. Yes, I believe it's Professor Pierson. Yes, it is. Now they've parted. The Professor moves around one side, studying the object, while the captain and two policemen advance with something in their hands. I can see it now. It's a white handkerchief tied to a pole, a flag of truce. If those creatures know what that means, what anything means. Wait a minute, something's happening. [NOISE] A humped shape is rising out of the pit. I can make out a small beam of light against a mirror. What's that? There's a jet of flame springing from the mirror, and it leaps right at the advancing men. It strikes them head on! Good Lord, they're turning into flame! >> Aah! >> Now the whole field's caught fire. [NOISE] The woods, the barns, the gas tanks, tanks of the automobiles. Spreading everywhere, coming this way now, about 20 yards to my left. >> At the end of this announcement, Wells left ten seconds of dead air, absolute silence. In broadcasting, it's known that if you want to grab people's attention you say nothing. You never leave dead air. Wells did it to heighten tension and anxiety. And sure enough, reported by other radio stations, within an hour of the end of the broadcast people were piling their family possessions into their wagons and jeeps. And anything they could handle, anything they could bring, and escaping their houses, fleeing, who knows to where. The highways around New Jersey were clogged, police switch boards were jammed. There was panic, pandemonium. Tens of thousands of people hit the roads. It was, of course, a hoax. Interviewed later, Wells disavowed all intention to fool people, but anyone who knew him knew that this was fully intentional. He was harnessing Mars fever and fear. Whatever the truth of the situation, people were ready to believe in life on Mars. If we look at Mars, Mars is not really a close twin of the Earth. That role goes to Venus, in the solar system. Mars is substantially smaller and less massive than the Earth and retains an atmosphere of barely 1% of the density of the air we breathe formed almost entirely of carbon dioxide. 50% further from the Sun than the Earth, it receives less than half of the Earth's radiation. So it is cold place. The thin atmosphere and cold temperature means it's impossible for water to be liquid on the surface of Mars. And that's been known for nearly a century. By coincidence, Mars has a similar axial tilt to the Earth, which means although it has a longer orbit around the sun, its seasonal variations are similar. If we look at a surface of map of Mars, we can see some of the places we've visited on the planet starting with the twin Viking Landers in the mid 1970s and continuing through the small twin Rovers of the last few years. Not represented on this map are the Phoenix Lander, which was operated out of the University of Arizona and went to a north polar region, and the recent Curiosity mission situated in Gale Crater and currently exploring the red planet. A geological map of Mars shows that the surface is mostly old. This is a sign that volcanism is not that important on Mars, except episodically. Most of the surface is old, eroded by craters and not resurfaced by tectonics or volcanism. A comparable map of the Earth would look quite different. There's hardly any Archean crust or rocks dating from 3.8 billion years or older. Whereas, Mars has a significant fraction of its surface that old. On the Earth these ancient rocks are almost impossible to find, so active is the geology of the Earth and so heavy the level of erosion of the surface. Although Mars is nearly geologically dead, it's not completely boring. Close inspections through rovers and obitors has shown that it has weather, it has a mild hydrological cycle. Rhere clearly has been volcanism. Olympus Mons is a prodigious volcano, the largest in the solar system. And the rovers and objects we left on the surface have shown that there are dust devils and widespread dust storms, on occasion. Mars is mostly geologically dead, and has a very thin atmosphere, but it's not a boring planet. It has a hydrological cycle, it has weather, and there's strong indirect evidence that it was wet in the past. The historical Mars has been assumed to be alive due to the fantasies of HG Wells, the observations of Percival Lowell, which indicated canals in Mars, although he was mistaken. And the radio show of Orson Wells, unrelated to HG Wells, which fueled fervor that Mars was inhabited by a dying civilization transporting water from the poles to the equator.
