(Painting by David Egge, reproduced courtesy of
Novaspace Galleries).

Mars in History

The history of our thought on Mars goes back to the mythological associations. The red color and rapid motion of Mars seem to have universally been matched to martial characters - Mars, Ares, Norse Tyr, Maya , Chinese "Fire Star". Incidentally, "what color is Mars?" is not quite the simple question that its nickname would suggest.

Johannes Kepler derived his three laws of planetary motion starting with Mars - a fortunate choice since this was the only planet easily observed for which the orbit is elliptical enough to make it clear that it was not a circle (even an off-center one). This broke an ancient prejudice that even Copernicus hadn't given up, that heavenly motions must be perfect, uniform, and circular.

An odd interlude concerns the moons of Mars. For a while, some people suggested that simple numerology required Mars to have 2 moons (Earth has 1, four were known for Jupiter...). Two were indeed discovered and named Phobos and Deimos by Asaph Hall at the US Naval Observatory in 1877. These are tiny (Deimos is still the smallest known natural satellite, only 7.5 km along the major axis of its potato shape), and Phobos has the distinction of being the only moon to orbit faster than its planet rotates, in a mere 8 hours. Remarkably (presciently, spookily, by purest chance) moons with similar properties had been described in the purely fictional setting of Jonathan Swift's Gulliver's Travels, published in 1726. Describing the Laputans and what the found from their flying island, he wrote, "They have likewise discovered two lesser Stars, or Satellites, which revolve about Mars; whereof the innermost is distant from the Center of the primary planet exactly three of his diameters, and the outermost five; and the former revolves in the space of ten hours, and the latter in twenty-one and an half...". Not too bad. I can't prognosticate that well by trying very hard; some folks have all the luck, but then Nobel hadn't established his prize yet anyway.

It has always been tough to see specific details on Mars from the Earth, because it's small and the markings are not very distinct (for the picky ones, they are of low contrast). To make this point, here's a photo taken with our 10-inch refractor on November 25, 1990, the last time Mars was nearly as close as we see it during the 2003 apparition:

This (and your own eyepiece view, likely to be somewhat clearer) will show why it was possible for astronomers to argue so long about what could and could not be seen. If only we'd had digital cameras and image processing...

A whole new epoch in Mars studies came with the reports bi Giovanni Schiaperelli in the 1860s that he saw numerous channels (canali), immediately and sloppily translated into English as "canals". The implications were rather different... The existence of the canals was a matter of heated debate for decades, with skilled observers being either utterly convinced of their existence or equally convinced that they were misperceptions of scattered details. Clearly the dean of canal theorists was Percival Lowell, who had enough personal wealth to build an observatory in Arizona (Flagstaff was then a Wild West train stop) with one of the world's most powerful telescopes. He built up a map of Mars and its change with time which included a global network of narrow lines, often double, crossing the deserts and pulsing with the changing seasons. This composite is taken from his book Mars as the Abode of Life:

Lowell argued for a planetwide civilization, working together for the stewardship of the planet's shrinking water supply. The only problem is - the canals don't exist. They don't match the places where we see (much smaller) winding channels that look like riverbeds or flood erosion...

Lowell described his observations and interpretations in a series of books which were classics of exposition and argument (even when totally bogus, as in his argument about why focus within the eye couldn't possibly make canals look double - hint: we don't see Mars, we see its image). The first of these, Mars from 1895, is sometimes available as on-line text (that site was partially reorganized as of August 2003 so the contents but not text were accessible).

More is set out in William Sheehan's book The Planet Mars: A History of Observation and Discovery, which has generously been made available online by the University of Arizona Press.

There's a little piece of West Alabama on Mars these days. Areas on Mars as mapped from Earth bore mythological names - Hellas, Edom - or obscure Latin names - like Syrtis Major. Close-up mapping revealed physical features that demanded names, such as volcanoes, canyons, channels, and craters. Most craters took names from astronomers who were noted in the study of Mars (Schiaperelli, Lowell), but right there at north latitude 18.7 degrees and west longitude 54.6 degrees, appropriately on the edge of a flood plain, you'll find - Northport! It seems a UA alumnus (who probably wants to remain anonymous) was involved in the mapping, and managed to add a little bit of home. It's in the middle of this map section (click on it to get the USGS version that you can pan and zoom):

Marsfest | Bill Keel | UA Astronomy | Dept. of Physics and Astronomy | University of Alabama

Last changes: August 2003