The Canals of Mars

One of the greater mysteries of Mars is that Lowell and Flammarion were apparently correct in their observation that large and seemingly straight linneae are present on Mars, though only very few of the ones we discovered match the maps drawn by them. These features are so far mostly concentrated in the shrubland regions, most beginning in the slope-regions of the southern highland and radiating out into the lowland deserts, sometimes joining with ancient craters. Sometimes these lines will join each other or at the same crater, with new lines also seemingly flowing out of the craters. While often only ten-or-so metres wide, some of these features have impressive lengths, the longest one so far discovered reaching from the slopes of Alba Mons all the way to the Milankovič Crater.

My own sketches overlain with those of Lowell. Though in my case, all the canals were actually buried underground beneath the sands.

What is weirder is that almost none of them were actually visible on the surface when we arrived, instead the “canals” were discovered by accident during seismic measurements, as they lie many tens of meters under dust and sediment. This further makes it doubtful that these are the same as Lowell’s canals. Though the excavation of one “canal” concluded that it was only buried a few centuries ago by a series of large global dust storms. Possibly then, Lowell and Flammarion had the luck of seeing these when they were still uncovered. It is also possible that far more such features exist across the Martian globe, though they lie now deep underneath dust and permafrost.

Now of course, it is very attractive to think that these may have been created by intelligent life, possibly as a form of irrigation system. Apart from their remarkable straightness, there is however nothing else that might corroborate artificiality. At least in the ones we excavated, natural geologic flowing features are observed and at the meeting points of the “canals”, where one might expect settlements, nothing has been found that would raise an archaeologist’s eyebrow. It should be noted, however, that we do not yet know how old these features are. Who is to say that after millions or billions of years, features like the Panama- or the Suez-Canal might still be recognisable as man-made?

Seeing no direct evidence to the contrary, it is nonetheless still preferable to interpret these features as being of natural origin. A common geologic feature observed inside their bedform are so-called antidunes, a form of ripple that forms in supercritically flowing water, which due to the lower gravity is expectedly more common on Mars than on Earth. The “canals” might therefore be the remains of highly unusual, massively sized flooding events. During times of intense melting, either through supervolcanic eruptions or freak heatwaves in the South, enormous amounts of meltwater may have flowed down the highlands into the deserts. The waters may have eaten their way through miles of previously super-dry and uncompacted sand and dust, which, once wetted, may have solidified into walls. On repeat-floods, these may have controlled the flow of water into straighter directions, eventually forming long, canal-like forms. This is more of an attempt at an explanation than an actual explanation and it is entirely predicated on the possibility that the low gravity of the Red Planet makes water behave differently than on Earth, because there is no Terran structure comparable to these flow-features.