Are we alone in the universe? What may seem like a simple and intuitive question is perhaps one of the most complex and as of now unanswered questions to be pondered in human history, a question that was first contemplated by our most distant ancestors and one that still pervades us to this day. While we may not know the answer to this question with respect to the entire universe, we can be reasonably confident due to decades worth of study that our solar system, Earth’s local environment in the cosmos which includes all that orbits the Sun, is in fact lifeless.

This bleak view of our solar system has led us to the now common, modern portrayal of the Earth as a lonely world within the cosmos, a beacon of life in an otherwise lifeless universe. This view of the universe wasn’t always the case, however. Not so long ago, when our knowledge of the cosmos was particularly limited, astronomers viewed our solar system in a very alien way. With so little information about the nature of the solar system available to them, their minds were allowed to roam free about what lay out there on the many distant abodes that we call planets. Thus, from the period between the 17th and 20th century when we began to peer ever closer to the planets of our solar system thanks to the invention of the telescope, astronomers caught sight of what they believed to be architecture on these distant worlds, and architecture to them was the telltale sign of intelligent life. Whether these sightings were misinterpretations of natural terrain, optical illusions caused by their telescopes, or simply tricks of the mind due to these astronomers’ fantastical expectations of these worlds, the reality is that for over two centuries most of the astronomical world became convinced that there were vast, intricate canals connecting numberless colonies on Mars, planetwide cities on Venus, and above all, colossal megastructures on our very own Moon.

Various astronomers throughout history produced wonderful sketches of their discoveries. These sketches are incredibly beautiful, and while the people who looked to the skies were not architects, I believe there is a deep connection between their work and the work of architects. The astronomical architecture envisioned by these astronomers ultimately came from the imagination as they mentally constructed this fantastic architecture in their minds. Architects do the very same as they use their imaginations to plan and design their various buildings and structures. I thus believe these discoveries are of deep architectural value.

Lunar Life

Following the invention of the telescope independently in the early 17th century by Hans Lipperhey, Zacharias Janssen and Jacob Metius, a new era of space exploration was brought to life. In the proceding years many astronomers turned their telescopes to that of Venus, Mars or Mercury in the hopes of finally capturing a glimpse of the surfaces of these distant worlds that tantalized them for centuries. Young Polish astronomer Johannes Hevelius (1611 - 1687) had a different plan however, as he focused his attention to the ever-present focal point of the night sky, Earth’s lone natural satellite, the Moon.

Hevelius is often referred to as the founder of lunar topography for his immense contribution toward our understanding of the lunar surface and its finer details. In 1641, Hevelius constructed a 46-metre long Keplerian telescopeA which he placed atop the roofs of three adjoining buildings that he owned. This impressively crafted wooden structure was the device that which he planned to observe the Moon with.

Over the next six years Hevelius would produce at the time the most detailed and sophisticated drawings of the Moon, showcasing the lunar surface in unprecedent detail. Almost every prominent feature of the lunar topography was captured in Hevelius’ work, an incredible feat considering the very limited technology he had at his disposal. Hevelius had a deep belief that the terrain he was seeing during his observations was not entirely natural but rather altered by lunar inhabitants, which he referred to as ‘selenites’.1 This belief is reflected in Hevelius’ work, where ordinary, rugged lunar terrain appears oddly uniform and, in some cases, strikingly linear and perfected as if it were sculpted by the Moon’s inhabitants. Hevelius would collate his awe-inspiring, beautiful drawings of his discoveries on the Moon in his book Seleographia: Sive, Lunae Descripto (Selenography: Or, The Description of the Moon), and these became the first ever works to portray a deep sense of understanding of the lunar topography.2 Thus, Hevelius’ beliefs of the selenites and their landscape architecture echoed through the astronomical world and lived on for over a century as aspiring astronomers used Hevelius’ work to study the lunar surface themselves.

Upon looking at these drawings it is easy for one to understand why so many future astronomers would become convinced there was architecture on the Moon. Hevelius was not overly outspoken when it came to his views of architecture and life on the Moon in comparison to other astronomers, but in my opinion his drawings do the explanation for him, much like how a good architect’s drawings can do the talking. Of the many later astronomers to become convinced of lunar architecture thanks to the work of Hevelius, one such man was none other than world renowned German-British astronomer and discoverer of the planet Uranus, Sir William Herschel (1738 - 1822).

Herschel studied the skies in an era where telescopic power had increased tenfold compared to his predecessors. Herschel maximized the use of this newer technology as he surveyed the Moon, peering closer to the lunar surface than anyone before him, analyzing individual terrain formations rather than the whole lunar disk like Hevelius. During his countless hours of observation, Herschel became ever more convinced that what he was seeing in much finer detail than Hevelius was only reaffirming the Polish astronomer’s beliefs of lunar life. Unlike Hevelius, Herschel never produced any drawings of his discoveries, but rather wrote about them in his many diaries.

Metropolitan Moonscapes

Undoubtably the most fascinating of Herschel’s discoveries was that of the numerous lunar metropolises which populated the Moon’s surface. To Herschel, what we now know as ancient, dead impact craters were meticulously constructed, living metropolitan areas that which countless highly intelligent beings, which Herschel referred to as lunarians, dwelled within, “I am convinced that those numberless, small circuses (circles) we see on the Moon are the works of the Lunarians and may be called their towns.”3

As to why these lunar municipalities were circular in nature, Herschel reasoned it was due to the Moon’s thin atmosphere. Earth’s atmosphere helps to disperse and reflect sunlight, which results in any given area of Earth’s sunlit side receiving near equal volumes of light. This is to say that any building within a city that does not directly face the Sun still receives ample light. This allows architects on Earth to develop city plans without too much concern for the lighting, giving rise to the now commonly used and efficient Hippodamian plan of the city. The lunar inhabitants do not have this luxury, however. Without an atmosphere to disperse the sun’s light, any building not directly facing the sun will receive practically no light at all during daytime on the Moon. This is a big problem for city planning on the Moon, as many buildings would be left in complete darkness.

Herschel believed the lunarian architects had come up with an ingenious solution to the problem, however. By developing the plan of the city in a circle, the entire city effectively becomes a concave mirror, where the outer buildings reflect sunlight inward, illuminating all buildings within the entire metropolis, even if they were not directly facing the Sun, “There is a reason to be assigned for circular buildings on the Moon, which is that, as the atmosphere there is much rarer than ours and of consequence not so capable of refracting and reflecting the light of the Sun, it is natural to suppose that a circus will remedy this deficiency, for in the shape of the buildings one half will have the directed light and the other half the reflected light of the Sun. Perhaps, then on the Moon every town is one very large circus?”4

The idea of a circular city is incredibly fascinating, not just because of its unique form but rather because it takes something most architects work with, the survival of light within a building, and applies it to the scale of an entire city. Herschel was not an architect, but he clearly had the mind of one. Much akin to how an architect looks at an empty site and visualizes a building that may fit said site, to look upon those chaotic lunar impact craters and visualize an entire city, and to envision how said city plays with light, requires an extraordinary architectural imagination. I believe Herschel’s circular city is of deep architectural value as it demonstrates the architecture of both the individual building and the city working in unison to aid in the survival of light, a task we Earthly architects have not yet attempted to conquer.

Wallwerk

Unlike the true surface of the Moon, Herschel’s circular cities were not everlasting. Only half a century after their inception, fellow German astronomer Franz von Paula Gruithuisen (1774 - 1852) was actively trying to dispel Herschel’s idea of lunar towns. Gruithuisen was the main propellant of the meteorite impact theory, the idea that the numberless circular structures on the Moon were not meticulously constructed metropolises, but rather the result of rocks from space impacting the Moon at high velocity, producing gashes in the surface which he referred to as ‘impact craters’.

Despite Gruithuisen’s initial skepticism regarding astronomical cities however, he too soon became convinced that there was architecture on the surface of the Moon, though not in the places where his predecessors had been looking. Within his published pieces of writing Gruithuisen recanted how during his many hours of observation he could discern multiple architectural structures amidst the lunar highlands, the lighter-colored areas of the Moon’s surface. These structures included various canal-like structures used by the lunar inhabitants to transport water, smaller tomb and temple-like structures adjacent to the craters themselves presumably used for religious purposes, and even a colossal lunar city, which he documented in 1824.5

By far the most interesting and provocative of Gruithuisen’s discoveries was that of his gargantuan lunar city, which he named Wallwerk. To analyze this city, we first need to get a sense of scale. To the south one can see an impact crater, which Gruithuisen named Uohen. This crater has been recently identified as Schroter W, named after its discoverer Johann Hieronymus Schröter, and is measured at around 10 kilometers across.6 To add to this, the two large triangular objects to the north are mountains, which Gruithuisen correctly discerned, “The two high mountains in the north are natural objects.”5 The northern and larger of the two mountains appears to have a diameter of roughly 40 kilometers. Wallwerk, as Grutihuisen envisioned it, is the array of linear formations that lie between these two natural objects, “It is highly probable that these structures between [the crater and mountains] are artificial and serve as dwellings for the sentient beings of the Moon.”6

Using the two measurements of the crater and mountain we can get a rough distance between them and thus can calculate the entire area of the city using trigonometry. This distance comes out as 110 kilometers and assuming the city has a base width of 104 kilometers, this gives us an area of roughly 5,720 square kilometers. The larger of the two mountains in the north is comparable in size to Mount Fuji in Japan, however Wallwerk would be two and a half times the size of Tokyo, the largest city on Earth. This knowledge of scale helps one understand just how impressive a city of this magnitude is. Whilst the largest cities on Earth tend to have an erratic design to them as they were built upon over time with varying styles of architecture throughout different eras, Wallwerk has a clearly defined architecture governing the entire urban landscape.

The city has a neat, chevron shield-like design to it and there is a clearly defined boundary to the metropolitan area, that is to say that the city does not appear to taper out into suburban areas like cities on Earth do. At the center of this geometry there is a linear core of either one or numerous unified buildings running straight through the middle of the city from north to south, this core being an impressive 75 kilometers in length and over a kilometer tall, “the central buildings are several miles long and are under a mile in height.”5 There are also a series of branching buildings protruding from the core at certain set intervals, with there being open spaces presumably for recreational activities notched between each of these spokes. Each of these open spaces has a width of roughly 10 kilometers. These open spaces serve as an effective way to allow light into all sides of the immense constructions, but they also have a more ergonomic use; the buildings in this city are clearly colossal, continuous megastructures, and so the equally large open spaces allow for plentiful breathing space for the inhabitants of the city as to make sure they are not constantly suffocated by the near endlessly long structures. I believe this creates a remarkable duality of nature and artificial when viewing the city from above, and this duality ultimately creates the city’s characteristic chevron shield-like form.

Wallwerk as a whole is spectacular, and the city is of great architectural value. The entire city flows with its surrounding landscape, it looks as though it belongs in its place. Architects often strive to merge their buildings to the site, to make them one and the same, this quality of a building is regarded as a fundamental principle of good architecture. Unfortunately, this rarely applies to the scale of the city, the construction of our cities often leads to the destruction of nature, and the cities ultimately rarely look the part when compared to the surrounding natural beauty of the Earth. Gruithuisen’s Lunar City however shows how a city can look the part with the natural landscape, whilst still retaining the fundamental features that make a city efficient. To me the Lunar City is thus a piece of architectural beauty. Gruithuisen’s sketch and the way he chose to portray the city is also incredible, there are no lines used in the piece of work, the entire drawing is the sum of numerous blots of ink on a page, the darker blots represent shadow, whereas the areas with no blemishes represent areas exposed to sunlight. It gives the feel of an analytical architectural drawing of a city, where an architect is studying the dynamics of light and shadow amongst the structures, an architectural drawing in the truest sense.

A Sentinent Solar System

Gruithuisen’s Lunar City unfortunately marked the tail end of significant architectural discoveries on the lunar surface. As the magnifying power of telescopes improved rapidly in the 19th century, our understanding of the lunar surface increased exponentially with each passing year, and no other traces of architecture were to be found.

This did not hamper past astronomers’ determination to locate our extra-terrestrial neighbors, however. With so little known about the many enticing worlds of the inner solar system, the search for astronomical cities continued for over century. Throughout the 19th century and entering the 20th century, astronomical architecture was also discovered on both Venus and Mars, as we peered ever further into our cosmic neighborhood. Sentience it seemed pervaded the solar system. Many astronomers such as Camille Flammarion (1842 - 1925) and Percival Lowell (1855 - 1916) would produce intricately detailed drawings of their findings and write extensively about the architecture of our planetary neighbors just like Hevelius, Herschel and Gruithuisen before them.7 All of these works and the associated drawings have an incredible architectural sense to them, and it is a shame that much of these beautiful sketches have been relegated to the history books with many architects being completely unaware of the existence of these pieces.

Ultimately, what is most intriguing about this period of astronomical-architectural alliance is how not only did the astronomers believe the architecture they saw was real, but they were in total astonishment at what they saw. What these astronomers were seeing through their telescopes was undoubtedly beautiful; the bright, white, cloud-laden world of Venus, and the geologically diverse, rusty red, desert world of Mars, however it was the perceived architecture on these worlds that captured the awe of these astronomers more than anything, showcasing the power that architecture can have over people.

This feeling of astonishment is perfectly captured by Percival Lowell in a quote which he wrote whilst gazing upon Mars; “There may be celestial sights more dazzling, spectacles that inspire more awe, but to the thoughtful observer who is privileged to see them well, there is nothing in the sky so profoundly impressive as the canals of Mars.”8

The Search Continues

When I first learned of the fact that there was once such a close connection between the two worlds of astronomy and architecture for over three centuries, I was immensely intrigued, as one would never think there was such a relationship when growing up in the 21st century, indeed as previously mentioned, much of the work produced showcasing astronomical architecture has been lost in the history books. The primary reason this bond unfortunately no longer exists and was forgotten is due the dawn of the space age in the 1950’s, a time when the first space probes were sent to photograph our planetary neighbors in much greater detail than what could be achieved by any telescope. When these photographs returned to Earth, the true nature of these worlds was revealed; the lunar cities, the canals of Mars, the architecture of the Venusians, they were all found to be nothing more than odd, natural terrain formations. This was a somber moment in the history of astronomy, when the brutal reality hit many; we were alone in our solar system. The two worlds of astronomy and architecture thus began to part ways, it simply did not make sense to continue searching for astronomical cities, the planets of our solar system were lifeless, and the planets of other star systems were simply too far away to try and look upon.

This was over seventy years ago however, and the landscape of astronomy has drastically changed in the preceding decades. Telescope power has increased hundredfold since then. In 2022, the James Webb Space Telescope was launched, and once its mirror is fully calibrated, it promises to deliver us the first photographs of the surfaces of planets in other star systems. As the first images arrive back from these alien exoplanets, the search for astronomical cities will continue, and I believe we architects and our imaginations can help uncover these elusive cities. The possibilities of what could be out there are near endless, and whilst we search for life on these distant abodes we cannot limit the scope our search to the type of architecture that we find on Earth, the reality is alien cities will look nothing like ours.

We must think like those before us, the astronomers who poured their unfiltered imagination into the lenses of their telescopes. Whilst those astronomers who looked to the skies all those years ago were not architects, their work epitomizes exactly what an architect is; someone who imagines a structure that does not exist. Every building any architect has ever designed also started within the imagination. The imagination is ultimately what leads to new forms of architecture emerging, what was once an idea within one’s mind is finally realized within the physical world. If we take this imaginative architectural prowess and try to envision what forms of architecture may exist on these worlds, who knows what we may find within the first photographs when they finally come to the fore. The search for astronomical cities continues, and we architects can help to finally answer one of the greatest questions of all, are we alone in the universe?