I GREW UP IN BRISBANE, AUSTRALIA, A SUBTROPICAL landscape teeming with alien life. In the mornings wallabies bounded about the house; at nights we looked out on a sea of cane toads; on summer evenings the skies filled with clouds of bats. Vast colonies of black-and-yellow caterpillars balled themselves into seething masses at the bases of gum trees, and through the undergrowth slithered more types of snakes than I care to recall. But one alien life form eluded me entirely.

As a child I was desperate for an extraterrestrial encounter; night after night I'd lie awake trying to will a spaceship to appear. Gradually I came to believe I was simply living in the wrong place. When in the sixth grade Tracy arrived at our school, my deepest suspicions were confirmed. Tracy was an American. She was so blond that over the summer her hair turned mermaid green from all the chlorine in the swimming pools. I was green with envy, a far less fetching shade, but above all I was jealous of Tracy because she had seen an alien.

One night she told us how she'd watched from her bedroom window as a spaceship landed in a field next to her house and little beings descended from it. I'd always known Australia was a terrestrial backwater; now I understood it was a cosmic Peoria as well. I could hardly begrudge the aliens their preference for America — judging by Get Smart and Dobie Gillis, it was a far more happening place. In Australia we never had UFOs, while America seemed awash in them.

In the new Mel Gibson film, Signs, America is once again inundated by aliens. Mel plays an Episcopalian priest who's lost his faith and is grimly determined to see everything through the stark prism of rationality, so when a huge circular hieroglyph appears in his corn field, his chief emotion is anger — at the supposed hoaxers — rather than awe. But soon the skies are ablaze with lights, and Mel's fields are echoing with unnatural sighs and whispers. So begins what I'd hoped would be a new Close Encounters, a delicate reflection on celestial friendship and our seemingly ingrained desire not to be alone. Call it wishful thinking.

Nature abhors a vacuum, Aristotle said, and so apparently does human imagination: Looking up to the heavens at the void left by the departure of angels, we seem almost compelled to repopulate the empty space. No wonder that when glyphic formations began appearing in English fields in the 1970s, cosmic connections were soon being drawn. At first there were only simple circles; then additional rings, supplementary “satellite” circles, crescents and crosses were added to the typography. Before long a pictographic mania began to take hold of the cereal artists: Fractal forms, snowflake constructions, geometric diagrams and Sumerian symbols were realized. Each year designs grew more elaborate, and crop-circle watchers took to giving them names: the “Bythorn-Mandala,” the “Dharma Wheel” of Silbury Hill, the “Cobweb” formation of Avebury, the Cambridgeshire “Mandelbrot Set.”

The more complex the “agriglyphs” became, the more convinced were true believers of their extraterrestrial origin. In 1992, English crop-circle expert George Wingfield told a rapt L.A. audience that when a formation is fresh, strange electromagnetic signals emanate from the crushed stalks — proof, he said, that they could not be made by human hands. He went on to relate how he and a group of colleagues had spent a night on a hill meditating on a particular symbol, which by the following morning had been made manifest in a field nearby. With these pictograms, Wingfield explained, the aliens were trying to communicate with us, and clearly they could read our minds.

Alien psychic powers are a truism among crop-circle believers. Writing in the forthcoming book Messages From the Space, Jay Goldner asks, “Do the still mysterious artists use intelligent plasma-vortex rays?” More important still is “the question of what kind of mental powers are able so eloquently to control these superior mental laws?” For believers, the crop-circle architects are a higher, more evolved and definitively benign species; like the shimmering beings of Close Encounters, they descend from the stars, bestowing on this terrestrial realm a semidivine grace. They are angels in technological guise.

But there are dark angels too — demons they are called — and it is to this dispiriting camp that the circle-makers of Signs belong. In M. Night Shyamalan's hackneyed examination of faith, the corn patterns serve as nothing more than navigational aids for an interstellar fleet whose sole purpose is to “harvest” humans. Global conflict ensues, though the only action the audience sees is when Mel's brother (Joaquin Phoenix) beats a single alien to death with a baseball bat and a glass of water.

The kind analysis is to see all this as an argument against military buildup: If our boys can defeat an “alien” army with baseball bats and water, what need for intercontinental missiles and nuclear arms? From the aliens' point of view, however, the word that comes to mind is slander. In three decades of crop-circling, nary a shot has been fired, from space or anywhere else! What sort of twisted mentality would demonize this patently innocent enterprise? For 30 years, these silent glyphographers have decorated fields with what constitutes one of the greatest bodies of land-art the world has ever seen. Against the striving for immortality that drives so much cultural production today, crop circles are distinguished by their very transience, lasting only till the end of a season. At a time when our artistic landscape is dominated by monumental egos, the anonymity — the sheer modesty — of this work commands our respect.

Signs notwithstanding, almost all crop circles so far have appeared in Europe, with 80 percent in southern England. In the U.S., aliens generally have less aesthetically inclined pastimes — sticking probes up people's bottoms, for instance, or performing weird sexual and reproductive experiments.

Perhaps we get the aliens we deserve. Can it be coincidence that European extraterrestrials express themselves artistically while American aliens seem obsessed with sex and world domination? In a recent book on science-fiction cinema and Western imperialism, Aliens R Us, Muslim philosopher of science Ziauddin Sardar argues, like C.G. Jung and others, that our aliens are not a representation of anything Out There but an index of our own pathologies. By this light, Shyamalan's film is less a meditation on faith and more an exercise in plain old paranoia.

IF CROP-CIRCLE BELIEVERS ARE UNLIKELY TO BE happy with Shyamalan's cosmic xenophobia, they also reject the idea that human beings are responsible. Since the late '80s, hoaxers have increasingly laid claim to various formations; today there are even crop-circle competitions where would-be masters of the cereal universe can demonstrate their skill. (Contestants are judged both by the formal beauty of their designs and by their stealth — Rule Number One: Leave not thy Milk Duds packets in the cornrows.) Circle experts are scathing of such efforts, claiming that “real” formations can readily be distinguished from “fake” ones.

In the new documentary Crop Circles: Quest for Truth (opening at the Nuart August 23), one expert asks: If not extraterrestrials, who could possibly carry off such a widespread and multivalent spectacle? Some years ago in The Cereologist: The Journal for Crop Circle Studies, Merrily Harpur proposed an intriguing possibility inspired by the example of British artist Brian Catling. In his youth, Catling made miniature caskets into which he would put bizarre, exquisitely wrought objects such as tiny sculptures fashioned from fingernail parings. Catling would send these packages randomly to people whose addresses he'd gleaned from suitcases on railway platforms and bus stations, never knowing, as Harpur puts it, whether these gifts “went into mythology or into the bin.” As the source of crop circles Harpur proposes a small army of Brian Catlings, a group of individuals modest in spirit, aesthetically fluid and anonymously committed to “enchanting our conceptual landscape.”

Why would anyone bother? Harpur posits the Catling Factor, to wit: “It is impossible to overestimate people's powers of imagination, or their capacity for taking pains, or the inscrutability of their motives.” Motive is the true enigma of these extravagant forms — at once ecologically benign and technologically portentous, as signs crop circles can sustain almost any interpretation we care to read into them. In this, our semiotic age, they are the perfect postmodern mystery.

LA Weekly