Thursday, August 05, 2004

More Pareidolia

I wrote a while ago about the way in which the human mind's hunger for patterns often misleads, and now Wired has gone and written more about the issue, this time in the context of the notorious "face on Mars."

Mars began its career as a cosmic Rorschach blot in 1877, when the Italian astronomer Giovanni Virginio Schiaparelli stared through a 9-inch Merz refracting telescope and declared that the spidery lines he saw etched on the planet's surface were "canali." What he meant was channels, but the English-speaking press, still hopped up on the recent opening of the Suez Canal, settled on the sexier term canals. In the US, the amateur astronomer Percival Lowell widely publicized his conviction that the splotches and lines revealed by his observatory's 24-inch telescope suggested vegetation and alien-made waterworks.

In 1964, a NASA probe took the first pictures of the planet's surface, shattering Lowell's visions of Martian gondoliers. But with every increase in camera resolution, some new oddity emerges from the Mars pixels. In 1976, when a Viking probe passed over a region named Cydonia, the orbiting craft took a fuzzy picture of a huge mountainous structure below. In a subsequent press release, NASA announced that this mound "resembles a human head formed by shadows giving the illusion of eyes, nose, and mouth." The space agency was probably just trying to stir up public interest. Yet as anyone who has ever scanned the racks in a supermarket checkout aisle knows, it stirred up a hornet's nest.

Hornet number one is a fellow named Richard Hoagland, a science writer who subsequently built a small empire atop the "face on Mars." Besides the face, Hoagland identified several other "artificial" structures in Cydonia and connected them all in an elaborate numerological network. On NASA's next mission in April 1998, the agency felt obligated to steer the Mars Global Surveyor over Cydonia to photograph the face on two separate occasions. What the images revealed - to most eyeballs, anyway - was a pile of rubble.

This didn't stop Hoagland, a passionate man who continues to present his theories of Martian civilization to the likes of Art Bell on the fringe-dwelling Coast to Coast AM radio show, not to mention his own Star Trek-flavored His claims are regularly attacked in withering geek style by Phil Plait, NASA education resource director at Sonoma State University in Northern California, who describes himself as the "go-to guy for astronomical debunking." Plait runs, which metes out the drubbings that NASA is too politic to deal with itself. After an article about the Hoagland versus Plait feud appeared on in March, Plait's site was overwhelmed with millions of hits. "I love getting angry email from my sysadmin," he chuckles.

Though Plait has no respect for Hoagland, whose evidence he regards as "crap," most of the people he goes after are "not necessarily fraudulent evil bastard liars," but merely deluded. Plait spent five years processing Hubble images at NASA's Goddard Space Flight Center, and he knows how tricky astronomical images can be, even for trained scientists. One of the main problems with the anomaly crowd, he says, is pareidolia: misperceiving a vague but suggestive shape as something definitive. "It's very clear that human brains are designed to pick out patterns," says Plait. "If you can't pick out the tiger hiding in the grass, you are lunch; you don't reproduce." On the other hand, if you think the burn mark on your tortilla is actually the mother of God, you are probably suffering from pareidolia.

On the morning of November 4, 2003, Plait met his own anomaly: a face on his shower curtain. Plait quickly snapped a photo of the splotch and posted the apparition on BadAstronomy. Most of his readers agreed that he had been visited by Vladimir Lenin. Others insisted that the face actually belonged to Mark Twain, or even Colonel Sanders. "And that's my point," says Plait.
And what sorts of people tend to devote their energies to this sort of nonsense, one might wonder; well, wonder no more, as one prime example is described in the excerpt below:
Any time you interpret curious shapes, whether of sedimentary rock or ancient hominid bones, you confront the same faces-in-clouds problem: Is it there or am I imagining it? The difference with Martian anomalies is that hundreds of millions of people can directly point their Web browsers at the same cloud. "Because hard visual evidence is available and readily verifiable in NASA and JPL's own official science data, everyone can then make up their own mind as to its merit," writes Joseph Skipper on, perhaps the best one-stop shop for Martian enigmas. "No one's interpretation of the visual evidence should be considered established fact."

Skipper's site includes scores of annotated images, as well as claustrophobic commentary that scrolls on endlessly. In a report titled "The Real Smoking Gun as to Life on Mars," he discusses one of his most important discoveries: Photoshop. The graphics program, which allows the 61-year-old Florida insurance investigator to sharpen detail in NASA's images, "lifted the scales from my eyes." Besides finding evidence of life, Skipper also claims that NASA is tampering with the Mars images, removing evidence of alien life. Most of the smudges he points to look like artifacts caused by data compression; when Wired asked for clarification, Skipper refused to comment, citing nameless "adversaries."
I think that last sentence says it all, doesn't it?