Tuesday, March 29, 2005

Down the Tubes?

A photo released by Malin Space Science Systems (see S03-00125p.gif) casts further doubt on the alleged artificiality of the Martian "tubes."

A three-dimensional tube? Not quite.

Alternately know as "tunnels," the features garnered intense interest after Richard Hoagland pointed out a striking example showing what appeared to be, on first take, a shiny spherical object embedded in a clear elastic carapace. Although subsequent shape-from-shading renderings strongly suggested that the seeming "tunnel" was in fact a series of natural-looking rilles (and not a three-dimensional "tube"), the sheer number of tunnel-like features invigorated an online community certain that high-resolution imagery from the Mars Global Surveyor would betray smoking-gun evidence of alien architecture on the Red Planet.

Seen up close, the supposedly arched "rungs" of a typical tube are less-than-impressive.

Despite the very un-intelligent placement of many candidate tubes, the prospect of an ancient civilization using a globe-circling network of enormous cylinders to transport water, material and/or personnel (a la Percival Lowell's illusory canals) continues to exert huge appeal. And while there are indeed regularly spaced bright markings on the Martian surface that await explanation, notably in the Cydonia region, the number of "false positives" has hindered objective analysis.

Unexplained bright markings atop the Cliff in Cydonia.

Tellingly, the tubes have become almost as well-known as standby surface anomalies such as the Face, and have become a staple interest among Mars-watchers with a planetary SETI bent. My first answer to those who inquire about the fabled "glass tubes" is that, contrary to their monicker, the features are neither glassy nor tubular. Of course, a vocal minority continues to claim otherwise.

An anomalous tube-like feature emanates from the eastern "wall" of the Fort.

As with the "banyan tree" formations cited by Arthur C. Clarke as evidence of thriving Martian plantlife, NASA/JPL has been mostly silent on the tubes, prompting conspiratorial allusions by Web-based commentators. The new image, with its inherent sense of disappointment, has already become the victim of "coverup" accusations; some see it as a digital scam designed to nullify public enthusiasm. (Such an act is not without precedent. When the Mars Global Surveyor transmitted the first detailed image of the Face in 1998, JPL hurriedly subjected the picture to a high-pass filter that helped stifle the feature's humanoid likeness.)