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The "Glass Worm"

Table of Contents
Introduction
What Color is Mars? The Green Planet? The Glass Worm
Face the Face City Slicker The White Bunny
Bizarre Image Analysis Say What? (Updated March 24, 2004) Hoagland's Credentials
NEW! (March 13, 2004) Some fallout: Hoagland discusses these pages on C2C
Conclusions
Links of Interest

Contents of this page

Introduction to the Glass Worm

Mars is a weird place. No one argues that. I think the argument might be over just how weird Mars is. For example, does Mars host a species of giant glass worms, 50 meters across and kilometers long?

I'm guessing no.


a glass worm? So why would anyone, let alone someone on Richard Hoagland's website, say otherwise? Well, probably because of the image shown on the right (clicking on it will display a much larger version), taken by the Mars Orbiter Camera onboard the Mars Global Surveyor. It's not hard to interpret this image as some long, convex, glass-like structure. It really does look like it's an enclosed tube. It looks shiny, and the arcs going across it look like for all the world (or worlds) like ribs, or the little segments in an earthworm.

On Hoagland's website, he has a page about all this written by Ron Nicks, who claims to be a geologist. Nicks makes lots of claims about this feature, and in fact says the following:

This remarkable "tube," roughly a mile in length and hundreds of feet wide, appears to cling to a desert canyon wall near the canyon's bottom, and extend along its entire length. The feature has the appearance of being "translucent," of being supported at somewhat regular intervals by "ribs," and of being quite cylindrical -- with a localized, internal structure at one point of considerably higher albedo (brightness).

[Note added March 30, 2004: In the original version of this article, I said that Ron Nicks was concluding this feature was an actual living worm at some point in the past. I was wrong. He does not say this in reality; he actually says that the lack of food for something this size precludes a natural biological origin for it (he does claim it is some sort of construction project, though). When I read the article, I misread that statement. However, this doesn't negate the other points I make below, especially the key one about optical illusions.]

Nicks' description is wrong in almost every detail he describes. Now, most people looking at the image would certainly agree with Nicks' analysis at first. I mean, it does look like a worm! It looks so much like a worm that no less a figure than Arthur C. Clarke has commented on it. In an interview by Louis Friedman of the Planetary Society, Sir Arthur said: "I'm still waiting for an explanation of that extraordinary glass worm on... [Mars]... How big is it? It's one of the most incredible images that's ever come from space and there have been no [official] comments on it whatsoever!"

I will state here that I am a great fan of Sir Arthur's. His stories helped inspire me to be an astronomer. It is not too much of a stretch to say that we owe our very presence in space to Arthur C. Clarke! But I think that in this case, I must disagree with him. This thing isn't a worm at all, and in fact has few of the properties ascribed to it by Nicks (speaking for Hoagland by proxy) and others.

The Convex/Concave Con

First off, they claim the object is convex, that is, popping out of the image as opposed to being a concave valley. However, I think this claim is false. To see why, look at the images below. They demonstrate an illusion where craters can look like domes if flipped upside-down.

Is it a dome... ... or a crater?

This illusion is pretty cool, though some people have a harder time seeing it than others. Ironically, it is not all that strong to me in the pictures above, but my wife thought it was remarkable how much the image on the left looked like a dome. I have seen other examples, though, and this illusion can be pretty convincing.

But does it work for the worm? Let's see:

Is it a worm... ... or a valley?
The figure on the left has the same orientation as the original image shown above. The figure on the right is simply flipped. When I look at these, the convex worm on the left becomes a concave valley on the right. The transverse markings suddenly look a lot more like long hills. [Note (added August 20, 2004): if that doesn't convince you, then maybe these will: anaglyphs (3D stereo images) of the worm made by Ray Girvan. When seen properly, they show the worm to be a trench.]

As far as I am concerned, this makes it pretty clear right away that Nicks' (and therefore Hoagland's) claims about this feature are completely wrong. If it's not a convex tube, then everything else he says is perforce wrong.

Whatcha Dune?

But the transverse features are still odd-looking. What are they?

Well, to me they look like sand dunes. Mars is a very sandy place, and has lots of wind. I've spent some time on beaches, and I know that wind + sand = sand dunes. In fact, Mars is littered with sand dunes. That does not necessarily mean these features are definitely sand dunes, but it's the most likely explanation.

Of course, a lot of pseudoscientists are saying these features cannot be dunes. Nicks says this in his page on Hoagland's site. On that page, he actually says he tries to be fair, and includes comments from someone saying that these are dunes. Nicks then dismisses that, saying that the winds could not possibly follow along the winding formation. But he's saying that because he thinks it's raised above the surface, convex, and not a channel. Sure, if that feature were a long windy worm coming up out of the surface, no wind could blow along it. But it's not a worm, it's a carved depression in the surface. Winds can easily flow into and down such a channel, following the winding, meandering depression. That would naturally form dunes.


crater on Mars with dune ridges On the left is another region of Mars called Gorgonum Chaos, which is a very cool name (click on the image to see it in much higher resolution). There are gullies all through this region, and they are consistent with flowing water. At the bottom appear to be more entrained dunes. The channel in which they sit is much more clearly a channel, and not a raised tube! So it looks like Mars can make features like this in channels. It's not a stretch at all to see that the same thing is happening in the valley claimed to be a giant worm. In fact, it can happen on crater floors, too, so it appears to be a fairly common feature on dusty, sandy Mars.

Not that this has stopped Hoagland, of course. On his website, in a page about the Face, he mentions this "worm" again, and says:

This is how you get the simplistic (and scientifically absurd) "sand dunes" argument when geologists are confronted by true anomalies like the "Glass Tunnels of Mars"

It's not simplistic, it's simple. Ironically, Hoagland is complaining that scientists tend to cling to ideas. Yet he is the one clinging to this being a convex feature, when it just ain't. So his whole premise is wrong from the very start.

I feel that I should also mention that there is another explanation for these features. To me, they look like ridges you get in stream beds. As water flows, it naturally generates ridges like these, similar to the annoying ridges you get in dirt roads that make your car vibrate when you drive over them. I am not saying this is more or less likely than the ridges being dunes, but it is an alternate explanation. I'm not a geologist, so I cannot say one way or the other. Maybe I'll suggest it to one of the Mars scientists, and see what they say. It's better than idly speculating, and is far more likely to yield better results.

Pane in the Glass

What about the glassy appearance of the "worm"? Nicks makes this point a few times in his writing, and other pseudoscience websites have talked about this as well. There are some bright features that look like sunglints, reflections of off a shiny object. But there is another explanation. red worm at night, Hoagland's delight In digital images, the contrast in the image has to be chosen. Someone turning the computer bits into a displayed image has to pick the brightest thing to display as white. Anything brighter than that will appear to be that same white. So if you have a feature in an image that is a little bit brighter than the surface around it, and you set it to look white, then it will look shiny to your eye. It isn't shiny; it's just a wee bit brighter.

I think that is the case here as well. I took the image and played with it just a bit in Photoshop. I made the image red, and changed the contrast a little. Suddenly, the "glassy" appearance is gone, and it looks more like what it really is: a long winding channel with ridges. This in itself shows that the interpretation of glassiness depends on how the image is displayed, and not necessarily on any intrinsic shininess of the feature.

Conclusion

So what have I shown? Let's be clear:

1) This is not a raised tube, like a worm on the ground, but a channel. It's concave, not convex.
2) The ridges are in fact ridges, and not ribs or etchings. They are most likely sand dunes entrained by aerodynamic forces (that is, wind).
3) The glassiness is another illusion, created by the contrast level in the image.
4) This object, far from being inexplicable, is actually explainable as a gully perhaps carved by water flow. The ridges are wind-entrained dunes or possibly more solid erosion features from flowing water.

So what we have here is yet another breathless claim by Hoagland and his team which, when you think more carefully about it, is grossly exaggerated at best. This isn't the fossil of some giant glass worm. It's even more remarkable, in my opinion: it's evidence that water once flowed on an alien planet. That is a fossil record of far greater interest.

I've said it before and I'll say it again: the Universe is an incredible place, fantastic enough that we don't have to make up nonsense about it.



©2008 Phil Plait. All Rights Reserved.

This page last modified Saturday, 05-Mar-2011 18:03:18 UTC


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