| Introduction:
Under the general category of the "quest for
life" on Mars a search for possible remnants of an intelligent prior
habitation cannot be reasonably excluded. As established by Freitas and
Valdes1, a Search for Extraterrestrial Artifacts (SETA) is a relevant field
of inquiry, especially in light of NASA plans to consider long term human
habitation of Mars. Recent release of Mars Global Surveyor images to the
Internet has revealed a number of unusual features that do not seem to
adhere to established geologic mechanisms. When compared to terrestrial
satellite photography at comparable resolutions, at least two specific types
of features bear a stronger resemblance to architectural structures than to
any accepted natural geologic process. These features are preferentially
found close to, but are not confined to, canyon walls near the line of
dichotomy on the Martian surface, and along the margins and within broad
planes of former sea beds. A third type of feature has been found on a large
northern latitude caldera (and is similar to other features found in planar
and mountainous areas). It shows a regular, geometric pattern similar to a
terrestrial city as viewed from orbit. Various possible geo-logic
explanations, such as fluvial erosion, wind sculpting, frost wedging and
volcanic flows, are considered but seem inadequate to explain observable
features. A tentative model is proposed with regard to the possible relative
age of these features, working within assumptions made concerning the dating
of catastrophic events in Mars Ancient History. Finally, recommendations are
made for the best candidate sites for lander and rover exploration with an
eye toward detailed exploration of these anomalies, as well as establishing
the most desirable location for a permanent, self-sufficient human base on
Mars. The three specific types of features will be examined in detail.
Images provided within the abstract are for pre-view. Larger, full
resolution images are included in the text.
Feature Type 1: An example of the first type of
anomalous feature can be seen on Mars Orbiter Cam-era image MO4-002912, a
narrow angle image taken in the Mare Acidalium region. This region is
considered a probable location of an ancient ocean3. The image, (Fig.1)
taken with a resolution of 3.07 meters per pixel, shows a number of large
plates with a rift between them. Inside the rifts are regularly spaced
brightly colored parallel features. In some parts of the image, the stripes
or arches are mostly buried, but in other portions they are almost fully
exposed. The "arches" are solid, individual features that stand
out from the
background by their shape, regularity and albedo
properties, which imply they are composed of a different material than the
surrounding terrain.

Fig.1 M04-00291
One section of the rift contains what appears to be
coherent, semi-translucent tubular structure, of which the
"arches" are a structural component. The edge of the tube can be
clearly defined against the darker background material, and the arches are
cylindrical in shape and follow the contour of the "tube." The
translucent-reflective quality of the "tube" is reinforced by a
specular reflection off an exposed portion of the object, which is in phase
with the Orbiter camera. Fluvial processes would not preferentially produce
parallel arch-like features, especially ones that are 90°
to the projected flow of water through the channel. They further would not
be restricted to the channel itself. Likewise, wind
erosion, even if confined to the rifts or channels, are not likely to
produce parallel features with such regular spacing or sharply defined
cylindrical shapes. Sand dunes on Mars display similar characteristics as
those on Earth. To ascribe these features to sand dune-like processes
requires ignoring the 3-D shape, spacing and extreme regularity of the form.
Feature Type 2: The second type of anomalous
feature is |
found most commonly along canyon
walls or floors. Images taken of the Valles Marineris system and along other
canyon walls (like Ares Vallis – image FHA00818 – Fig. 2) reveal a
tiered or "stepped" structure. Anomalous features are
distinguished by a repetitive pattern of exposed geometric cellular structure
in the vertical walls and regular, cylindrical "tubing" on the
tapered slope faces.

Fig. 2 FHA00818
The tubes themselves (image FHA00818,
close-up-- Fig. 3) have a coherent structure and seem to emerge from the
valley wall at right angles to the proposed channel flow. They then extend
under the soil, implying they are the exposed portions of a larger network.
The tubes bear a strong resemblance to terrestrial plumbing or structural
"rebar."
These patterns repeat over and over in
several visible layers in the image. Again, conventional volcanic, wind or
liquid processes seem inadequate to explain these features.

Fig. 3 FHA00818
Feature Type 3: The third type of
anomaly is a set of large block like formations on the Alba Patera Caldera
(image M02-00351 -- Fig. 4). The blocks appear to be distributed in a highly
organized fashion, and appear comparable to a terrestrial cityscape at
equivalent (1.5 meters per pixel) resolution. Specifically defined objects
range in size from typical suburban housing to roughly the size of a small
football stadium or warehouse. The blocks extend essentially the entire
length of the 7km image, with some sections buried under sand or debris.
Even so, the same rectilinear pattern can be seen beneath the sand. Although
a well-developed high-angle joint set could provide such a rectilinear
pattern, that explanation seems lacking for the following reason. Joint sets
are a series of cracks, or openings, whereas the subject features display
positive relief. The joints would have had to be filled in with more
resistant materials and then the surrounding materials eroded to provide the
observable relief. Not impossible, but also not very likely.

Fig. 4 M02-00351
|