- On the left: An electrical discharge to a
negatively charged surface, recorded on a photographic plate. On the right:
A Martian "spider."
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- The mysterious "spiders" on Mars show all of
the expected features of an electric discharge in its classic form as a
Lichtenberg figure.
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- In a previous picture of the day, we noted the presence
of hundreds of fascinating and bizarre formations called "spiders"
at the south pole of Mars. We also noted that since the discovery of these
formations a few years ago -- and despite the best efforts of planetary
scientists -- they have evaded scientific explanation.
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- We did, however, draw a comparison with the "arachnoids"
on Venus -- overlying "spidery" formations stretching around
the planet's equator.
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- In an earlier TPOD on the Venusian arachnoids, we drew
attention to an electrical formation called a "Lichtenberg figure"
(above image on the left). In 1777, the German scientist Christoph Lichtenberg
discovered that dust settling on a cake of non-conducting resin, when subjected
to an electric spark, produced starlike patterns. Later, other pioneers
found that these Lichtenberg Figures could be recorded directly on film
as a two dimensional photograph of discharge streamers. The positive and
negative surfaces in a discharge produce quite different formations.
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- If planetary scientists will consider the role of electricity
in solar system history, Lichtenberg figures will become an important diagnostic
tool. The paths of cosmic discharges across planetary surfaces will account
for many features erroneously attributed to erosion by flowing liquids
or to rifting of the surface by internal stresses. Lichtenberg figures
in three-dimensions may provide insights into the morphology of mountain
ranges, ridges, and gullies such as the arachnoids on Venus, the great
crater Aristarchus on the Moon and numerous counterparts on other rocky
bodies. This would include the so-called "drainage channels"
on Saturn's moon Titan.
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- Interestingly, it appears that none of the prolific discussions
of the Martian spiders includes the word "Lichtenberg," or the
word "electric," despite the bafflement of researchers. If nothing
else, the absence of such discussion can only underscore the narrowing
of vision in the twentieth century, as the theoretical sciences enshrined
the electrically sterile universe.
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- In electrical terms, it is probably not a coincidence
that the Lichtenberg figures are concentrated in a polar region, though
the specific type of scarring of the Martian south pole needs to be explored.
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- The unique branching pattern of the "spiders,"
called Fibonacci branching, is in fact precisely matched by Lichtenberg
figures. While some have suggested that the "spiders" are dendritic
drainage channels, both the Lichtenberg patterns and the "spiders"
radiate from a center, making the distinction between such patterns and
drainage channels obvious.
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- Like the "spiders," the branching of a Lichtenberg
figure will be largely indifferent to topography. And it is only to be
expected that the ravines of such formations would not follow terrain in
the fashion of flowing liquid.
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- Strictly speaking, the suggestion of one investigator
that the spiders are "unlike anything we have on Earth," is not
correct. We have placed here a picture of the pattern left by a lightning
strike on a golf course. Decades ago, it was engineer Ralph Juergens who
cited this pattern of a lightning blast in connection with the morphology
of Aristarchus on the Moon.
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- We note as well that the electrical explanation also
accounts for the presence of burnt soil in virtually every instance observed
-- a common feature of discharge scarring.
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- In other words, the electrical interpretation removes
each and every difficulty planetary scientists have faced in studying the
Martian "spiders." But there is more to the mystery, and in our
Picture of the Day for July 28, we will take up the remaining questions.
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