Rough Notes:
Credit: NASA
The lunar “sinuous rille”, Schroeter’s Valley.
Mar 15, 2006
The Moon and Its RillesPlanetary scientists describe it as a stupendous channel cut by flowing lava. But on closer examination, Schroeter’s Valley and its many counterparts on the Moon refute all attempts to categorize them in such terms.
The long, winding channel pictured above is the most prominent “sinuous rille” on the lunar surface—160 kilometers long and up to 10 kilometers wide—large enough to be clearly visible in Earth-based telescopes. It is also up to 1300 meters deep—a profound contrast to any observed effect of flowing lava on Earth.
Long prior to the space age, Schroeter’s Valley was the subject of many speculations. But crucial details were unknown until the Apollo lunar exploration missions in the late 60s and early 70s, when orbiting craft enabled astronauts to take high-resolution pictures of the lunar surface. The photographs in the composite shown here were taken from the Endeavour Command Module of Apollo 15.
The seven frames look approximately south, revealing the crater called “Cobra Head” at the upper left, from which emerges a winding path that narrows until it disappears on the right. Only the edge of the crater Herodotus is seen at the top of the composite. (An image of Herodotus can be seen along with the famous crater Aristarchus in our March 10 Picture of the Day.
Sinuous rilles are defined as long, winding valleys, usually with steep walls and often emerging from a crater. Of these phenomena, the Moon presents countless examples at all scales. Two instances will be seen in the lower portion of our March 10 picture.
Early speculations based on telescopic observation envisioned “cracks” on the lunar surface. Then the astronomer William Pickering suggested flowing water. A series of other speculations followed, most of them excluded by the findings of the Apollo missions, until planetary scientists eventually settled on flowing lava as the agent. The “standard theory” today states that sinuous rilles were created by lava either flowing across the surface or beneath the ground to form a “lava tube”, portions of which eventually collapsed.
A considerably larger version of the above picture can be seen here, and unless you are already certain that such formations are well understood by planetary scientists, it is worth the look. The enigmas and contradictions of standard theory lie in details impossible to deny.
Both the width and length of the Schroeter’s Valley far exceed anything ever accomplished by lava on Earth. But the reverse should be expected. On the Earth, the atmosphere is insulating, allowing lava to retain its heat. In the vacuum of space, heat will be much more rapidly radiated away. On Earth, as lava flows for long distances (counted at most in a few tens of kilometers, not hundreds), the cooling at the surface causes a “roof” to form. It may then continue to flow as a “tube” beneath the surface. That is the only way the lava tube can achieve these comparatively modest lengths.
In an earlier Picture of the Day we showed the longest terrestrial example of a lava tube on Earth, associated with Barker’s Cave in Australia. It is 35 kilometers long and only about 35 meters in height. The contrast to the much larger lunar rilles could not be more stark And the only reason the Barker’s Cave lava tube could achieve its length is that, when the insulating crust was formed, the lava was able to retain its heat and continue flowing beneath the surface. No such event occurred in the case of Schroeter’s Valley: It would be impossible to sustain a kilometers-wide roof of rock; and there is no evidence of either a roof or of rubble from a roof’s collapse.
The moon has only about one sixth the gravity of the Earth, and it is gravity that gives flowing liquid its velocity, its erosive force and (most emphatically in the case of heated and melted rock) its ability to cover distance. Yet lunar rilles extend up to 300 kilometers—almost nine times the length of the “record breaker” on Earth.
The walls of Schröeter’s Valley are both steep and deep. But where did all of the lava go? A short-lived channel of water might narrow to a termination point without any overflow or outflow—it could simply be absorbed into the ground or evaporate into space. But flowing lava eating away surface material to cut a deep channel would have to show up somewhere. We should see either breeches in the deep walls or evidence of abundant outflow. But instead, the channel simply dwindles until it disappears. In considering the picture above, it is essential that one realize what planetary scientists themselves acknowledge: The rille did not create the maria in which it sits. It cuts through the pre-existing maria. It is as if the material that once occupied the channel simply disappeared.
The “flowing lava” seems to have possessed many remarkable features. Even as it cut so deep (nothing comparable will be seen in any lava flow on Earth—not even at the much smaller scale of terrestial lava flows), this rapidly moving, molten rock, could make turns up to 90 degrees without affecting the “bends in the river” in any way. Neither the extreme sinuosity nor the parallelism of the rille walls conforms to the behavior of lava erosion.
Consider, for example, the sharply pointed prominence in the most emphatic change of direction about a third of the way down the rille from Cobra head. If the lava had the power to create such vertical cliffs—up to 1300 meters deep—how did that sharp prominence survive?
Curiously, the "flow" of rilles on other worlds isn't limited to "downhill" like lava and water-carved channels on Earth. All fluid-erosion theories have chosen to ignore that the apparent mouth of the “stream” is on high ground, and the narrowest part of the channel is on lower ground. The situation should be exactly reversed. As an erosion channel lengthens, more and more spoil must be carried by the eroding fluid, and the channel must grow wider to accommodate the load. The cross-sectional area of any fluid stream must remain constant. Where it is deep it must be narrow, where it is shallow it must be wide. However, rilles do not conform to this rule. The famous Hadley's Rille, amongst others, simply disappears for a short interval, then reappears. Other rilles travel both up and down across considerable distances. The most extraordinary example is the Baltis Vallis on Venus, which rises and falls dozens of times, with some two kilometers separating its high and low points along its 6,800 kilometer length.
Once again, it is the things barely noticed, or forgotten, that provide the most telling clues. Within the meandering channel of Schroeter’s Valley is a much more narrow secondary rille. While planetary scientists are well aware of this rille-within-a-rille, almost nothing is said about its defining feature—a chain of small craters running virtually the entire length of the rille. Yet this feature is not uncommon. A nearby rille, Rima Prinz I reveals the same “preposterous” characteristic.
As a rule, the lunar rilles are much more heavily cratered than the surrounding maria, yet by their very presence on the maria they must be younger. Standard dating by “crater count” becomes preposterous. But what is the meaning of this non-random concentrations of craters along the rille’s paths?
The inseparable link between crater formation and rille formation—though substantiated on planets and moons throughout the solar system—becomes highly confused in standard treatments of the subject. Nevertheless, a unified answer has been available for decades, and the credibility of science may, in fact, depend on it.
Coming March 17: The Rilles Are Electric
Credit: NASA
Hadley Rille on the moon, a long meandering channel, spans some 125 kilometers
(75 miles). On the right, a close-up look at a small section of Hadley.
Mar 17, 2006
The Moon and Its Rilles (2)
The Rilles Are ElectricThe surface of the moon is replete with long channels or grooves that continue to create unsolved puzzles and contradictions for geologists. Every traditional theory, when tested against the photographic evidence, has failed.
It has now been more than thirty years since the Apollo missions produced voluminous and compelling images of the lunar surface, and it is clear that theory has not kept pace with the unanswered questions.
To make our point, we have emphasized the most prominent lunar features, sufficiently documented photographically to place certain details beyond doubt. We considered the most famous lunar crater Tycho. We considered the moon’s most prominent crater, Aristarchus. We also looked at the spectacular Schroeter’s Valley, a “sinuous rille” with many lesser counterparts lying on the lunar maria.
Another channel that gained much attention during the Apollo missions is Hadley Rille (pictured above), explored by the Apollo 15 astronauts in 1971. The channel winds across some 125 kilometers (75 miles) of lunar maria. It is almost 400 meters deep (1300 feet, or one quarter mile) in places, and almost 1500 meters (one mile) wide at its widest point. Planetary scientists often say that it was formed by molten lava, and they draw comparisons to lava channels in Hawaii. But the differences between the two are so profound as to render such comparisons meaningless.
Many have suggested that Hadley is a “collapsed lava tube”, something much different from an empty surface channel of lava. As flowing lava cools, it will begin to develop a crust, and eventually a stationary “roof” may form over it. A lava tube has the advantage that it enables lava to retain its heat as it flows underground, thereby covering greater distance and collecting less debris from surface cooling. The flowing lava can produce relatively continuous and smooth walls, while a surface channel of lava, because it is continually creating its own obstructions by cooling, with subsequent overflow, will typically meander chaotically across its own debris field. Hadley does not show this appearance at all. (Compare the lava rivers here and here.
On Earth we know that the collapse of lava tube roofs is not uncommon, and the area collapsed will be a rubble-filled depression. When the European Space Agency’s Smart 1 spacecraft took an image of Hadley, the popular science website Universe Today reportedthat Hadley is “probably a collapsed lava tube”.
But no lava tube on Earth comes close to such dimensions, and that is only the beginning of the problem. The rubble left from a collapsed lava roof is impossible to miss. And we’ve seen enough of Hadley in high resolution to categorically exclude the lava tube interpretation. As shown by the close-up of a section of Hadley above (right), there is norubble, no collapsed roof. Hadley is an empty, sharply-cut channel. Whatever once lay within the cavernous depths of Hadley is no longer there.
In recent years some theorists have drifted back toward the idea of flowing rivers of lava on the lunar surface. But rivers of lava do not produce a narrow secondary rille constituted from a stream of craters along the length of the larger rille (e.g., Schroeter’s Valley). Over comparatively short distances and times, rivers of lava produce obstructing cooled material and overflow their banks to produce layers of oozing material that freezes in place and whose source is obvious. They repeatedly change course, and undercut the surface along the walls of new pathways, leaving in their wake a vivid display of their erratic behavior. (See pictures noted above). Hadley reveals no such behavior, retaining consistent width over great distances, with parallel sides, while lava rivers show just the reverse. Hadley reveals no explicit overflow or outflow. It is just an empty channel that, enigmatically, grows more narrow as it meanders across a relatively flat valley floor.
Significantly, well-qualified specialists acknowledged the definitive failure of the common theory more than thirty-five years ago. In 1970, University of Pittsburgh scientists Bruce Hapke and Benn Greenspan, based on Lunar-Orbiter photographs showing strings of craters along the floors of lunar rilles, acknowledged that such craters could not all be impact craters and must have something to do with the formation of the rilles. The direct evidence thus contradicts “those hypotheses for the origin of sinuous rilles by simple down-cutting by a moving fluid." (Report published in EOS Transactions, American Geophysical Union (51), 1970
One explanation of Hadley and other lunar rilles has yet to be considered by planetary scientists. It is the one explanation that does not produce contradictions, or conflict in any way with what we see on the moon. Engineer Ralph Juergens, who investigated a new approach to sinuous rilles, suggested in 1974 that they are the effects of “electrical discharge”. Juergens’ work, in turn, helped to inspire the lifelong explorations of today’s leading electrical theorist, Wallace Thornhill, who has taken the investigation into new areas of research opened up by more recent explorations of our planetary neighbors.
Juergens undertook a dispassionate and meticulous comparison of explanations offered for sinuous rilles. He identified the logical tests and found that prior theories discussed by planetary scientists failed. And most failed on grounds that rationally exclude the proposed explanation. (We have placed Juergens comparative chart here.
Juergens knew that an electric discharge of the magnitude implied would require an approaching charged body—and not a just a small rock but another planet or moon. “The electric field between anode and cathode [positively and negatively charged bodies] must build to an intensity great enough to "pull" electrons from the cathode by sheer force, … tearing electrons from non-conducting lunar crustal materials and in numbers sufficient to trigger an interplanetary discharge”.
The events as he envisioned them would begin with an electrical breakdown comparable to that of an exploding capacitor, as electrons begin to dissociate from their atoms to become the vehicles of an ensuing discharge. The breakdown point will be a region of maximum stress, most likely a local prominence.
“In a flash, the tiny breakdown point becomes a breakdown path propagating itself outward from the starting point, turning this way and that as the intense field at its tip probes for weaknesses in the rock strata”. Breakdown generates heat and explosively expanding plasma beneath the surface. In much the same manner that a powerful lightning strike can excavate a trench, the breakdown channel “tears hundreds of kilometers across the lunar surface at lightning speed”.
Then, as the onrushing electrons reach the local high point the resulting electric surge blasts out a large crater. At virtually the same time, more distant electrons along the breakdown path, encountering an electric field stronger than that of the underground path, “blast upward short of the main terminus, creating secondary on-channel craters at numerous points.
Juergens hypothesis was based on secure knowledge of the behavior of electric arcs. The fundamental mechanics can and have been verified in the laboratory. (See, for example, the path of the electric arc shown here, with a secondary rille or crater-stream running down the main channel).
The hypothesis can also be systematically weighed against the present library of data on the lunar surface, including the profusion of glassy spheres in Hadley Rille, and the anomalous presence of remanent magnetism. And here nothing will prove more compelling than the essential link of rille-producing activity to crater-producing activity—the very consideration that marked the failure of the lava-channel and collapsed-lava-tube hypotheses.
Coming March 20: Stardust Shatters Comet Theory (2)
Coming March 21: A Partnership of Craters and Rilles
Credit: ESA/Space-X
This SMART-1 picture of Hadley Rille offers the best look yet at a deep gash cutting across Hadley (far left).
Mar 21, 2006
The Moon and Its Rilles
A Partnership of Craters and RillesIn the history of lunar exploration, the mysterious association of craters and rilles has provoked a number of mutually contradictory hypotheses, none of which is sufficient to explain things seen in high-resolution pictures of the Moon.
In our previous looks at the lunar craters Tycho and Aristarchus, we observed that the popular “explanation” (the impact hypothesis) is contradicted by features that, in close-up photographs, invariably leap out at the critical observer.
Similarly, when we consider details of the “sinuous rilles” Schroeter’s Valley and Hadley, we discover that common teachings require things that are not there while ignoring things that are there.
The message conveyed by these prominent lunar features carries broad implications for our understanding of the lunar surface at all scales of observation. Our claim has been that theoretical assumptions in planetary science—including the most popular teachings in lunar geology—cannot withstand a critical review.
Yet there is a vantage point from which the accumulated anomalies and contradictions disappear. The electric hypothesis does not arbitrarily separate issues of crater formation from issues of rille formation. In one instance after another, we see that craters and rilles stand in a partnership that is far too pervasive to be accidental. And this convergence is predictable under the electric hypothesis.
Dominating craters on the Moon are surrounded by non-radial crater chains, irregular concentrations of smaller craters, sinuous or filamentary channels, and deep gashes—the very features seen in electrical arcing experiments and in electrical discharge machining in industrial applications. To underscore these surface patterns on the Moon, we have placed two large images of the Euler Crater region here and here. (The files are large—1.5mb and 1.8mb respectively—but they are worth the look).
The pictures show innumerable small crater concentrations, crater chains, and gashes, one form merging with another in every imaginable way. A modest number of the gashes might be mistaken for impacts at oblique angles, were it not for the repeated instances in which the gashes are constituted of overlapping craters, or are too long, or change direction—attributes that exclude “explanation-by-impact”. In this sense, an unbending adherence to the impact theory can only encourage theorists to ignore these defining features on the lunar surface.
The standard picture only grows more incoherent when we consider the numerous rilles and enigmatic channels that are conventionally “explained” as lava erosion. Why do they exhibit craters and crater chains of a sort never found in association with known remains of flowing lava? Look at the higher-resolution image we presented earlier of the Aristarchus regionhere. In the lower left of the picture is a rille that divides into twin channels, both of which end in large craters. Could this anomalous channel have been formed by flowing liquid of any kind? It is simultaneously a crater chain and a rille, confirming the point made repeatedly by the electrical theorist Wallace Thornhill: The same force that produces crater chains produces rilles.
Rilles often exhibit craters deeper or wider than the channels on which they are centered. For a good example, consider the picture of Rima Hyginus here. In many instances the larger craters centered on a rille appear at the “joints” of a meandering channel. Could they be “collapsed lava tubes,” a once-popular hypothesis? It is only necessary to look closely to see that these formations never reveal rubble from a collapsed “roof”.
Not infrequently, we also observe a secondary stream of smaller craters meandering down the rille, as we saw along the floor of Schroeter’s Valley. The electrical theorists point to analogs in both laboratory arcs and in lightning-excavated trenches. On the moon, a fascinating example is Vallis Alpes, a spectacular channel that extends some 166 kilometers, cutting across the mountain range Montes Alpes. Clearly, it was not cut by flowing liquid! See pictures here and here. Along its mid section it is about 10 kilometers wide. Meandering down the center of the flat valley floor is a narrow rille punctuated by circular craters.
Inexplicable gashes emerging from craters or converging with crater chains are ubiquitous on the lunar surface. Our picture of Hadley Rille above, recently taken by the ESA SMART-1, shows an “inexplicable” gash on the far left. The long and deep gash emerges from the narrow end of a balloon-like crater to cut across Hadley. It certainly has no explanation in standard theory, and most lunar scientists simply address it as a “gash” and go on to something they “understand”.
To put all of this in perspective, we must remember that the craters, rilles, crater chains, and gashes on the Moon can now be systematically compared to analogs on other bodies to see whether scientists have been able to forge a coherent interpretation. We find that, as the quality of the pictures has improved, the interpretations have grown increasingly fragmented and bizarre. For a telling comparison of the lunar enigmas to those presented on another body, look at the so-called “collapse pits” on the Martian “volcano” Arsia Mons. All of the lunar enigmas are there in one place—craters, crater chains, gashes, and rilles—except that here the stunning clarity of the pictures gives common sense a distinct advantage. Are these formations the result of “surface collapse”, or has material been cleanly removed from the surface by a force unknown to planetary scientists? In a contest with the inertia of prior belief, common sense will surely win out in the end.