Path: news.ucalgary.ca!news From: macrae@geo.ucalgary.ca (Andrew MacRae) Newsgroups: talk.origins Subject: Re: VELIKOVSKY: astronomic evidence/Venus- new planet (LONG!!!) Date: 12 May 1995 07:49:39 GMT Organization: The University of Calgary Lines: 2192 Message-ID: <3ov3uj$pm4@ds2.acs.ucalgary.ca> References: Reply-To: macrae@geo.ucalgary.ca NNTP-Posting-Host: pandora.geo.ucalgary.ca In article walter@netcom.com (Walter Alter) writes: > > > THE SURFACE OF VENUS A NEWBORN B ABE > > by > Charles Ginenthal > > > Strange. when you think about it. how a lack of information so often > grows by leaps and bounds into a belief that has no scientific basis > but becomes "accepted fact" simply because enough people want to > believe it. Few things irk men of science (and they aren't all that .. Ginenthal does not know how right he is :-) .. > In 1950, Immanuel Velikovsky claimed that the testimony of ancient > peoples from all parts of the globe described Venus as a giant, > brilliant comet. Based on Velikovsky,s analysis of this data he drew the > conclusion that Venus was a newborn planet in the early cool-down stage > of its development. Therefore, if his understanding of the evidence was > correct then Venus, surface should exhibit all the conditions of a world > that was very recently molten and is most likely still volcanic and > geologically active. Keep that last sentence in mind. Note: This was intended for the moderated alt.catastrophism forum, so, as an experiment, if Ted, Walter, or another Velikovsky supporter decides to response, I encourage you to comply with the proposed moderation policy. I am *NOT* interested in the usual insults from Ted, for example. If you have no comment to make that would pass the proposed alt.catastrophism policy, then I see no point in making it, but go ahead and be counterproductive if you really want to be. As always, corrections are welcome. ======begin pre-prepared posting we were hoping to send to alt.catastrophism, but the group *still* has not shown up, so here goes anyway...====== This article is a discusion between James Acker and Andrew MacRae of the geological and geochemical evidence from Venus, as presented in an article by Charles Ginenthal. The style is a bit unusual, because we passed comments back and forth a few times, so it reads like a conversation. The original article was posted by Ted Holden [note: and now re-posted by Walter Alter]. Comments can be directed to either James or Andrew. James Acker -- jgacker@neptune.gsfc.nasa.gov Andrew MacRae -- macrae@geo.ucalgary.ca =========== |THE SURFACE OF VENUS A NEWBORN BABE |by |Charles Ginenthal [del] |Nowhere was it ever suggested by establishment scientists |that Venus would be found to be a volcanic cauldron covered |by immense lava flows. In fact, as recent as 1989, Isaac |Asimov, the late popular science writer, remarked: |For years astronomers had believed that Venus was a |geologically dead place. Although quakes, volcanoes and |other activity surely wracked the planet at one time. it |seemed certain that Venus was quiet today.3 [3 I. Asimov, "The Unknown Solar System", Discover (Oct. 1989). p. 40.] ** MACRAE: I do not know where Asimov got his information, but he was wrong, based on the quote Ginenthal has provided. Evidence for the presence of volcanoes (whether inactive or active was not known) had existed for decades prior to 1989, and hypotheses of current activity were being considered. In fact, it was generally thought Venus would be much like Earth, geologically speaking, and would therefore be geologically active on a similar scale, possibly even with plate tectonics. Possible volcanoes and impact structures had been identified even in the 1970s as a result of Earth-based radar imagery, but the interpretation was ambiguous. (The possible presence of volcanoes, on the basis of radar data from the 1970s, is *even* mentioned in Glass, 1982 (e.g., p.316-320, and fig.9.10-9.12) -- one of the references *Ginenthal* cites.) People certainly *considered* the possibility Venus could be geologically active. Can Ginenthal cite some other earlier scientific literature (rather than a magazine article) where a claim like Asimov's is made? |Therefore, if Velikovsky's analysis of the ancient testimony |is correct the observations by the Magellan spacecraft |should not only contradict the previous models of the |Venusian surface but should also show overwhelming evidence |of recent stupendous volcanism on a surface that appears to ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ** MACRAE: And continuing on a huge scale. Volcanism on that scale can not shut down in a few thousand years. |be pristine. One of the first indications of this excessive |volcanism was presented in May 1990 in the Journal of |Geophysical Research which analyzed the sulfur content of |the Venusian clouds. There Na Y. Chan et al. state: |Results of recent International Ultraviolet Explorer (IUE) |observations of Venus made on January 20, 1987, and April 2 |and 3, 1988. along with a re-analysis of the 1979 |observations...are presented. The observations indicate that |the amount of sulfur dioxide at the cloud tops of Venus |declined by a factor of 8~4 from 380 +/- 70 ppb [parts per |billion] to 50 +/- ?0 ppb in 1987 and 1988. 4 [4 N. Chan. L. Esposito, T. Skinner. "International Ultraviolet Explorer Observations of Venus SO2 and SO", J. Geophys. Res. 95 (May 20,1990). p. 7485.] |One of the researchers of this phenomenon, Larry Esposito |from the University of Boulder Colorado [sic], elaborated on |this decrease of SO2 and SO two months later in Astronomy: |Pioneer Venus has continued to monitor these constituents |above the clouds. Over the years a remarkable discovery has |emerged: both sulfur dioxide and the haze have been |gradually disappearing. By now only about 10 percent of the |1978 amount remains. This disappearance has also been |confirmed by the Earth-orbiting International Ultraviolet |Explorer between 1979 and 1987 and other Earth-based |observations. The haze and the sulfur dioxide are now |approaching their pre-l978 values. Analysis of recent |Earth-based radio observations by Paul Steffes and his |colleagues show less sulfur dioxide below the clouds than |was measured by Pioneer Venus and the Venera landers. which |is also consistent with the decrease of sulfur dioxide. |Inclusive Earth-based data show that a similar phenomenon |may also have occurred in the late 1950s. |The best explanation right now for the decrease is that from |time to time major volcanic eruptions inject sulfur dioxide ^^^^^^^^^^^^ |high altitudes. The haze comes from particles of sulfuric |acid. which is created by the action of sunlight on sulfur |dioxide. Being heavy the particles gradually fall out of |the upper atmosphere, letting conditions up there return to |normal between eruptions. ** MACRAE: Decades between eruptions does not sound like "stupendous volcanism". On Earth, there are an average of 10-15 volcanoes actively erupting at any instant. ** ACKER: Mt. Pinatubo was either the second-largest or largest eruption in the 20th century, and did inject SO2 into the upper atmosphere. (The other contender was Katmai, 1912.) Two "stupendous" eruption in 100 years. Well, then Venus is (based solely on this datum) only as active as Earth. Other data indicates it is less active. [del] |Measurements by the Pioneer Venus Orbiter show that the |amount of sulfur dioxide present near the cloud tops |declined from approximately l00 parts per billion (ppb) in |1978 to about 10 ppb in 1986. There is also fragmentary |evidence of similar increases and decreases at earlier |times. Such fluctuations might be due to episodic injections |of SO2 high in the atmosphere by powerful volcanic |explosions.6 |David Morrison and Tobias Owen put the case even more |strongly: |Observations over the past twenty years have indicated that |large fluctuations occur in the concentration of sulfur |dioxide (SO2) in the atmosphere of Venus above the clouds. |When these observations are combined with indications of |volcanic topography and lightning discharges for possible |volcanism, the case for erupting volcanoes on Venus becomes |rather strong.7 |[7 D. Morrison. T. Owen, The Planetary System (New York, |1988), p. 235.] |This appears to be indirect evidence that at least twice in |the 1950s and 1970s there were major volcanic eruptions on |Venus, surface. There are, of course, questions and |objections related to this analysis; nevertheless, the |Magellan spacecraft may have already observed explosive |volcanism. ** ACKER: Only possible evidence of an volcanic eruption, not an eruption in progress. ** MACRAE: There has been no direct observation of the products of current eruptions by the Magellan probe, and *nothing* on the scale that is being proposed by Ginenthal, which should be *very* obvious. An eruption in the 1970s and nothing comparable since does not seem very active either, if volcanism is the explanation. ** ACKER: Analysis of Magellan data indicates one possibly recent (within ~100 years) lava flow in the vicinity of Maat Mons. [Robinson, C.A.; Wood, J.A. Recent volcanic activity of Venus: evidence from radiothermal emissivity measurements. Icarus, March 1993, vol.102, (no.1):26-39.] ** MACRAE: Differences in radar reflectivity (as this example is) seem like rather weak evidence, particularly when flow composition and surface characteristics can easily change from eruption to eruption, and the constraints on the surface properties of Venus are relatively limited, and are not necessarily analogous (probably are not) to flow weathering patterns on Earth. Even if this flow is recent, where is the "stupendous volcanism"? One possible flow is it? |In the December 1990 issue of Scientific American appears a |photograph made by Magellan which appears to exhibit |exploded material from one of its craters. The caption |accompanying the picture states: |Explosive volcanism may be responsible for the radar-bright |deposit that extends roughly 10 kilometers from the |kilometer-wide volcanic crater at the center of the image. |The etched pattern of the surrounding plains becomes more |obscure closer to the crater, which indicates that the |deposit is thickest near the crater. The shape of |the deposit suggests that local winds either carried the |plume southward or else gradually eroded away the plume |material except for that part located in the volcano's wind |shadow. ** MACRAE: This deposit could have formed a significant time in the past, and is not an indication of a recent eruption. It is an indication of an explosive eruption that produced pyroclastics at *some* time. If the plume was observed to change during the multiple passes of Magellan, then it might mean something. |These bits of information, though consistent with volcanic |activity, need to be corroborated by other information that |will give a more comprehensive picture of a planetary |surface formed by massive volcanic processes. ** MACRAE: Evidence for the *current* eruption of volcanoes on a "massive" scale should be obvious in the multiple passes of the Magellan probe. Very little change (** ACKER: if any) was observed. Formed by "massive volcanic processes", yes. Being formed *now* by "massive volcanic processes", no. |In this respect, we turn our attention to another body in ^^^^^^^ |the solar system that is in the throes of massive, violent, ^^ **MACRAE: The above sentence should leave out the "another" part. It is still not demonstrated there is current volcanic activity on Venus, let alone "massive, violent, ongoing activity". The association implied in this sentence is misleading. |ongoing volcanism and exhibits several notable features |related to this Venusian phenomenon. That body is Io, the |inner Galilean satellite of Jupiter. As Io orbits around |Jupiter it is constantly being distorted in shape |by its tidal interactions with the very massive Jupiter and |its three outer Galilean satellites. As Io is distorted and |flexed, like the action produced by bending a spoon, |enormous heat is generated producing volcanism. Therefore, |Io is molten at a relatively low depth of its surface and |its thin crust is floating on an ocean of molten magma. The |amount of heat emitted by Io, according to David |Momson (a member of the imaging science team for the Voyager |spacecraft) shows: "[An] internal heat source estimated at |10^14 W- needed to drive this volcanism is two to three |orders of magnitude [100 to 1000 times] greater than that |expected from normal radionucleides..."8 [8 D. Momson, "The Satellites of Jupiter and Saturn," Ann. Rev. of Astron & Astrophysics 20 (1984), p. 480.] ** MACRAE: Yes. As an analogy of what Ginenthal's model predicts, Io is quite good. I agree. |Io is the most volcanic body in the solar system. According |to Billy Glass: The volcanic eruptions [on Io] appear to be |comparable in intensity to the greatest terrestrial |eruptions which are rare on the Earth. Io appears to be |volcanically more active than the Earth. This has made |mapping Io difficult because the active regions undergo |radical changes in short periods of time. In the four month |interval between Voyager 1 and Voyager 2. for example. one |of the largest (200 km diameter) [122 miles] eruptive |centers on Io known as Prometheus was transformed from a |heart shaped feature to a circular one.9 [9 B. Glass. Introduction to Planetary Geology (New York, 1982). p. 364.] ** MACRAE: Exactly. Massive, obvious changes in surface features at a scale easily detected by Voyager over a short time (only 4 months). ** ACKER: Just to clarify, between the Voyager 1 and 2 encounters. And note that the Voyagers also observed active volcanism on Io. ** MACRAE: Yes, but to be fair, the plumes were detected in optical wavelengths, and a) the higher gravity and much thicker atmosphere of Venus would make such huge plumes (1000km wide, 280km high) unlikely, and b) Magellen probably could not easily detect them anyway (although any modification of surface features by the deposition from the plumes *should* have been obvious). |Hence, if Venus was an incandescent body 3500 years ago and |then cooled to the point where it became molten before it |arrived at its present state, it should exhibit a topography |quite similar to that of Io. ** ACKER: And Venus does not. [MACRAE: It has high mountains, (some volcanic cones, some compressive mountain belts), rifts, and a surface relief of several kilometres.] Venus has very few impact craters that are affected by volcanic processes [MACRAE: And a total of about 900 impact craters, most >10km in diameter]. Io has no visible impact craters, due to the ongoing volcanic activity. ** MACRAE: And its surface features are continually changing. Io *is* a good analogy for what would be expected of the surface of Venus if Ginenthal's model were correct. The problem is, the surface of Venus bears only a superficial resemblance to Io, because Venus appears to be much, much less active. |In essence the volcanic forms observed on Io should |generally be representative of the surface features seen on |Venus. There should, of course be differences between the |bodies because Io's temperature is not decreasing whereas we |presume that Venus' temperature is. Furthermore, there will |be differences in the materials each body contains which |will also affect the appearance of their surfaces. |Before comparing Io and Venus we wish to point out that many |of the volcanic craters on Io do give the appearance of |impact craters. According to Carr et al.: |Calderas occur in every region of Io so far photographed. |They are generally recognizable by their strong resemblance |to terrestrial and Martian calderas. In many cases no |relief can be detected and a caldera is inferred from the |presence of a dark circular feature. Over 5% of the Ionian |surface seems to be part of a caldera, either dormant or |active. Where relief is discernible the calderas are |recognized as rimless depressions with steep, inward-facing |scarps and relatively flat floors.l0 ** ACKER: Ginenthal pays no attention to what is said here! The calderas are CALDERAS, and not cited as being similar to craters. Note that the calderas are _rimless_ depressions. Impact craters have rims, and many times a central "rebound" peak. (Example: Moon's Copernicus crater.) ** MACRAE: Many impact craters on Venus also have clear ejecta patterns overlying the surrounding lava plains (and therefore clearly younger), and the larger ones even have the square-root of 2 radius relationship of fault scarps seen in many large impacts on Earth and other planetary bodies. (Melosh, H.J., 1995 (Jan. 12). Under the ringed basins. Nature, v.373, p.104-105 and references therein.). Volcanic calderas are, in practice, easily distinguishable from impact craters. Genuine volcanic calderas are known from Venus, and look completely different from the impact craters. Both impact craters and volcanic calderas are observable on Earth, and their morphology is very well understood. It is unlikely even a small fraction of identified impact craters on Venus (about 900 are known) could be misidentified volcanic calderas. |PLAINS VULCANISM |David Momson describes Io's volcanic features as follows: |Some of Io's volcanic features look a great deal like their |terrestrial counterparts: low shield-shaped constructs with |calderas at their peaks and flows of erupted matenals on |their sides. However. most of Io's calderas are not at the |tops of mountains but instead appear to be scattered amid |the plains.ll [II D.Momson. "The Enigma Called Io" Sky & Telescope (March1985), p.201.] |Io exudes its magma in this manner because it is |tremendously hot internally and has an extremely thin crust. ** MACRAE: Yes. The calderas tend to occur on the plains because the hot, thin crust of Io can not support much topography. Contrast with, for example, large volcanic cones like Hawaii (Earth) or Olympus Mons (Mars), where the emanations of the volcanic activity build a high mountainous peak that is partially supported by the stiffness of the underlying crust (which bends under the weight). |Therefore if Velikovsky was right that Venus was hot |internally just below its thin crust it too should |pour forth its magma after the fashion of Io. observations |should show evidence that lava is either presently or has |very recently been exuded from circular vents on the plains |of the Venusian surface. ** MACRAE: But Venus also has obvious, high volcanic peaks with calderas at the top and flows rolling down the sides -- i.e. like large shield volcanoes on Earth and Mars. This sort of volcanism should not occur if the crust of Venus is hot and thin like Io's. |In New Scientist we learn that radar shows lava flows on |Venus are indeed very much like those on Io: |"The flat plains of Venus consist of lava that has flowed |from the planet comparatively recently, according to latest |radar results. ** ACKER: Ginenthal skips over what "comparatively recently" means. It means, according to Venus geophysicists, within the last 500 million years. The writing, whether intentional or not, is misleading. |And an appreciable amount of the planet's heat may escape |through these lava flows. rather than through large |volcanoes and rift valleys that geologists have known for |some years. In the plains the researchers found dozens of |small vents, which oozed lava without forming volcanic |cones. The researchers say: |"The large number and wide distribution of vents in the |lowlands strongly suggest that plains volcanism is an |important aspect of surface evolution and contributed to |heat loss on Venus."l2 [12 New Scientist (Nov 4, 1989), p. 34.] ** MACRAE: Yes. Conduction of heat through a silicate rock crust is much less efficient than simply moving the magma to the surface and erupting it. But the point is whether that is *currently* occurring. |Thus, there is a basic similarity that strongly suggests |that Venus is venting its internal heat through plains |volcanism. This implies that Venus, like Io, has a thin |crust and is extremely hot not far beneath that crust. ** MACRAE: But as pointed out above, the topography *should* be more like Io. It isn't.] ** ACKER: Interestingly, the planetary resurfacing scenario, similar to flood basalt volcanism on Earth, does not rule out such features. Flood basalt areas such as the Deccan traps and Columbia River basalts in Washington State should be observed. However, the occurrence of deep impact craters on Venus, and the Magellan gravity data that post- dated this work, rule out a thin crust on the planet Venus. |THE NATURE OF IO'S AND VENUS' CRATERS ** MACRAE: There is absolutely no justification for using the term "crater" in an unqualified fashion as is done here. Ginenthal is talking about two different things: volcanic calderas on Io (there are no impact craters on Io), and volcanic calderas *and* impact craters on Venus. He did not justify the claim they have been confused on Venus, and there is practically no chance they have been. Without justification for mixing the terms in an ambiguous fashion, this can be nothing more than an attempt at obfuscation. He is even bold enough to remove the volcanic terms the authors have used and replace them with "crater", to help with the confusion. |Since Io possesses such a thin crust floating on a bed of |magma, that crust can become deformed. Io's craters [volcanic calderas] |are situated over the upwellings of the |hottest magmatic flows and, therefore, distortion of the |crust should be in evidence most strongly at these sites of |upwelling. This, indeed, has been well observed by Voyagers |1 and 2. Carr, et al., describe the crater [volcanic] |caldera shapes in this manner: "Although most [craters] [volcanic calderas] |are nearly circular, they range widely in shape; some |have scalloped walls suggesting collapse about different |centers, others have rectilinear outlines, and others have |elongate, slot-like shapes."l3 [13 M. H. Carr. H. Masursky, R.S. Strom, R. J. Temle, "Volcanic features of Io," Nature 280 (Aug. 30, 1979), p. 730.] |One of the first reports from Magellan respecting non- |circular craters on Venus was presented in the New York |Times for Sept. 18, 1990. ** MACRAE: And what about subsequent reports in the technical literature? Not important? |There it was reported that a kidney-shaped crater had been |observed. The explanation given to explain this unusually |shaped structure was that the "kidney-shaped crater appeared |unlike any other in the solar system. Perhaps an incoming |meteor broke up as it passed through the dense Venusian |atmosphere, causing several large chunks of material to |strike almost simultaneously in an irregular pattern." 14 [14 R Saunders, "Surface of venus,,, Scientific American (Dec. 1990), p~] ** MACRAE: Non-circular impact craters *are* known from other planetary bodies (Mars, the Moon, and Earth). (e.g., Schultz, P.H. and Gault, D.E., 1990. Prolonged global catastrophes from oblique impacts. IN: Sharpton, V.L. and Ward, P.D. (eds.), Global Catastrophes in Earth History: An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality. Geological Society of America, Special Paper 247, p.239-261). They are usually due to oblique impacts, and this mode of formation is quite convincing as an interpretation (they have, for example, the "butterfly shaped" ejecta pattern predicted by models). The difference with the one being cited is the closely-overlapping nature of multiple impact basins, producing a "kidney-bean" shape, and indicating the likelihood of an impactor that broke up on the way through the atmosphere, but did not separate much before impacting. *This* is the unique part, not the non- circular nature. This example is unambiguously an impact, and not a volcanic feature. Saunder's article is a 6 page "photo essay" with captions, yet Ginenthal cites it as if it were a full technical paper. It is a *SUMMARY*. You can not expect to see a detailed explanation presented, particularly given the preliminary nature of the results. Yet, practically everything Ginenthal cites for the Magellan data is either a popular magazine article, a newspaper article, or a 1-2 page summary. This is fine to get a flavour for the data, but if you want to understand the technical issues, and honestly present them, you have to get into the technical literature, of which there has been an ample amount published since Magellan results have started to come in. Why does Ginenthal avoid it? ** ACKER: Such multiple craters are indeed, and without any doubt as to identity as impacts, observed on Venus. Whether or not this particular crater was one is unknown without reference to the imagery. [MACRAE: It is. The image is very convincing. You can see the streaks of ejected material around it. They look quite different from volcanic flows.] |However, over time more and more irregular shaped craters |were observed so that the first example could no longer be |considered unique. Thus an article in Discover states, |"Even Venus, meteorite craters are intriguing. |Some have strange and irregular shapes, in puzzling contrast |to the round outline typical of most impact craters in the |solar system."5 |So far as is known only two worlds- Venus and Io exhibit [5 L. Esposito, "Does Venus Have Active Volcanos?" Astronomy (July 1990). p. 45. Actually, according to G's footnotes, this was in Astronomy, not Discover.] ** ACKER: Incorrect. There are oblique angle craters in Argentina. ** MACRAE: Worse. They are known on Mars and the Moon too (see the paper cited above). Again, the "craters" on Io are volcanic features, the non-circular features observed on other planets are clearly impacts, and most closely fit the expectations of oblique impactors. |very large numbers of misshapen craters. This again strongly ** ACKER: Only Ginenthal says "very large numbers". The article only says "some" craters. ** MACRAE: They are actually quite rare in proportion to the hundreds of known impact craters on Venus, or the thousands known on the Moon and Mars. |implies that they were created in the same way under similar |conditions. ** ACKER: While there are several multiple impact sites, there are also undoubted calderas on Venus. That Venus was volcanic at one time is not in dispute; the level of modern-day volcanism is what is being questioned. |That is, both Venus and Io are highly volcanic |and have thin crusts floating on magma: "Lunar ** ACKER: The assertion here is now known to be wrong with regard to Venus. |craters, l.e terrestrial impact craters...tend to be |circular, whereas calderas do not"l6 [16 According to J.E. Guest and R. Greeley, Geology of the Moon" (New York)1977), p. 99.] ** MACRAE: Ginenthal should attach more significance to the word "tend". While it is true that most calderas can have more elaborate shapes than circular, it is an empirical observation that the *vast* majority of impacts on Venus (or anywhere else) are circular. Ginenthal is taking the observation of a *few* impact craters with unusual shape and extrapolating to all of them. |Geophysicists have generally considered misshapen craters as |volcanic structures on the Moon and on Io. However, when |they observe misshapen craters on Venus in which nearly all |craters over 12 miles in diameter are observed to be filled |with lava and in which a percentage have lava rivers |emanating from them, the scientists have |changed their interpretation to suggest that the craters are |no longer of volcanic origin but of impact origin. ** MACRAE: Geophysicists base the distinction between impact craters and volcanic calderas on much more than a circular or non-circular shape. A fraction of impact craters on Venus have volcanic flows in association with them, but a large number do not. If Ginenthal's "thin hot crust" model is correct, almost all should have such features. Finding some craters with evidence of associated igneous activity simply means that some cratering occurred during the time of volcanic activity, or that the impact was large enough to generate impact melt (commonly observed on Earth too). ] ** ACKER: There are a few very clear craters on Venus that are impact craters with subsequent melting and lava flows. They appear morphologically dissimilar from the calderas. |If Io's [volcanic calderas - A.M.] and Venus' [impact - |A.M.] craters were, indeed, generated by similar processes |then they should also show common features other than their |non-circular shapes. ** MACRAE: Suddenly, and without explanation, a few non- circular impact craters on Venus seem to have become all "craters", or at least the only ones that need to be considered. |For example some of Venus' craters are quite deep. |Thus Dr. Gordon H. Pettengill, a leader of the Magellan |radar team, reported that the spacecraft's flrst altimeter |measurements were defining the texture of the planet's |topography. One surprise, he said, "was discovering that a |previously surveyed impact crater named Colette is more than |two miles deep-far deeper than any crater seen on the Earth |or any other planet."l7 [17 New York Times (Sept. 27, 1990), p. B4.] ** ACKER: Incorrect. Clementine has now mapped impact basins on the moon at least six miles deep. ** MACRAE: This should be evidence *against* the "hot thin crust" model. If the crater were that deep in a thin crust full of magma, it is likely to be filled with lava flows. The explanation for deep calderas on Io is the withdrawal of magma from reservoirs beneath. This produces near-vertical vertical concentric collapse scarps along the margins of the calderas. These are not observed in the Venus impact craters. |On Io, too, we find that "some calderas are several |kilometers deep..."18 [18 The New Solar System, J.K. Beatty & A. Chaikin eds., (New York,1990), p. 181.] |Moreover, there is another level of resemblance between the |[volcanic calderas - A.M.] craters of Io and Venus |that strongly suggests that Venus' craters are of volcanic |rather than impact origin. Because Io's craters are |accepted as having been produced by volcanism the outflows |of rivers of lava from them is not considered enigmatic to |the space scientists. In this regard it is reported: |One of the most striking aspects of Io's calderas is the |associated albedo patterns. The floors of most are very |dark and the low reflectivity of many is accentuated by |bright haloes around the craters. [Sulfur] rendered molten |by heat from silicate magmas...maybe the source of some of |the river like features that snake across Io's surface...The |flows from one of Io's craters are very long stretching for |hundreds of kilometers.l9 [19 The New Solar System, J.K. Beatty & A. Chaikin eds., (New York, 1990), p. 181.] |R. Stephen Saunders reports of one Venusian crater: "The |crater's flat, smooth floor hints that it has been flooded with lava.," ** ACKER: Also true of lunar maria. Not unexpected. ** MACRAE: The largest impactors often generate significant impact melt too. |Saunders exhibits photographs of Venusian craters which show |dark floors with bright halos around them ** MACRAE: This is an irrelevant comparison to Io's features. The Magellan images are *radar*, the Voyager images are *optical*. "Dark floors with bright halos around them" is a meaningless similarity because "light" and "dark" mean different things in radar versus visible light. |and then informs us that. "River-like erosion features |running from the largest crater in the image are as yet |unexplained."2l [21 R. Saunders, "The Surface of Venus," Scientific American (Dec. 1990), p. 63.] |The reason for this difficulty is, of course, that the |interpretation of these long river-like structures from the |craters suggests that the craters are not impact formations |but volcanic creations. ** MACRAE: No, it doesn't. They are interpreted as impacts because of other features, like the ejecta pattern and central peak. The co-occurrence of craters with the "river- like structures" means some of the impacts occurred in association with the volcanism. This is not unexpected. Saunders comment is in a caption a few sentences long in 1990. There was no space to consider what they were, and there was no time (as of 1990) to consider what they were. They are small structures on the image. They could be volcanic flows (as reproduced, the image is too low resolution to tell). |With respect to this long river, ** MACRAE: This is not the same structure Saunders was referring to! |Andrew Chaikin writes: |One of the most bizarre features yet identified on Venus is |a remarkably long and narrow channel that Magellan |scientists have nicknamed the river Styx. Although it is |only half a mile wide. Styx is 4,800 miles long. What could |have caused such a channel is unclear. Water, of course, is |out of the question. Flowing lava is a possibility but it |would have to have been extremely hot, thin and fluid.22 [22 A. Chaikin, "Magellan Pierces the Venusian Veil," Discover (Jan. 1992), p. 22.] ** MACRAE: The already high surface temperature of Venus would tend to allow lava to flow longer and faster. ** ACKER: It was recently suggested that these features might be carbonatite, rather than basaltic lava, a lava that is molten at much lower temperatures than basalt. At Ol Doinyo Lengai, Tanzania, the only currently active carbonatite volcano on Earth, carbonatite lava flows wander all over the caldera floor during an eruption. |One further resemblance between the [volcanic calderas ] |craters of Io and [impact craters of] Venus is their general |size or diameter. Billy Glass observed that the [volcanic |calderas] craters depressions on Io are "up to 200 km in |diameter."23 [23 B. Glass. Introduction to Planetary Geology (New York, 1982). p. 364.] |On Venus it is assumed that any crater larger than 300 km |would settle by geological flow in about one |billion years.24 [24 G. McGill et al., Venus (Tempe, 1983), pp. 95-96.] ** ACKER: All craters on [the surface of] Venus are likely less than 500 million years old. |Sulfur is the fluid suggested as being responsible for river |structures on Io. ** MACRAE: So? |However, the River Styx runs up as well as downhill. What is |clearly implied, if this feature is a flow, is that the |surface topography has shifted greatly since the flow |ceased. ** ACKER: Big deal. Surface topography in volcanic areas is always changing. Ginenthal would have us believe this was a recent change. There is no indication it was recent. ** MACRAE: Similar topographic changes can be observed for some former river courses on Earth. If anything, it means the formation of the "river like structure" had to occur long enough ago for the topography to change subsequently.] |Furthermore, Science News reports recent changes on Venus |that have been attributed to wind blow debris but a deep |regolith has not been seen anywhere on Venus and the ** ACKER: UTTERLY incorrect. Large dune fields are found in the Magellan images. Due to the radar reflectivity properties of dust and sand, they are not prominent -- but they are definitely present. [MACRAE: Although not areally extensive.] |scientist who discovered the changes also suggests that the |differences between the 1991 image and another taken months |later may stem from an actual surface change.25 [25 R. Cowan, "Magellan finds wind sculpture on Venus," Science News (March 28, 1992), p. 198.] ** MACRAE: If this subtle change was found, why wasn't evidence for the active "massive volcanism" analogous to Io?!? Blowing dunefields have nothing to do with active volcanism. |The largest craters so far observed are about 275 km in |diameter. This implies that a molten body like either Io or |possibly Venus would produce craters of this size and |smaller. This of, course, is still to be determined by the |full scale observation of Venus by Magellan. If this |evidence holds up it will again imply that Venus is molten |at shallow ** ACKER: The evidence does not hold up, and the gravity data indicates a thick (30-70 km) crust. |depth. This however, does not negate the possibility that |tidal forces on solid bodies such as the Moon |may generate larger craters such as the Mana basins. |In summarizing the information about [volcanic calderas and |impact] craters one notes that their shape, depth, size, and |bright halos around craters and dark flat centers bearing |river-like lava flows on both Io and Venus are strong |indications that volcanism is the cause of these |surface features. ** ACKER: Except in the cases of actual volcanic features, the known impact craters on Venus are unequivocally identified as impact features! |One can also add that both Io and Venus possess craters with |central peaks and craters without central peaks which can be |seen in any good collection of photographs |made of these bodies. ** MACRAE: Where? Where is that citation for the occurrence of central peaks in the "craters" of Io?] |To some extent confusion reigns in the analysis of Venus, |craters as impact structures. ** MACRAE: Ginenthal has not helped by mixing and matching terms, and changing the terms used in the literature. |Consider the problems posed by the crater known as |Cleopatra. Here Burnham points out: |Cleopatra is an impact crater surrounded by terrain that has |been extensively modified by volcanism. probably induced by |the impact...According to present thinking. if there was |enough volcanic material available close to the surface so |that it could spill out after the impact. then Maxwell [a |nearby mount] itself would have softened and slumped to a |much lower elevation. What is the answer? No one knows |yet.26 [26 Robert Burnham, Astronomy (Sept. 1991) p. 37.] ** ACKER: Hideously twisted. Maxwell Montes is a large volcano. If the area of the Cleopatra impact is a volcanic area, then impact-induced volcanism could have occurred, or subsequent flows could have affected the crater. In the August 1993 issue of _Sky and Telescope_, there is an image of Maxwell Montes and Cleopatra. Cleopatra appears as a pristine double-ring crater basin on Maxwell Montes. The pristine nature of the crater in the area of apparently high volcanic activity says one of two things: either the impact was quite recent, if Montes is reasonably active (which is not known), or Montes, despite being a volcanic edifice, is not very active, consistent with the picture of the entire planet's geophysics. ** MACRAE: The real question, in my mind, is why *all* of the impact craters on Venus do not show evidence of associated volcanism if Ginenthal's model is correct. Only a small fraction do. |In no manner at all does impact cratering explain Cleopatra. ** ACKER: Wrong. Cleopatra is an impact crater, pure and simple. Even a radial ejecta blanket is partially visible. |Rather, as is the case with most volcanic craters, a vent |made its way up to the slopes of Maxwell Montes and broke ** ACKER: A walking volcanic vent? |through the surface creating a large crater and pouring lava |over the surface. Significantly, Burnham reports that, |"All craters larger than about 20 kilometers across have ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |interiors at least partially flooded with lava."27 [italics |added]. [27 Robert Burnham, Astronomy (Sept. 1991) p. 37-38.] ** MACRAE: I.e. all *BIG* craters have some degree of infilling with lava. Considering the observation that large impacts often produce their own impact melt in significant quantities, this is not surprising.] ** ACKER: Likely the author's statements are very preliminary. The article was written in 1991, and the Magellan mapping mission was not complete. Furthermore, lava flooding on large impacts is not unexpected in any context of planetary geophysics. |From this it is quite clear that volcanism rather than |impact is the dominant cause of cratering on |Venus. ** ACKER: As now seen, this statement is very likely incorrect. There are about 900 definite impact features on Venus, and they are not confused with volcanic calderas. |PANCAKE-SHAPED DOMES AND OTHER ANOMALIES |Among the strangest features found on Venus is a series of |pancake-shaped domes. This surprising discovery was |recounted in the New York Times as follows: |At the news conference yesterday, Dr. R. Stephen Saunders. |the [Magellan] project's chief scientist, showed pictures |of...pancake-shaped domes which he said were "features never |seen before.. on any planet" In one region. seven domes |remarkably similar in size stretch out in a line remarkably |straight for nature...They were presumably formed by extreme |viscous lava pouring out of volcanic vents. The pattrn "is |telling us something about the eruption mechanism. the |viscosity and the eruption rate" But that was as far |as geologists ventured in the interpretation.28 [28 J. Wilford, New York Times (Nov 17, 1990), p. 12.] |The unusual shape of these features should have struck a |chord somewhere among the planetary geologists because |pancake-shaped domes have also been observed on Io. Thus |Carr et al. inform us: |While most calderas [on lo] do not seem to be within shalply |defined edifices a variety of positive relief features are |recognizable. Most are puzzling and difficult to relate to |terrestrial landforms. Among the more comprehensible |because of their resemblance to low volcanic cones, are two |pancake-like constructions...They are nearly circular, and |surrounded by low escarpments. Each has a bright-floored |small crater in the middle. The albedo [reflection |of light by the material of the main edifice is uniform and |close to that of the surroundings. (emphasis added)29 [29 M. H. Carr. H. Masursky, R.S. Strom, R. J. Temle, "Volcanic features of Io," Nature 280 (Aug. 30, 1979), p. 730 p. 730.] |Once again two worlds- Venus and Io share a unique feature |seen nowhere else. ** MACRAE: While unusual in terms of scale (*BIG*) lava domes *are* known on Earth, and are characteristic of silicic lavas. For example, see p.85 and figure 4.26 of: Cas, R.A.F. and Wright, J.V., 1987. Volcanic Successions: Modern and Ancient. Allen and Unwin: London, p.1-528. ISBN 0-04-552022-4. The aerial photograph of an obsidian flow on p.14 bears a lot of resemblance to the "pancake domes" of Venus, including the steep margins. Small satellite vents on the lower left are remarkably similar in appearance and linear trends, again, on a much smaller scale. The features on Venus may be much larger and more round because the lava remains at a higher temperature, so it does not solidify and "dam itself" as often. The "pancake" features on Venus are unusual, but they are not entirely unique. |Of course. normal volcanic domes have also been observed on |Venus. Here Eberhart reported: |Beneath Venus' acid clouds which perpetually shield its |surface from the eyes of Earth-bound obselvers. lie tens of |thousands of low dome-shaped features. For several years |planetary scientists have pondered the origin and |significance of these gentle mounds, which have appeared in |radar images made of the planet since 1983. |Apparently the result of volcanism. the domes constitute |"the most abundant geological feature on the planet" says |Jayne C. Aubele of Brown University: RI. Excited about the |domes and other scientists are beginning to be also..." |Aubele says, "the presence of a volcano on the surface of a |planet always tells us something about the planet. |The presence of tens of thousands of volcanoes overwhelms |me...30 [30 J. Eberhart, "The Diminutive Domes Of Venus," Science News 137, (June 23, 1990), p. 392.] |Although the number of domes on Venus of volcanic origin may |turn out to be smaller in number when Magellan completes its |survey, the great number clearly indicates how abundantly |volcanic Venus must be. ** MACRAE: Or must *have* been. The key test of Ginenthal's model is whether a large amount of volcanism is *currently* occurring. Pointing at volcanic features and saying they are evidence for current activity is misleading. They could be long-dead. |One researcher sums it up this way: |"Magellan's radar survey of Venus found thousands of small |volcanoes dotting the mostly flat landscape, as well as |mountainous volcanic structures several hundred kilometers |in diameter and evidence of massive outpourings of lava."31 |Later we are informed that, "Magellan has found no evidence |of...gradual resurfacing." This suggests that Venus lava |flows were immense in scale, which is what Velikovsky's |concept requires. [31 Science News, Vol. 140, No. 25 & 26 (Dec. 21 & 28, 1991), p. 422.] ** MACRAE: But if there is "no evidence of ... gradual resurfacing", then the observed volcanic features could be preserved at the surface for a *LONG* time. ** ACKER: There is no mention here of the disparate time frames for the resurfacing for Venus (which likely occurred 300-500 million years ago, over a duration of several million years) and the necessary occurrence of _recent_ volcanism required by Velikovsky. Ginenthal makes no case to connect the two. Note also that large outpourings of lava 300-500 mya are consistent with the global resurfacing model. Velikovsky needs this to be recent, which cannot be supported. |HOT SPOTS |For some time now it has been known that certain areas on Io |are far hotter than the surrounding surface terrain. ** MACRAE: Same on Earth. Heat flow is focused in certain regions. E.g., Hawaii and the mid-oceanic ridges versus most of the continental crust.] |Such areas are described as "hot spots." Here Momson tells |us, "In Io's case nature has aided us by channeling much of |the heat flow into a few small areas resulting in hot-spots |with temperatures far higher than the ambient background."32 [32 D. Momson, Ann. Rev. Astron & Astrophy, loc. cit. p. 480.] |Alfred McEwen et al. suggest that' "Observations...show that |most of the hot spots [on Io] have remained relatively |stable in temperature location and total power output at |least since the Voyager encounters and possibly |for the last decade."33 [33 A. McEwen et al., "Volcanic Hot Spots on lo: Correlation with Low Albedo Calderas," Journal of Geophysical Research 90. No. B14, (Dec 10, 1985), pp. 12, 346.] |Hotspots have been associated with surface features on Venus |for a very long time; they were originally found by Earth- |bound radar and confirmed by Venera spacecraft.34 [34 See E. Stofan, R. Saunders, "Geological Evidence of Hotspot Activity on Venus: Predictions For Magellan," Geophysical Research Letters 17:9 (Aug. l990), pp. 1377- 1380.] ** MACRAE: The hot spots were not found directly (i.e. their heat directly measured), evidence for the existence of past or present hot spots was found in the form of high shield volcanoes, which indicates stationary point-sources of magma.] ** ACKER: Why no correlation with Magellan here? |James Head asks: |The question with arguably the broadest implications is |simply how has Venus chosen to get rid of its internal heat |(emphasis in original)...Does Venus cool itself by sending |magma directly from the interior to the surface? Then we |would expect to see widespread volcanic deposits and |numerous "hot spots'.. like those on Jupiter's satellite |Io.35 [35 The New Solar System, loc. cit. p. 85.] ** ACKER: Magellan gravity data does not indicate the presence of hot spot type volcanism in the same manner as Ginenthal cites for Io. The implications drawn below are therefore incorrect. Alpha and Beta Regio may be the surface manifestations of upwelling mantle plumes, but researchers note they cannot determine if they are currently active. Roger Phillips has indicated that the gravity data beneath Atla (not Alpha) Regio indicate a crustal thickness of about 50 km. (Not exactly "molten at shallow depth".) ** MACRAE: Gravitational anomalies are a direct expression of "hot spots" because they heat the crust, and cause it to "float" higher. Two marginal, possible regions of hot-spot activity on Venus (Alpha and Beta Regio) does not even compare to Earth, which has dozens of active hot spots and hundreds of *active* volcanoes (of which 15 or so may be simultaneously erupting at any one time -- Simkin, T., 1993. Terrestrial volcanism in space and time. Annual Review of Earth and Planetary Sciences, v.21, p.427-452).] |Thus the presence of hot-spots suggests that Venus-like Io |is venting its heat via hot-spot volcanism. This, in turn, |suggests that Venus- similar to Io is molten at a shallow |depth. ** MACRAE: Ginenthal may as well say Venus is like Earth because the Earth has hot spots too. Why does Ginenthal insist on drawing an analogy to Io? Hot spot volcanism is thought to have occurred even on Mars. It is not unique to Io, and a thin crust is not a requirement. |One of the great enigmas of the "runaway greenhouse |effect'' is the problem of explaining the source of Venus' |high surface temperature. Based on this analysis it now |seems highly probable that the high surface temperature has |little if anything to do with a greenhouse effect. |Velikovsky's conclusion that Venus' surface heat is derived |from its molten core appears to be correct. ** ACKER: As we can see now, the implications drawn from old data are clearly wrong. The heat source for the surface temperatures (atmospheric) cannot have a volcanic/geophysical origin. ** MACRAE: To produce a significant heat input by geological processes requires an *active* surface like Io's, for which there is no evidence. Yes, the surface of Venus is covered with many volcanoes; yes, there is ample evidence for volcanism, but evidence for *current* activity is obscure at best, and appears to indicate levels of activity even less than Earth, let alone the conditions on Io [Kerr, R.A., 1994 (February 11). A new portrait of Venus: thick- skinned and decrepit. Science, v.263, p.759-760.]. On Earth, geological heat sources contribute about a thousandth of the solar inputs. To be the main source of heat on Venus, geological sources would have to be orders of magnitude more powerful than on Earth, not less. They should be blatantly obvious. Where are they? |THE AGE OF VENUS' SURFACE |In Worlds in Collision Velikovsky suggested that Venus, age |was to be measured in thousands of years rather than |billions. In a recent article in Science a leading |astronomer offered the following observation regarding |the age of Venus' surface: |The planetary geologists who are studying the radar images |streaming back from Magellan find that they have an enigma |on their hands. When they read the geologic clock that |tells them how old the Venusian surface is they find a |planet on the brink of adolescence. ** MACRAE: Of course, they are talking about a completely different time scale from "thousands of years" when they say this, and contrary to Ginenthal's arm-waving about "assumptions" of an age of billions of years, 1) that age is very well established for the Earth and the rest of the Solar System, and 2) even very basic data from Venus indicates its surface is much older than thousands of years, and can not be "fresh" from a molten condition.] ** MACRAE: As noted before, Venus, speaking geophysically, is much less active than Earth. |But when they look at the surface itself, they see a newborn |babe...(emphasis added) Magellan scientists have been struck |by the newly minted appearances of the craters formed...Only |one of the 75 craters identified on the 5% of the planet ** ACKER: This indicates how early in the Magellan mapping mission the article was written. about 900 impact craters (912, according to the _Sky and Telescope_ article) are now identified on the surface of Venus. I am not aware if a comprehensive crater "census" has been compiled yet for Venus based on the Magellan data. |mapped shows any of the typical signs of aging, such as |filling in with lava of volcanic eruptions or being torn by |the faulting of tectonic disruption. ** ACKER: I.e., no tectonics. ** MACRAE: And subsequent to this 1990 assessment, it is now clear that the vast majority of the about 900 known impact craters have little modification by subsequent tectonic activity, including volcanism. There are some, but they are a small fraction. Most have impacted on a hard surface and have no subsequent modification. |But geologists usually measure these fresh-looking craters |had plenty of time to fall prey to the ravages of geologic |change.36 [36 R. A. Kerr, "Venus is looking too Pristine," Science 250 (Nov. 16, 1990), p. 912.] ** MACRAE: So how does Ginenthal explain Kerr's 1994 description of Venus as "thick-skinned and decrepit"? Kerr, R.A., 1994 (February 11). A new portrait of Venus: thick-skinned and decrepit. Science, v.263, p.759-760. I will give G. a hint. It is four years later. G. should look at some of the post-1990 literature more closely? The preliminary gravitational results are in, for example, and a careful inventory of surface features has occurred. |Based on the assumption that Venus is an ancient |body the scientists estimate the surface of Venus to be on |the order of 100 million to 1 billion years old, In short, |even though they are confronted with a surface |that is pristine ** ACKER: Clearly not pristine. The number of craters is consistent with a surface age of 300-500 million years. ** MACRAE: And there is no "assumption" Venus is an ancient body. Its surface is solid and thick. It *is* an old, mostly cooled body. |scientists nevertheless interpret the evidence according |to the theory that Venus is 4.5 billion years old. Thus |Billy Glass tells us that in analyzing Venus' history, |planetary scientists accept "the geologic history of |Venus...based primarily on what we have learned about the |other planets and is necessarily highly speculative. We |assume that Venus was formed 4.5 x 109 y ago." (4.5 billion |years ago)37 [9 B. Glass. Introduction to Planetary Geology (New York, 1982). p. 364.] ** MACRAE: Does the phrase "more than a decade old", or the word, "Magellan" help understand why Glass is making that statement in 1982? It is ridiculous to quote Glass as saying the geologic history of Venus is "necessarily highly speculative" when he is speaking even before Magellan! Immediately before the section Ginenthal quotes, Glass states why the geological history of Venus must be speculative (p.323): "The geological history of the other terrestrial planets is based primarily on studies of their surfaces. Relative ages of surface features are based on superposition, crater counts, and crater morphology. We do not yet know the surface of Venus well enough to work out a relative time scale of events." Glass is doing nothing more than stating the obvious: a high-resolution survey of the entire surface of Venus was not known in 1982. It *is* now. |THE MISSING VENUSIAN REGOLITH |Geophysicists, in order to explain the physical nature of |the Venusian surface, offer the supposition that between 100 |million and a billion years ago the entire planet turned |itself inside out. If one ** ACKER: Not exactly correct. The more apt analogy is a nearly-global event similar to the mid-Cretaceous superplume event which occurred on Earth. Refs: The Mid- Cretaceous Superplume Episode, Scientific American, Feb. 1995, pages 82-87?, by Roger L. Larson. A superplume in the mantle, Nature, 352(6336), 564-565. |were to accept this assumption it would require that over |that period of time between the covering of the surface with |lava flows and the present, erosional forces would break |down the surface rock into detritus to form a regolith. |The problem for the space scientists is that there is no |evidence of a regolith covering the Venusian surface. ** ACKER: Now known to be incorrect. Full analysis of the Magellan data reveals large dune fields. For an example, see NASA publication JPL 400-494 (3/93), page 12, where a dune field (in a deep valley) is shown. The information in the caption allows only a rough estimate of the size of this image, on the order of 20-40 km (12-24 miles) wide. Also, the image may only show a portion of the field. |Moreover, in view of the nature of the highly acidic nature |of the atmosphere it is obvious that there has |been significant erosion of the surface. According to Bruce |Murray et al., "there can be little doubt that chemical |weathering must be very effective |on Venus, surface."38 [38 B. Murray, M. Malin & R. Greely, Earthlike Planets (San Francisco, 1981), p. 70.] ** ACKER: No doubt. To repeat, dune fields are observed. Likely the forces being discussed here are not as effective as water erosion, which cannot occur on Venus. |Venus, atmosphere is known to contain hydrochloric and |hydrofluoric acid, both of which are very corrosive. Paolo |Maffei explains further that, "the atmosphere of Venus also |contains- although in small amounts- hydrogen chloride and |hydrogen fluoride, which reacting with sulfuric acid [known |to exist in Venus' atmosphere could form fluosulfuric acid, |a very strong acid capable of attacking and dissolving |almost all common materials including most rocks."39 [39 P. Maffei, Beyond the Moon (Cambndge, 1978), p. 44.] |According to the scientists, Venus has been subjected to |this intense weathering of its surface for at least 100 ** ACKER: Chemical weathering is not anywhere as close as to the power of physical weathering (example: freeze-thaw fracturing) which can occur on Earth. To characterize chemical weathering as "intense" is incorrect. ** MACRAE: If there is nothing to remove the altered minerals on the surface of the rock, the chemical products build up and protect the surface from further alteration. On a planet without running water, erosion will not be effective. ** ACKER: Furthermore, acids work best in the presence of water, which yields dissolved hydrogen ions. The lack of water in the Venusian atmosphere renders the effect of HF, HCL, etc. molecules practically nil. (See references on acid rain and dry deposition for further information.) ** MACRAE: Without water, chemical weathering is also very ineffective. This can be observed in desert areas, where bedrock surfaces chemically alter very slowly. And a typical Earth desert is many, many times wetter than the conditions on Venus. In short, the lack of water on Venus means erosion processes are slow -- much slower than Earth. (It is *extremely* dry at the surface -- the atmosphere contains a "hundred thousandth as much water as the Earth has in its oceans. If all of Venus's water could somehow be condensed onto the surface, it would make a global puddle only a couple of centimetres deep". p.93, Luhmann, J.G.; Pollack, J.B.; and Colin, L., 1994 (April). The Pioneer Mission to Venus. Scientific American, v.270, no.4, p.90- 97.)] |million years. Over this period of time the planet should |have developed a covering of weathered material. ** ACKER: See references to dune fields. |Nevertheless, George McGill et al., inform us |that: Radar and Venera lander observations imply that most |of the surface of Venus cannot be covered by unconsolidated |wind blown deposits; bulk densities on near surface |materials are not consistent with aeolian sediments...Thus |present-day wind-blown sediments cannot form a continuous |layer over the entire planet.40 [24 G. McGill et al., Venus (Tempe, 1983), pp. 95-96.] ** MACRAE: 1983. Pre-Magellan. ** ACKER: Note the situation of the Great Sand Dunes in Great Sand Dunes National Monument, Colorado. The valley floor is essentially clean -- the dunes are found below a gap in the Sangre de Cristo mountains where the prevailing winds are funneled. On the rock surface of Venus, it would be expected that a similar process would occur -- and (as stated before) dune fields are found, and in the case of the cited Magellan image, in a valley. |Thus, despite the fact that erosional processes are clearly |at work on Venus, surface, there is no evidence of a |regolith. ** ACKER: Shown to be wrong. [** MACRAE: And not much is expected anyway.] Much of the regolith might be impact- generated dust and volcanic ash, and not eroded material at all. |Bruce Murray, in dealing with this enigma wonders: |Russian cIose-ups of Venus were surpnsing. I had presumed |that its surface was burried under a uniform blanket of soil |and dust. ** ACKER: Shown to be an incorrect assumption. ** MACRAE: And some sediment is visible in the Venera images. |Chemical weathering should be intense in such a hot and acid |environment. Unknown processes of topographic renewal |evidently manage to outstrip degradation and burial 4 |[emphasis added]. [4 N. Chan. L. Esposito, T. Skinner. "International Ultraviolet Explorer Observations of Venus SO2 and SO", Journal of Geophy. Res. 95 (May 20,1990). p. 7485.] |In order to explain the lack of a Venusian regolith the |scientists imagine a process that has no scientific basis |for its action to reconsolidate the detritus on Venus. ** MACRAE: Who says/said this? Where is the citation? |Nevertheless, let us assume that Venus' erosion rate is |extremely weak ** MACRAE: Yes. |and that it is not turned back into rock at the surface by |unknown processes. ** MACRAE: No. Not necessary. See above. |What do we find? If we allow a tiny erosion rate of one |millimeter per hundred years, then in 100 thousand years we |produce one meter of loose material on the surface of Venus, |which is equal to about 40 inches. ** MACRAE: This is not a tiny erosion rate as an *average* rate on the entire surface. It is actually quite large. |However. in 100 million years we generate a kilometer of |detritus. which is over 3000 feet of this |loose material. Under no known condition can this much |matter at the surface be turned to solid rock, and this is |admitted by the scientists. ** MACRAE: One of the major fallacies with this analysis is that a 1-mm per 100 years rate of erosion would tend to cover the bedrock, and prevent further erosion. Erosion is ineffective unless altered material is removed and fresh material is exposed to reaction with the atmosphere. Venus has no rivers or rain. It is quite possible a rind of chemically altered rock develops on the surface of the bedrock and then it ceases to alter further. With no water to enhance chemical weathering and remove altered material, the rocks may briefly erode at a rate of "1 mm per 100 years" and then virtually stop. |What we find at the surface |of Venus is the detritus of an erosion rate that is only a |few thousand years oId. Only by ignoring this clear |evidence can the astronomers support the view that Venus' |surface reflects events tracing to processes |occurring between 100 million and one billion years ago. ** ACKER: The presence of dune fields strongly weighs against this argument. |Although Magellan has cast doubt upon most of the scientific |establishment's predictions regarding the nature of Venus' |surface, a belief in a 4.5 billion year old age of the |planet Venus is sti11 enshrined as dogma. In accordance |with this theory, it is believed by the space scientists |that the degradation of craters on Venus' surface must have |occurred over hundreds of millions of years. As the ** ACKER: Very few of the craters on Venus are degraded, consistent with the estimated surface age and estimated level of volcanic activity. ** MACRAE: The surface is solid and thick, also consistent with a planet that cooled long ago. |situation on Io proves, however, degradation does not |require long time periods. Io's craters decay over |extraordinarily short time periods measured in |weeks or months. ** MACRAE: Because they are buried in the products of volcanic eruptions, not because they are eroded. |On Venus this period might take years. |Based on the indications (cited above) that both Venus and |Io are molten at shallow depth and are highly volcanic, |Venus' craters would by no stretch of the imagination |require millions of years to degrade. ** MACRAE: Then why are more of the craters, or even most or all of them, not covered with volcanic deposits? Why didn't Magellan observe obvious changes in volcanic features during its multiple passes? Voyagers 1 and 2 had no problem detecting change on Io in only 4 months. ** ACKER: Venus has not been shown to be highly volcanic; therefore, the vast majority of the craters are pristine. |How then do scientists explain the fact that Venus' craters |look so pristine? Here Kerr observes: |Magellan scientists strove to explain the paradox of young |looking craters on a relatively old surface. They raised |the possibility that several hundred million years ago. a |planet-wide outpouring wiped the slate clean, drowning any |existing craters in a flood of lava. Then the flood would |have had to tum off fairly abruptly so the craters formed by |subsequent impacts would remain pristine. But such a global |episode of volcanism generates another mystery. |How could Venusian volcanic activity ebb so abluptly?42 [36 R. A. Kerr, "Venus is looking too Pristine," Science 250 (Nov. 16, 1990), p. 912.] ** ACKER: See discussions of the Earth's mid- Cretaceous superplume episode, notably in the recent article (cited above) in _Scientific American_. |No doubt there will be other, equally imaginative, scenarios |advanced in order to explain away this dilemma of so few |craters showing signs of decay. To return to Kerr: ** ACKER: Not a dilemma based on current knowledge. |But surface remodeling is going on after all. Magellan |scientists told a large crowd at the AGU [American |Geological Union] meeting. More recent images show the |ravages of time, but in a fashion that leaves few aged |craters."(emphasis added) ** ACKER: An unsupportable assertion is made below. The refutation notes above illustrate why the AGU statements above are now the prevailing, supported scientific view of the surface of Venus. |This is not so much an explanation of the findings as a |directive that the evidence is to be interpreted as such. |This is not the only problem, however. Again we cite Kerr: |The expanded view reveals four nearly continent-sized areas, |ranging from a few million to 5 million square kilometers, |that have no impact craters at all. According to Magellan |team member Roger Phillips of Southern Methodist University |in Dallas, the absence of impact craters- despite a steady |rain of asteroids and comets onto the Venusian surface- ** ACKER: Note the term "steady rain". Here Ginenthal argues AGAINST the likelihood of Venus having been subjected to a flux of impactors different than elsewhere in the Solar System! I.e., by quoting Phillips, he is agreeing with the assumptions Phillips uses to construct his model of the surface of Venus. |means that in the recent geologic past the craters were |wiped out either by lava flooding across these areas or |by tectonic faulting, stretching and compression. ** ACKER: Consistent with the prevailing view. Crater distribution is not entirely random. Phillips is a proponent of a more gradual resurfacing process than the global resurfacing episode preferred by Schaber, which is (at the present time) the predominant view. |The volcanic activity required to resurface the crater-free |regions would be impressive by any standards, Phillips says. |For example, it took at least a million cubic kilometers of |lava over a few million years to produce the 66-million- |year-old Deccan Traps of India...But the lava-covered areas |already uncovered on a small part of Venus by Magellan must |have all formed within the past few tens of millions of |years to have escaped being marked by impact craters.43 [43 R. Kerr, Volcanoes: Old, New, and-Perhaps-Yet to se," Science 250 (Dec. 24, 1990), p. 1660.] ** ACKER: About 900 impact craters are now identified on Venus -- far more than on Earth. Also note the time- scale here - "tens of millions of years". |So Magellan scientists are still left with an enigma. What |is clearly implied by the radar and photographic evidence is |that immense outpourings of lava have occurred over huge |areas of Venus' surface, covering over everything including |craters. The scientists still cannot explain why there are |so few craters that are degraded or flooded or why Venus ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |suddenly poured out its lava in oceanic amounts. But ** ACKER: Yes, they can. The global resurfacing scenario is consistent with the Magellan data. Note also that the lava has not covered the 900+ observed craters. ** MACRAE: More importantly, how does *Ginenthal* explain why there are "so few craters that are degraded or flooded"? They should be if Venus is currently as active as claimed. |all of this is clearly what one would expect to find from |the theory that Velikovsky advanced in "Worlds in |Collision", whereby Venus was only recently subjected to |tremendous stresses and participated in numerous clashes |with other planets. ** MACRAE: I disagree completely. How does Ginenthal explain the gravity data, the high topography, or the relative freshness of craters with a Velikovskian model? These are completely inconsistent with a crust that is thin and hot. ** ACKER: Based on a consideration of all the data, this cannot be supported. |IRON |As a newborn planet, Venus would not have fully |differentiated so it remains possible that all its iron has |yet to sink to its core. ** MACRAE: Without plate tectonics, Venus also would be less chemically differentiated than the Earth, although the iron core would still be present. |Accordingly, it was reported in Astronomy that: |Maxwell Montes...poses a big problem in interpretation. |Parts have electrical properties that indicate the surface |contains "flakes.. of some unknown mineral. most likely iron |sulfides. iron oxides. or magnetite. Iron sulfides ("fool's |gold..) fit the observations best. but studies have shown |that they would be quickly destroyed by the corrosive |Venusian atmosphere. Iron oxides (such as hematite) and |magnetite are also possible. but the presence of either is |not easy to account for.44 [44R. Burnham, "Update on Magellan," Astronomy (Feb. 1991), p. 46.] ** ACKER: Because Magellan's information is only the reflections of radar, very little chemical information on the surface can be deduced. The high-reflective regions still pose a problem of interpretation. One author has suggested pyrrhotite (not pyrite, or "fool's gold", as mentioned above.) It is noted that the thick atmosphere and high temperature and pressure induce conditions that are quite unusual, which could lead to unusual chemical phases that are not stable on Earth but are stable on Venus. ** MACRAE: And, interestingly enough, phases that are stable in the absence of water, as is the case of many metallic minerals, including the sulphides being discussed. ** ACKER: Furthermore, it is not even definite that the reflective substances are iron-based, only that their dielectric constant is similar to substances that are iron based, such as iron sulphides. To attach a great deal of importance to hypotheses about these substances and suggested weathering rates is to attach too much reality to informed speculation. Note added in proof: ====== _New Scientist_, 4 March 1995, pg. 20: "The metal-plated mountains of Venus". Describes paper by Brackett, Fegley, and Arvidson (Washington U., St. Louis) -- J. Geophys. Res., vol. 100, p. 1553- ) in which the depositional process for compounds such as lead sulphide, copper chloride, and Zn, Sn, As, Bi, and Sb compounds on the higher elevations of Venus is described, compounds which could coat the rocks with a layer mm in thickness possessing the proper radar reflective properties. Get this: they come from volcanic deposits, which evaporate slowly at 740 K (low elevations) but would recondense at 660 K (high elevations)! It's a UNIFORMITARIAN process! (Estimate of mm-thick for a 10-million year period). ====== |If indeed iron is to be found upon the surface of Venus it |would support the claim that it is a youthful planet in the |early stages of cooling.45 A ** ACKER: Basically, no inferences are useful at this time. Ginenthal is speculating uselessly here. ** MACRAE: Well, there is something with interesting electrical properties, but that is all that can be said [although see above for recent developments] |planet that had differentiated its iron into its central |core would not be expected to pour iron onto the surface |with volcanic materials. The reason that the iron compounds ** ACKER: The above, however, is ridiculous in the extreme. Earth has a "differentiated" layered structure, with a great deal of iron in the core; that does not prevent volcanoes from erupting basalt, which is composed primarily of iron-rich minerals. [MACRAE: Some are even erupted with iron sulphides in them.] |have not completely corroded in Venus' corrosive atmosphere, |most probably, is that these outpourings of iron are |extremely recent surface coverings measured in perhaps a few |years. Iron on Venus' surface is clear evidence that |supports Velikovsky. ** ACKER: Since this point is so clearly founded on very little real data, it is only speculation. ** MACRAE: I would say it is just wrong. Finding iron sulphides or other iron minerals in significant concentrations on the surface of the Earth is not that unusual. |ARGON |The superabundance of 36Argon, and the tiny amount of 40Ar, |are glaring puzzles for the conventional view of Venus' |history but perfectly consistent with Velikovsky's view that |Venus is a youthful planet. As Glass explains, the 40Argon |builds up over time by the breakdown of 40Potassium: ** MACRAE: Actually, it is an oversimplification to say "40Ar builds up over time". Ar (all isotopes) is constantly lost from the atmosphere. 40Ar is produced by radioactive decay, and gets released from the interior of the planet along with other stable isotopes. Over time, the *ratio* of 40Ar to other isotopes increases, but Ar is continually lost. |The ratio of the mass of radiogenic 40Ar to the mass of |Venus is smaller by amount of a factor of 15 than the value |for the Earth...Since 40Ar within a planet increases with |time due to radioactive decay of 40K, the amount Of 40Ar |should be higher if the primary outgassing took place late ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |in the planet's history.46 ^^^^^^^^^^^^^^^^^^^^^^^^ [46 B. Glass. Introduction to Planetary Geology (New York, 1982). p. 314.] |If Venus did not outgas much 40Ar over time why did it |outgas so much 36Argon? ** MACRAE: Non sequitur. Only Ar is outgassed -- all isotopes. You can not differentially outgas 36Ar or 40Ar. If there is "so much 36Ar" it is because a smaller amount of 40Ar has been produced by radioactive decay, mixed with the other isotopes, and outgassed from the crust. ** ACKER: This would seem to indicate a cap on the release mechanisms of 40Ar. If the release mechanism is primarily volcanic, then Venus has a low level of volcanism! Does the expression "shooting oneself in the foot" come to mind? ** MACRAE: Exactly. In fact, you do not have to take my word for it. Ginenthal quotes Glass as an authority for the 40Ar data. Glass says effectively the same thing as you just interpreted, in the next *sentence* after the part he quoted. |If Venus lost |nearly all its 40Ar why did it retain 36Argon? ** MACRAE: Again, non sequitur. Venus can not lose "nearly all its 40Ar" without losing 36Ar too. Venus can only lose Ar of all isotopes (there are some tiny effects due to slightly different mass and therefore escape velocities, but they are not significant).] |If, on the other hand, the great outflowings of lava |released great amounts of 36Argon why didn't these |outpourings also release large amounts of 40Ar? ** MACRAE: Again, differentially releasing one or the other isotope is not possible. The only explanation possible is one that produces low amounts of 40Ar in the crust, or an explanation that releases low amounts of Ar (of any kind) during the recent history of Venus (because these "younger" Ar releases will have higher 40Ar concentrations than later ones). There are several possible explanations for this. The most obvious one is to suggest Venus has less K in its bulk composition, and always has, so it always produces less 40Ar than Earth. This is not likely given the density similarities between the two planets, but is possible, and would even explain why Venus appears (currently) to be less tectonically active than the Earth (because decay of 40K is one of the major sources of radiogenic heat in the Earth, and heat is what drives plate tectonics. [ACKER: Negative feedback loop. Less 40K, less heat. Less heat, less volcanism. Less volcanism, less Ar degassing.] Another explanation is the greater chemical differentiation which has occurred on Earth due to plate tectonics, which tends to concentrate K in the continental crust. This puts the source of 40Ar closer to the surface, and makes the release of 40Ar-rich Ar more efficient. This explanation is reasonable one for Venus, because it does not appear to have active plate tectonics. A less differentiated Venus would tend to trap more 40Ar deep in its interior than the Earth does. A final, and probably most obvious explanation is that release of Ar (of any kind) from the crust of Venus is not currently, or recently, extensive. This fits the indications of minimal *current* tectonic activity on Venus, and its thick crust. If Ar is not being efficiently released from the crust, then the "young" 40Ar-rich inputs are minimal, and the "old" atmospheric Ar (which is relatively depleted in 40Ar by comparison) is dominant. Most importantly, if Venus was as active as claimed by Ginenthal, the amount of 40Ar should be high, because the outgassing of crustal Ar would be very efficient. In fact, finding a low 40Ar concentration is completely consistent with what is known of tectonic/volcanic activity on Venus (little current activity, or much in the last few hundred million years), and completely contrary to the expectation if Ginenthal's model were correct. I did not check Glass until after I had written the above sections (based on general knowledge about K and 40Ar on Earth), and the following quote is a bit repetitious, but the explanation I provided is effectively what Glass says a few sentences beyond the part that Ginenthal quotes (also p.314): [Ginenthal effectively quotes this part] "Since 40Ar within a planet increases with time due to radioactive decay of 40K, the amount of 40Ar should be higher if the primary degassing took place late in the planet's history." [He does not quote this part] "Thus, the comparable amounts of outgassed N2 and CO2 for Venus and the Earth imply comparable degrees of outgassing during the early epoch; whereas the smaller amount of 40Ar for Venus [versus the Earth] suggests that outgassing during later epochs has been less efficient (Oyama et al., 1979b)" [Oyama, V.I.; Carle, G.C.; Woeller, F. and Pollack, J.B., 1979b. Laboratory corroboration of the Pioneer Venus gas chromatograph analyses. Science, v.205, p.52-54] I.e., the low amount of 40Ar relative to N2 and CO2 on Venus and relative to the Earth indicates Venus has been *LESS* geologically active in recent history than the Earth and therefore releasing *LESS* (40Ar-enriched-with-time) Ar -- the exact opposite of what is expected if Ginenthal's explanation were correct. Rather than an anomaly for the conventional explanation, this interpretation is confirmed by all the other available data (e.g., from Magellan, see above), and *directly* contradicts Ginenthal's presentation. Why he even included it, I do not know. |OXYGEN |Ultraviolet radiation photodissociates CO2, SO2 and H2O; |over millions of years oxygen should have become plentiful |in Venus, atmosphere, but it remains a minute constituent. |Venus, water vapor cannot have escaped in less than 20 |billion years. Where then is Venus, water? To argue Venus |had no water but retains other volatiles is a basic |contradiction. ** ACKER: Venus has now been shown to have more atmospheric water vapor than previously thought, an observation which constrains models of the atmosphere. ** MACRAE: Note that the amount of water is still minute compared to Earth.) Furthermore, a reactive surface mineralogy could consume free oxygen via oxidation. See below. |Moreover, Venus' middle atmosphere should have been |converted to CO2 and O2 over a few thousand years, yet this |is not the case. To argue that the Sun's magnetic flow |implants and removes gases is based on assumptions that have |never been proven and does not address all the problems of |the other gases which exist and are unrelated to the solar |wind. ** ACKER: One wonders where Ginenthal comes up with this idea. It is not found in any literature discussions. ** MACRAE: It does not even make basic chemical sense. Where does the C go? What happens if oxygen is present when the C occurs in 450 Celsius near-surface temperatures? It oxidizes. Ginenthal's explanation makes no sense at all. And how the "Sun's magnetic flow" (?? the solar wind) is supposed to be involved, I have no idea. |A similar problem surrounds the prevalence of hydrofluoric |and hydrochloric acids. Both of these acids are neutralized |by new surface rock; oxygen, on the other hand, will unite |with new surface rock. If nearly all of Venus, oxygen was |removed by uniting with new outflows of molten rock why |didn't these great outflowings neutralize all the |hydrochloric and hydrofluoric acid? ** MACRAE: Maybe because most volcanic eruptions on Earth release large quantities of HF and HCl? There is absolutely no reason to suggest volcanic activity consumes more HF and HCl than it erupts. In fact, I would expect the opposite. ** ACKER: This is simply answered by the lack of much liquid water on the surface of Venus. Acids are made powerful in solution by the donation of hydrogen ions -- without water, they are gases. Oxygen, and especially oxygen radicals and ozone, are highly reactive gases, an action different than acid interactions. Ginenthal shows a lack of basic chemical knowledge here. |The lack of abundant oxygen on Venus and the existence of |hydrochloric and hydrofluoric acid are only congruent with |one theory-that of Immanuel Velikovsky. ** ACKER: Since Ginenthal shows such a lack of basic chemistry knowledge, his argument here hardly shows support for anything or anybody. [MACRAE: Agreed. And a basic misunderstanding of what volcanoes produce.] |THE GREENHOUSE EFFECT |For years the scientific community has maintained that the |great heat of Venus is derived from an atmospheric |greenhouse effect. Gary Hunt and Patrick Moore outline the |ingredients necessary to generate a large and |powerful greenhouse on Venus: |CO2 is responsible for about 55% of the trapped heat. A |further 25% is due to the presence of water vapor, while SO2 |which constitutes only 0.02% [2/100 of a per cent] of the |atmosphere, traps 5% of remaining infrared radiation. The |remaining 15% of the greenhouse is due to the clouds and |hazes which surround the planet.47 |While carbon dioxide is certainly present on Venus. it can |account for only 55% of the greenhouse effect. As Barrie |Jones explains, other factors are also necessary to make the |greenhouse work: |"Efficient trapping [of heat] cannot be produced by CO2 |alone, in spite of the enormous mass of CO2 in the |atmosphere. This is because CO2 is fairly transparent over |certain wavelength ranges to planetary wavelengths. |Radiation could escape through these "windows" in sufficient |quantities to greatly reduce the greenhouse effect below |that which exists. It is by blocking of these windows by |SO2, by H2O, and by the clouds that greatly increases the |greenhouse effect.48 |In short, it is crucial to the runaway greenhouse effect |that there be sufficient water, sulfur dioxide, and haze to |maintain the heat holding capacity of the planet. Respecting |water. especially in the lower atmosphere, the scientists |have been looking for this vapor for a very long |time. As late as September 1991, water vapor has not been |found in anything like that amount needed to support the |contention that the greenhouse is a foregone conclusion. |According to R. Cowan: ** ACKER: This argument is flawed in light of the new information on the water vapor content of the atmosphere (information based on oxygen isotope information, primarily). |A research team has focused on the greenhouse puzzle...The |absence of water vapor above Venus' cloud banks mystifies |scientists because models of the planet's strong greenhouse |effect suggest that [water] vapor plays a key role in |maintaining the warming. Researchers have now looked for |water below the cloud bank and down to the surface-and their |search has come up dry. |Evidence of a dry Venus may force researchers to consider |whether other chemicals could create and sustain the |planet's greenhouse effect. says David Crisp of the Jet |Propulsion Laboratory...who coauthored the new report.49 ** MACRAE: So Ginenthal is aware of the extremely dry conditions on Venus, yet is unaware of the implications for chemical weathering. |Now when a vapor responsible for 25% of the efficiency of |the greenhouse-effect has been sought in vain for some 20 |years it implies that a major problem exists with the model |in question. Furthermore, in our earlier discussion of the |SO2 and haze in the Venusian atmosphere we have shown that |measurements indicate that these materials are transient |products and do not sustain themselves for long periods of |time. With this additional undermining of the greenhouse |effect the process becomes more and more difficult to |imagine. |One of the major theoretical supports of the greenhouse |model is the belief that Venus is in thermal balance. Over |and over we are told that measurements of the cloud tops for |infrared emissions show conclusively that the amount of |sunlight incident on the planet is equal to the infrared |radiation emitted by Venus. However. this must also be |supported by in situ measurements throughout the atmosphere: |Radiative balance occurs [on a planet] at every level when |the amount of downward-directed solar radiation that is |absorbed is equal to the amount of infrared radiation that |is emitted upward. When local temperatures satisfy this |balance the atmospheric temperature is maintained. (emphasis |added)50 |Not only must there be thermal balance at one level of the |atmosphere. this themal balance must exist at all levels |throughout the atmosphere to confirm thermal balance. ** MACRAE: The feature being ignored here is the *transport* of warm atmosphere to different altitudes. While "thermal balance" may not be maintained throughout the atmosphere by *radiative* processes, it can by transport processes. Therefore, there is no reason to expect that measurements of *radiative* processes are always going to yield "thermal balance", particularly if the atmosphere is not very transparent. |That this is not the case upon Venus has been known for some |time. As Iong ago as 1980 Richard Kerr reported in Science |that: |When [4] Pioneer Venus probes looked at the temperature. |each one found more energy being radiated up from the lower |atmosphere than enters it as sunlight...To further |complicate the situation. the size of the apparent upward |flow of energy vanes from place to place by a factor of 2 |which was a disturbing discovery.5 |Kerr adds a telling and fundamental observation in this |regard: "The much ballyhooed greenhouse effect of Venus can |account for only part of the heating."52 [emphasis added] |This simply means that the measured evidence from in situ |probes precludes the possibility that Venus is in thermal |balance. |Since this evidence was confirmed by four probes it is |highly unlikely that each probe could have been in error. |What is most significant is the variation from place to |place. the amount of heat rising varying at some places by a |factor of 2. Thus, if in one region of Venus' atmosphere |the temperature was x degrees, in another area it was 2x |degrees. This means that there was at least twice the |amount of heat coming up at 2x than could have been supplied |by the greenhouse effect. It is most unlikely that in one |region of Venus' atmosphere the greenhouse effect is twice |as strong as in the other regions. |CONCLUSION |A fair reading of history will show that conventional |astronomers have a very poor record when it comes to |predicting the surface conditions of Venus. Such is not the |case with regards to the thesis outlined by Immanuel |Velikovsky in 1950. ** MACRAE: Where are the petroleum fires? |As this essay has sought to show, the evidence from Venus is |fully consistent with the thesis of its anomalous origin and |tumultuous recent history as set forth in Worlds in |Collision. ** MACRAE & ACKER: This could not be further from the truth. The crust of Venus is thick and solid, there is little evidence of current volcanic activity, there are topographic features that are impossible for a planet with a thick, hot crust, the low ratio of 40Ar actually argues *against* the model Ginenthal describes, and there is nothing remotely approaching the conditions predicted by Velikovsky's model (Ginenthal draws an analogy to Io, which I think is reasonable, but Venus is not like Io!). Venus-Io similarities are superficial at best. Venus does not even appear to be as geologically active as Earth. |Indeed, it is this author's sincere hope that the day will |come when members of the scientific community will find the |courage and integrity to call for a full and proper |investigation of Velikovsky's hypothesis. ** MACRAE: I sincerely hope that Ginenthal will read some of the literature on Venus in the last 3 years, and reconsider the claims he has made about the early results from the Magellan probe. The results are not as rosy for a Velikovskian scenario as he claims. Venus is a fascinating planet with unusual geology, and I am certain interpretations of it will change. It would not surprise me if some degree of activity is eventually found. But the results Ginenthal uses are from 1990 or so, as the Magellan results were just coming in, and much of what he presents here is already outdated and clearly wrong, if not wrong from the start (e.g., confusing impact craters with volcanic calderas). It is time for an update. ========= Ginenthal References: I L. Coli, "Venus: The Veiled Planet", The Planets, B. Preiss ed.. (New York, 1985), p. 277. 2 E. Opik. The Oscillating Universe (New York, 1960), p. 63. 3 I. Asimov, "The Unknown Solar System", Discover (Oct. 1989). p. 40. 4 N. Chan. L. Esposito, T. Skinner. "International Ultraviolet Explorer Observations of Venus SO2 and SO", Journal of Geophy. Res. 95 (May 20, 1990). p. 7485. 5 L. Esposito, "Does Venus Have Active Volcanos?" Astronomy (July 1990). p. 45. 6 J. Pollock. "Atmospheres of the Terrestrial Planets" The New Solar System, ed. J. Beatty & A. Chaikin. (New York. 1990). p. 93. 7 D. Morrison. T. Owen, The Planetary System (New York, 1988), p. 235. 8 D. Momson, "The Satellites of Jupiter and Saturn," Ann. Rev. of Astron & Astrophysics 20 (1984), p. 480. 9 B. Glass. Introduction to Planetary Geology (New York, 1982). p. 364. 10 M. H. Carr. H. Masursky, R.S. Strom, R. J. Temle, "Volcanic features of Io," Nature 280 (Aug. 30, 1979), p. 730. II D.Momson. "The Enigma Called Io" Sky & Telescope (March 1985), p. 201. 12 New Scientist (Nov 4, 1989), p. 34. 13 carr. op. cit., p. 730. 14 R Saunders, "Surface of venus,,, Scientific American (Dec. 1990), p~ 15 Discover, (Jan. 1991), p. 38. 16 According to J.E. Guest and R. Greeley, RGeology of the Moon" (New York) 1977), p. 99. 17 New York Times (Sept. 27, 1990), p. B4. 18 The New Solar System, J.K. Beatty & A. Chaikin eds., (New York, 1990), p. 181. l9 1bid.. p. 181. 20 R. Saunders, "The Surface of Venus," Scientific American (Dec. 1990), p. 63. 21 1bid. 22 A. Chaikin, "Magellan Pierces the Venusian Veil," Discover (Jan. 1992), p. 22. 23 B Glass. loc cit., p. 364. 24 G. McGill et al., Venus (Tempe, 1983), pp. 95-96. 25 R. Cowan, "Magellan finds wind sculpture on Venus," Science News (March 28, 1992), p. 198. 26 Robert Burnham, Astronomy (Sept. 1991) p. 37. 27 1bid., pp. 37-38. 28 J. Wilford, New York Times (Nov 17, 1990), p. 12. 29 Carr et al., Nature, loc cit., p. 730. 30 J. Eberhart, "The Diminutive Domes Of Venus," Science News 137 (June 23, 1990), p. 392. 31 Science News, Vol. 140, No. 25 & 26 (Dec. 21 & 28, 1991), p. 422. 32 D. Momson, Ann. Rev. Astron & Astrophy, loc. cit. p. 480. 33 A. McEwen et al., "Volcanic Hot Spots on lo: Correlation with Low Albedo Calderas," Journal of Geophysical Research 90. No. B14, (Dec 10, 1985), pp. 12, 346. 34 See E. Stofan, R. Saunders, "Geological Evidence of Hotspot Activity on Venus: Predictions For Magellan," Geophysical Research Letters 17:9 (Aug. l990), pp. 1377- 1380. 35 The New Solar System, loc. cit. p. 85. 36 R. A. Kerr, "Venus is looking too Pristine," Science 250 (Nov. 16, 1990), p. 912. 37 B. Glass, op. cit., p. 324. 38 B. Murray, M. Malin & R. Greely, Earthlike Planets (San Francisco, 1981), p. 70. 39 P. Maffei, Beyond the Moon (Cambndge, 1978), p. 44. 40 G. McGill, op. cit., p. 94. 41 B. MulTay, Journey into Space (New York, 1989), p. 126. 42 Kerr., loc. cit. 43 R. Kerr, "Volcanoes: Old, New, and-Perhaps-Yet to see," Science 250 (Dec. 24, 1990), p. 1660. 44R. Burnham, "Update on Magellan," Astronomy (Feb. 1991), p. 46. 45 In his analysis of the conditions of the early Earth. Carl Woese maintains as do most geologists and geophysicists that in that early period there was iron at the Earth's surface. See C. Woese, "An Alternative to the Oparin View of the Primeval Sequence," The Origin of Life and Evolution, H. O. Halvorson and K.E. van Holde. eds., (New York, 1980), pp. 65-76 46 B. Glass, loc cit., p. 314. 47 G. Hunt & P. Moore, The Planet Venus (London, 1982), p. 132. 48 B. Jones, The Solar System (New York, 1984), pp. 138- 139. 49 R. Cowan, Science News (Sept. 14, 1991), p. 167. 50 Encyclopedia Britannica Macropedia, Vol. 2, (London, 1990), p. 523. 51 R. Kerr, Science 207, (1980), p. 289. -- -Andrew macrae@geo.ucalgary.ca home page: "http://geo.ucalgary.ca/~macrae/current_projects.html"