... Science Frontiers ONLINE No. 134: MAR-APR 2001 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Missing Martian Meteorites Scientists scouring the Antarctic snowy wastes have collected 13 so-called SNC meteorites, which by virtue of their compositions are likely from Mars. These tiny chunks are believed to have been blasted off the Martian surface by five or six impacts of much larger meteorites. All save one of these Martian meteorites have formation ages of about 1.3 billion years. The only part of the Martian surface believed to be 1.3 billion years old is the TMOM (Tharsis Montes and Olympus Mons) region. The rest of Mars -- about 90% of it is much older. To have 12/13ths. of the Martian meteorites originate from 1/10th. of the planet's surface is highly unlikely. Something is wrong somewhere; probably a bad assumption. And what about that 13th. meteorite that did not get ejected from the TMOM region? This is ALH 84001, the controversial meteorite that contains strange worm-like structures resembling terrestrial bacteria. (See SF#130, #116, #110, #108, and #101.) (Taylor, Richard L.S ., and Mittlefehldt, David W.; "Missing Martian Meteorites," Science, 290:273, 2000.) From Science Frontiers #134, MAR-APR 2001 . 2001 William R. Corliss Other Sites of Interest SIS . Catastrophism, archaeoastronomy, ancient history, mythology and astronomy. Lobster . ...

... Science Frontiers ONLINE No. 130: JUL-AUG 2000 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Anomalous High Altitude Luminosity (AHAL)When meteors plunge into the earth's upper atmosphere, friction with the air causes them to incandesce and burn up. The smaller ones are completely consumed. A few bigger ones reach earth and are renamed "meteorites." So far, all of this is well-understood. But when meteors begin to burn up much above 100 kilometers, a problem arises. The air there is normally much too thin to cause incandescence and burn-up. Observational anomalies are abundant. Two Leonid fireballs were seen glowing at 160 kilometers by Japanese scientists. In 1998, a Dutch team in China detected bright Leonids at 200 kilometers! In addition, some Russian reentering space-craft began glowing well above 100 kilometers. ANAL is a solid phenomenon. Of course, the density of the upper atmosphere does increase somewhat when solar activity is high. Atmospheric gravity waves can also cause the atmosphere to bulge out. But these effects are inadequate to explain all observations. R. Spalding, at Sandia National Laboratories, ventures that ions in the upper atmosphere are electrostatically attracted to meteors and create light when they collide with them. A. Ol'khovatov suggests that "plasma instabilities" may be involved. To learn more about these, go to the latter's web site at: www.geocities.com/CapeCanaveral/Cockpit/3240/ (Ol'khovatov, Andrei; "Anomalous High ...

... . (SF#115) So, we have abundant evidence of a terrestrial event encompassing much of the planet but no "smoking crater"! The mystery deepens when one realizes that whatever cataclysm sent the Australian tektites aloft may have been comparable in magnitude to the impact that extinguished the dinosaurs (and other fauna) some 65 million years ago. This much older event has its craterburied below the Yucatan and is further marked by widespread biological extinctions. In contrast, the Australasian-tektite event is not only minus an obvious crater but seems to have had scant effect on the earth's cargo of sensitive life forms. It was a strangely "gentle" event despite the rocky deluge of tektites. What really happened? (Paine, Michael; "Source of the Australasian Tektites," Meteorite, p. 24, February 2001. Varricchio, Louis; "Tektite Origins," Meteorite, p. 4, May 2001.) Comment. Was the Australasian-tektite event an encounter with mirror matter, perhaps like Tunguska might have been? We would be derelict not to mention here the claim by J.A . O'Keefe and others that the rain of Australasian tektites originated in an impact event that occurred not on the earth but rather on the moon. A lunar impact would obviously not require a terrestrial crater, and earthly biota would be spared. The debate over the possible lunar origin of this tektite fall has been particularly bitter. Those interested should refer to: O'Keefe, John A.; "The Coming Revolution in Planetology," Eos, ...

... were employed as well as an all-sky TV camera equipped with an image intensifier. All photographed meteors began to visibly burn up below 130 kilometers, but the TV camera consistently picked up the same meteors at higher altitudes. Both sets of cameras recorded the same final burn-up heights. The most startling observation was a meteor that the TV camera detected at roughly 200 kilometers altitude. The highest observed Leonid meteor with initial mass of about 1 kg started radiating at an altitude of almost 200 km. The origin of meteor radiation at such high altitudes is still not well understood and more detailed observations will be needed, including near-infrared spectroscopy. (Spumy Pavel, et al; "Atmospheric Behavior and Extreme Beginning Heights of the Thirteen Brightest Photographic Leonid Meteors...," Meteoritics and Planetary Science, 35:243, 2000. Cr. R. Spaulding) Comment. As in SF#125, we must add that sounds are sometimes heard emanating from these anomalously high meteors, even though there is no air in which sound can he propagated. From Science Frontiers #133, JAN-FEB 2001 . 2001 William R. Corliss Other Sites of Interest SIS . Catastrophism, archaeoastronomy, ancient history, mythology and astronomy. Lobster . The journal of intelligence and political conspiracy (CIA, FBI, JFK, MI5, NSA, etc) Homeworking.com . Free resource for people thinking about working at home. ABC dating and personals . For people looking for relationships. Place your ad free. ...

... Science Frontiers ONLINE No. 104: Mar-Apr 1996 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects A METEORITIC EVENT LAYER IN ANTARCTIC ICE "Where the East Antarctic icesheet meets the Transantarctic Mountains, old, deep glacial ice is tilted upward and exposed. Within this visible cross section of the icesheet, layers of dark volcanic tephra serve as stratigraphic markers and datable age horizons. Systematic sampling of these layers at a well-known meteorite collection site (the Allan Hills Main Icefield) has revealed a band consisting of unusually dark and rounded particles, many of which are spheroidal. This debris layer (BIT-58) extends parallel to the stratigraphy of the ice established from the tephra bands, and thus apparently marks a single depositional event. Several kilograms of ice from two sites along this band were subsequently collected and melted, yielding a few grams of sediment for further study." Microscopic examination and microprobe analysis led to the following conclusions: "Although direct evidence of an extraterrestrial origin for this debris layer (such as the presence of cosmogenic 10 Be and 26Al) has not yet been obtained, the available data strongly suggest that this sediment originated as meteoritic spallation debris. This debris is distinct from other Antarctic 'cosmic dust' collections by virtue of its uniform, recognizable, ordinary chondrite composition and the consistent relation shown between grain size and texture. The BIT-58 layer probably originated from a single transient event, the passage and/or impact of a single large meteorite over the East Antarctic icesheet." (Harvey, ...

... off the moon by impacts of large asteroids there. (Kerr, Richard A.; "Earth Gains a Retinue of Mini-Asteroids," Science, 258: 403, 1992. Also: Mitton, Simon; "HouseSized Asteroids Home In on the Earth," New Scientist, p. 16, October 31, 1992.) Comet Smith-Tuttle. At a conference in Sydney last October, astronomer D. Steele announced that comet SmithTuttle is heading towards a possible impact with earth on August 14, 2116. This 3.1 -mile-diameter chunk of ice would have the destructive power of 20 million megatons (1 .6 million Hiroshima bombs). (Anonymous; "Astronomer Predicts Comet Collision," Baltimore Sun, October 26, 1992.) Some recent meteorite impacts. Turning from the dire consequences discussed above, just what sort of astronomical debris actually does hit the earth on a day-to-day basis? Fist-sized meteorites strike our planet about every two hours. These are the ones we read about in the newspapers; and they have left a surprisingly large legacy of damage to human structures. C. Spratt and S. Stephens, in a survey published in Mercury in 1992, listed 61 verified meteorite strikes since 1790 in which buildings and other human works were damaged. (Of course most fell harmlessly in the sea and unpopulated areas.) Spratt and Stephens also provide a table of 26 nearmisses of humans plus one confirmed human impact. At least one horse and a dog have been killed by meteorites. These lists make ...

... number of anomalous landforms on Mars can be attributed to glaciation, including the action of ice and meltwater. Glacial landscapes are concentrated south of lat -33 and in the Northern Plains suggesting vast Austral and Boreal ice sheets. Crater densities on the glaciated terrains indicate that the final glacial epoch occurred late in Martian history. Thus, Mars may have had a relatively warm, moist climate and dense atmosphere much later than previously believed." (Kargel, Jeffrey S., and Strom, Robert G.; "Ancient Glaciation on Mars," Geology, 20:3 , 1992.) If Mars was warm and wet not too long ago, as implied above, perhaps life did gain a foothold there through either independent invention or, perhaps, through seeding by template-carrying comets or meteorites. P.J . Boston et al have investigated one possible Martian ecosystem: "We have reexamined the question of extant microbial life on Mars in light of the most recent information about the planet and recently discovered nonphotosynthetic ecosystems on Earth -- deep sea hydrothermal vent communities and deep subsurface aquifer communities. On Mars, protected subsurface niches associated with hydrothermal activity could have continued to support life even after surface conditions became inhospitable. Geochemical evidence from the SNC meteorites and geomorphological evidence for recent volcanism suggest that such habitats could persist to the present time...We suggest a possible deep subsurface microbial ecology similar to those discovered to depths of several kilometers below the surface of the Earth." (Boston, Penelope J., et al; "On the Possibility of Chemosynthetic Ecosystems in Subsurface ...

... their similar geological characteristics and the presence of diagnostic and/or probable evidence of shock, these structures, once classified as 'crypto volcanic' or 'cryptoexplosion' structures, are more confidently ascribed to hypervelocity impact. No other similar occurrence of aligned features is known, and we calculate the probability of a chance alignment to be less than 10- 9 ." The craters are all roughly the same age: 310-330 million years. Rampino and Volk suspect they were formed all at once by a string of asteroids or comets. (Rampino, Michael R., and Volk, Tyler; "Multiple Impact Event in the Paleozoic: Collision with a String of Comets or Asteroids?" Geophysical Research Letters, 23:49, 1996) Comment. We cataloged a possible chain of meteorite scars in Argentina, near Rio Cuarto, in SF#80. Linear chain of known and probable impact structures across the North American Midwest. From Science Frontiers #105, MAY-JUN 1996 . 1996-2000 William R. Corliss ...

... 1992. Cr. H. DeKalb.) Rumors of a falling object. The landslide theory sounds good, but there have been rumors that another phenomenon was involved. B. Stein, of Orlando, has reported the testimony of a boater, who was far offshore at the time: ". .. the boater came forward with the information that, shortly before the time of the wave, he was in his boat about eight miles offshore. He watched as a distant object approached across the sky toward the ocean at a high rate of speed, and crossed the bow of his boat at an angle with a "whoosh" (his word). Shortly after, a giant swell made his 41-foot sailboat handle like a large surfboard. Various news sources state that the meteorite, as it is now being called, was anywhere from a meter to 10 feet across. The boater who wished to remain anonymous, gave the professors enough information so that they are hoping that the Navy will retrieve the object, which is presumed to be lying in about 70 feet of water off the Daytona Beach coastline, with plenty of coordinates for locating it." (Stein, Becky; "Daytona Beach MiniTidal wave," Louisiana Mounds Society Newsletter , no. 52, p. 2, October 1, 1992. Comment. With all the military and space-vehicle tracking equipment in the area, someone must know more about this event. From Science Frontiers #84, NOV-DEC 1992 . 1992-2000 William R. Corliss ...

... Science Frontiers ONLINE No. 80: Mar-Apr 1992 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Nullarbor Lode For the last few hundred years people have been picking up sparsely strewn meteorites all over the planet. But Antarctic explorers, within the last few decades, found that thousands of meteorites have been concentrated in the ice of the southernmost continent. Even more recently, the desolate, desert-like Nullarbor (" no-trees") Plain, in Southern Australia, has been discovered to be another concentrated source of of meteorites. There may be millions there. The problem is that only 2.9 % of them are iron meteorites, whereas those picked up in recent years around the planet-atlarge are 4.8 % irons. The meteorites from the Antarctic lode, on the other hand, weigh in with only 2.2 % irons. Why the marked differences? Could it be age? The Antarctic meteorites seem to be up to a million years old; those of Nullarbor, perhaps 16,000-18,000 years. (Anonymous; "A Meteorite Bounty from Down Under," Sky and Telescope, November 1991.) Comment. Perhaps pertinent is the observation that fossil meteorites are essentially nonexistent in geological formations older than a million years. This is an anomaly of itself! From Science Frontiers #80, MAR-APR 1992 . 1992-2000 William R. Corliss ...

... Science Frontiers ONLINE No. 68: Mar-Apr 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects New Life For Martian Life After the negative (some say "ambiguous") results from the Viking spacecraft life-detection experiments in 1976, astronomers and biologists have proclaimed that Mars is sterile. This pronouncement may have been premature. A meteorite discovered in Antarctica in 1979 may change a few minds on this matter. This particular meteorite is one of the handful thought to have been blasted off into space by an oblique impact of an asteroid on the surface of Mars. Somehow, statistics were kind to these tiny Martian orphans, for they found their ways to the Antarctic snows. But what is really exciting is the recent discovery that chemical analysis of one of these purported Martian meteorites revealed a high concentration of organic material deep within. The implication is that Martian life existed, perhaps still does exist, beneath the Martian surface, where the Viking Lander's scoop could not get at it. (Anonymous; "Life under Mars?" Sky and Telescope, 78:461, 1989.) Comment. In other words, Mars like the earth, may harbor an unappreciated fauna in crevicular structure beneath the environmentally rigorous surface. See also: SF#67. From Science Frontiers #68, MAR-APR 1990 . 1990-2000 William R. Corliss ...

... Science Frontiers ONLINE No. 73: Jan-Feb 1991 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Asteroid impact or volcanos?The debate over the real cause of the terrestrial catastrophism that occurred at the Cretaceous-Tertiary boundary, some 65 million years ago, grinds on. Some physical scientists claim rather imperiously that the dinosaurs and many other species were done in by the impact of a huge asteroid/meteorite. The worldwide iridium spike is conclusive, they say. Many paleontologists and geologists, however, remain unconvinced and prefer widespread volcanism. We have already covered the various arguments in past issues of Science Frontiers; here, we want to advise our readers that a pair of excellent articles by principals in this debate have appeared in Scientific American. Generally speaking, it seems that the proponents of the impact theory are now listening to the other side. For example, multiple impacts are now proposed to account for evidence of the type introduced below. (Alvarez, Walter, and Asaro, Frank; "An Extraterrestrial Impact," Scientific American, 263:78, October 1990. Also: Courtillot, Vincent E.; "A Volcanic Eruption," Scientific American, 263:85, October 1990.) A spike dulled. The case for a single asteroid/meteorite impact has been weakened by a recent reexamination of the classic exposure of the CretaceousTertiary boundary at Gubbio, Italy. Here, the discovery of an iridium "spike" at the boundary was thought to betoken a sudden, catastrophic, extraterrestrial event. On further ...

... Science Frontiers ONLINE No. 72: Nov-Dec 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Impact Crater Beneath Lake Huron "With the help of magnetic sensors, scientists have detected a rimmed circular structure, 30 miles in diameter, more than a mile beneath the floor of Lake Huron. They believe the magnetic ring marks a buried crater -- blasted by a meteorite at least 500 million years ago." (Stolzenburg, W.; "Impact Crater May Lie beneath Lake Huron," Science News, 138:133, 1990.) Reference. Many other impact craters are cataloged in section ESC in our catalog: Carolina Bays, Mima Mounds. Details on this book here . From Science Frontiers #72, NOV-DEC 1990 . 1990-2000 William R. Corliss ...

... Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Chemical surprises at the k-t boundary The presence of high iridium concentrations at the Cretaceous-Tertiary (K -T ) boundary, some 65 million years ago, has led to the widely accepted notion that an extraterrestrial projectile slammed into the earth at that time, wreaking geological and biological havoc. But the K-T boundary is anything but simple chemically and paleontologically. To illustrate, J.L . Bada and M. Zhao have found unusual amino acids in sediments laid down before and after this geological time marker. "They find that Danish sediments spanning the narrow boundary layer contain two amino acids, alpha-aminoisobutyric acid and isovaline, that are relatively uncommon in biological materials but abundant in the organicrich meteorites. They suggest that the body which collided with Earth 65 million years ago and left the telltale iridium residue may have been organic-rich, perhaps like a C-type asteroid or a comet. Such a possibility has interesting implications for the extinction and related atmospheric effects, and supports the idea that impact events could have supplied the Earth during a much earlier period with the raw materials for organic chemical evolution." Actually, the above quotation is pretty much in line with present mainstream thinking. Perhaps so, but Bada and Zhao identified two troubling anomalies. First, the amounts of amino acids found were surprisingly high. How could these complex molecules survive the searing temperatures engendered by high-velocity impact? Second, the amino acids may be abundant tens of centimeters above and below the ...

... Science Frontiers ONLINE No. 52: Jul-Aug 1987 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Meteorites Also Transport Organic Payloads Excerpts from the Abstract of a paper printed in Nature: "Much effort has been directed to analyses of organic compounds in carbonaceous chondrites because of their implications for orgainc chemical evolution and the origin of life. We have determined the isotopic composition of hydrogen, nitrogen and carbon in amino acid and monocarboxylic extracts from the Murchison meteorite. .. .. . "These results confirm the extraterrestrial origin of both classes of compounds, and provide the first evidence suggesting a direct relationship between the massive organo-synthesis occurring in interstellar clouds and the presence of pre-biotic compounds in primitive planetary bodies." (Epstein, S., et al; "Unusual Stable Isotope Ratios in Amino Acid and Carboxylic Acid Extracts from the Murchison Meteorite," Nature, 326:477, 1987.) From Science Frontiers #52, JUL-AUG 1987 . 1987-2000 William R. Corliss ...

... Science Frontiers ONLINE No. 58: Jul-Aug 1988 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Is the earth seeding the rest of the solar system?We begin with the lead paragraph from a recent letter to Nature from H.J . Melosh; "Recent evidence that the SNC meteorites originated on Mars raises the question of whether large impacts on Earth may eject rocks that could fall on Mars (or other planets in the Solar System) and, if so whether they might contain spores or some sort of viable microorganisms that would have the opportunity to colonize Mars." After some computations Melosh concludes: "It seems likely that the impacts that produced craters on Earth that are greater than 100 km in diameter would each have ejected millions of tons of near-surface rocks carrying viable microorganisms into interplanetary space, much in the form of boulders large enough to shield those organisms from ultraviolet radiation, low-energy cosmic rays, and even galactic cosmic rays. Under such circumstances spores might remain viable for long periods of time." (Melosh, H.J .; "The Rocky Road to Panspermia," Nature, 332:687, 1988.) Comment. Next we need a reasonable mechanism that spreads life through interstellar space. Light pressure, that's it; and the idea is over a century old! Incidentally, SNC is short for Shergottites, Nakhalites, Chassignites; all rare classes of meteorites. From Science Frontiers #58, JUL-AUG 1988 . 1988-2000 William R. Corliss ...

... deposit of iridium at the K-T (Cretaceous-Tertiary) boundary has been considered very strong evidence that a large astronomical object (asteroid or comet) devastated our planet some 65 million years ago. Some scientists, however, propose that the iridium layer was instead deposited through widespread volcanic activity. The proponents of an astronomical mechanism should be heartened by a recent paper in Nature, by W.S . Wolbach et al. Here is their Abstract: "Cretaceous-Tertiary (K -T ) boundary clays from five sites in Europe and New Zealand are 102 -104 -fold enriched in elemental C (mainly soot), which is isotopically uniform and apparently comes from a single global fire. The soot layer coincides with the Ir layer, suggesting that the fire was triggered by meteorite impact and began before the ejecta had settled." The composition of the hydrocarbons in the sediments points to the earth's biomass (mainly surface vegetation) as the source of the soot. The total quantity of K-T soot is equivalent to that which would be produced by burning 10% of all present terrestrial plant material. (Wolbach, Wendy S., et al; "Global Fire at the Cretaceous-Tertiary Boundary," Nature, 334:665, 1988.) Comment. Unmentioned in the above article is the possibility that extensive wildfires might have been generated by volcanic eruptions, perhaps accompanied by great electrical storms. The 1988 fires in Yellowstone needed no meteoric impact. Reference. Chemical anomalies in the earth's crust are cataloged in ESC1 in Anomalies in ...

... bombarded the planet early in its history. The models show that comets of moderate size would have slowed down enough during entry into the Earth's atmosphere for their organic component to survive the impact intact. .. .. . "The idea that comets supplied the Earth with the organic material needed to create life has been around for more than 20 years, but as often as some scientists have put forth the hypothesis, others have shot it down. "About 20% of comet nuclei are composed of organic matter, the rest ice and dust. Most of the organic component appears to be in a complex, polymerized form similar to kerogen, which is found in sedimentary rocks on Earth. From 4.33.7 billion years ago, during the period of heaviest bombardment by meteorites and comets, an estimated 1023 g of organic material would have been added to Earth by comet impacts had they made up 10% of the extraterrestrial flux. That is 1001000 times larger than most estimates of the photochemical production of the compounds over the same period." (Anonymous; "Comets and Life," Eos, no. 13, 1989.) Comment. Nowhere in the above article does one find the name of Fred Hoyle, whose ideas along these lines have been ridiculed for years. From Science Frontiers #63, MAY-JUN 1989 . 1989-2000 William R. Corliss ...

... Science Frontiers ONLINE No. 63: May-Jun 1989 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Life Currents In Space A few of the hundreds of meteorites picked up in the Antarctic wastes have chemical properties consistent with a Martian origin. Calculations, too, support the notion that a large meteoric impact could propel bits of the Martian surface into space where, statistically speaking, a tiny fraction would be captured by the earth's gravitational field. Some of these would fall to earth; others would remain in orbit. Now, the reverse scenario has been investigated numerically. S.A . Phinney and colleagues at the University of Arizona have calculated what would happen to small chunks of the earth's crust if a large meteor impact excavated a 60milewide crater. "Phinney's group used a computer to calculate where 1,000 particles would go if ejected from Earth in random directions, moving about 2.5 kilometers per second faster than the minimum speed necessary to escape. Of the 1,000 hypothetical particles, 291 hit Venus and 165 returned to Earth; 20 went to Mercury, 17 to Mars, 14 to Jupiter and 1 to Saturn. Another 492 left the solar system completely, primarily due to gravitational close encounters with either Jupiter or Mercury that 'slingshot' them on their way." (Eberhart, Jonathan; "Have Earth Rocks Gone to Mars?" Science News, 135:191, 1989.) Comment. One implication from the preceding analysis is that terrestrial bacteria and spores could well ...

... have identified four large basalt plateaus that might be terrestrial maria: "Notable examples of large lava plateaus that resemble lunar maria include, among others, the Deccan Plateau of India, the Columbia Plateau of western North America, the Parana Plateau of South America, and the Tungusska Basin of Siberia. All consist mostly of basalt lava flows; those on continents include minor quantities of rhyolite, and variable amounts of sediment. All seem to have appeared suddenly, within plates. No consistent context of plate interactions explains them. We suggest that large lava plateaus are indeed terrestrial maria." Alt et al go on to show that these lava plateaus seem to have initiated continental rifts and hotspot tracks where none existed before. A reasonable inference is that these plateaus are the consequence of the impacts of large meteorites. This is particularly the case with the Deccan Plateau, which is agedated as synchronous with the Cretaceous-Tertiary Boundary event, with its legacy of worldwide iridium deposits and the wholesale extinction of life. The paper concludes with: "It therefore appears that random encounters with vagrant asteroidal objects play an important role in setting the course of plate tectonic events. The earth does not control its own agenda." (Alt, D., et al; "Terrestrial Maria: The Origins of Large Basalt Plateaus, Hotspot Tracks and Spreading Ridges," Journal of Geology, 96:647, 1988.) From Science Frontiers #61, JAN-FEB 1989 . 1989-2000 William R. Corliss ...

... Science Frontiers ONLINE No. 59: Sep-Oct 1988 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Did an asteroid impact trigger the ice ages?Asteroids and comets are being blamed these days for more and more of our planet's catastrophism -- biological, meteorological, and geological. What a turnabout in scientific thinking in just a decade. F.T . Kyte et al have now provided additional details on meteoritic debris they first described in 1981. On the floor of the southeast Pacific, about 1400 kilometers west of Cape Horn, about 5 kilometers down, they found high concentrations of iridium in Upper Pliocene sediments about 2.3 million years old. Since the proposed projectile hit in very deep water, no crater was dug out. What did survive is called an "impact melt." This is debris rich in noble metals, such as iridium, and contains particles typical of a low-metal mesosiderite. Some 600 kilometers of the ocean floor received this debris. Kyte and his associates estimate the size of the impacting object at at least 0.5 kilometers in diameter. No biological extinctions are correlated with the 2.3 -million-year date, but there appears to have been a major deterioration of climate at about this time. There was a shift in the marine oxygen isotope records and, more obvious, the creation of the huge loess (sandy) deposits in China. What the impact may have done is to vaporize enough water into the atmosphere to increase the earth's albedo, ...

... Science Frontiers ONLINE No. 45: May-Jun 1986 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Disparity Between Asteroids And Meteorites Since the meteorites we pick up on earth (Antarctica and elsewhere) are thought to have come from pulverized asteroids, it is something of a shock to find profound dissimilarities between asteroids and meteorites. "The problem is that while reflectance spectra of some meteorites measured in the laboratory appear to correspond to spectra of various asteroids, the S class, which makes up about half of all asteroids in the inner belt, doesn't appear to match any common meteorite class, and conversely, common meteorite classes (e .g ., Ordinary Chondrites) appear to match only a few asteroids." (Harris, Alan W.; "Asteroid 29 Amphitrite Is a Topic of Interest," Geotimes, 30:25, June 1985.) Comment. Note that the visual meteors or shooting stars that burn up high in the atmosphere are believed to be cometary debris (SF#44) and mostly ice and dust. The meteors large and substantial enough to make it through the atmosphere and arrive at the surface as meteorites must have a different source -- something more palpable, such as the asteroids, but the spectral disparities reported above may force a reevaluation of this theory. From Science Frontiers #45, MAY-JUN 1986 . 1986-2000 William R. Corliss ...

... Science Frontiers ONLINE No. 45: May-Jun 1986 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Antarctic Meteorites Are Different The thousands of meteorites rescued from the Antarctic ice are markedly different from those collected elsewhere on our planet. First, the Antarctic collections contain rare types that seem to have come from the moon and perhaps Mars. Second, the trace elements in the Antarctic specimens differ substantially from those found elsewhere. Age is a third distinguishing parameter. The Antarctic specimens seem to have been residing on and in the ice for some 300,000 years. Almost all meteorites collected elsewhere are less than 200 years old, having been picked up soon after they fell. The implication is that those extraterrestrial projectiles that have accumulated in Antarctica had a different source. (Dennison, Jane E., et al; "Antarctic and non-Antarctic Meteorites Form Different Populations," Nature, 319:391, 1986.) Comment. A dedicated catastrophist would ask what extraterrestrial event occurred 300,000 years ago? Did it involve the moon? Was terrestrial life, including humans, affected? From Science Frontiers #45, MAY-JUN 1986 . 1986-2000 William R. Corliss ...

... Science Frontiers ONLINE No. 40: Jul-Aug 1985 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Libyan desert glass may not be the product of impacts.The mysterious Libyan Desert Glass (LDG) is almost pure silica. It occurs in pieces weighing up to 16 pounds in the Sand Sea of the Libyan desert, in an area roughly 130 by 53 kilometers. Most scientists have attributed it to meteorite impact. The results of a thermal, microstructural, and chemical analysis of LDG suggest that it is more likely derived from a low-temperature chemical process rather than meteorite impact on sand. (McPherson, D., et al; "Was Libyan Desert Glass (LDG) Formed by a Low Temperature Chemical Process?" Eos, 66:296, 1985.) Comment. This short abstract in Eos is frustrating. What sort of natural chemical process could leave pieces of glass strewn over such a huge area? And what about the Darwin Glass in Australia? Reference. Various natural glasses are discussed in ESM2 in the Catalog: Neglected Geological Anomalies. For more information on this book, visit: here . From Science Frontiers #40, JUL-AUG 1985 . 1985-2000 William R. Corliss ...

... nucleus, has long been considered a "dirty snowball"; that is, a mixture of dirt and ices. Now it appears that comets are more like "icy dirtballs"! And some of that dirt is pitch black. New measurments of the bare nuclei of comets, using a visual-infrared technique, find that the nuclei reflect as little as 2% of the incident sunlight. They are indeed charcoal black. Comet nuclei, according to W. Hartmann and his colleagues, are colored by a brownishblack primordial organic sludge, and have the appearance of "a very dark Hershey bar." The use of the adjective "organic" may be premature, but in light of the next item, maybe not. (2 ) Carbonaceous chondrites . This well-known class of meteorites sometimes appears tarry and is characterized by carbon contents of up to 2% and more. The Japanese have just reported the analysis of Yamoto 791198, a carbonaceous chondrite picked up in the Antarctic. This meteorite is loaded with amino acids, 20 kinds of them. These extraterrestrial amino acids are not considered biogenic because they are half left-handed and half right-handed; whereas all amino acids synthesized by terrestrial animals, plants, etc. are left-handed. [This is obviously presumptious because we have no notion how extraterrestrial life works, assuming it exists at all.] (3 ) The rings of Uranus . Voyager photos reveal that these rings are composed of unknown dark material quite unlike that in the high-albedo (bright) rings of Saturn. References. ( ...