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... Science Frontiers ONLINE No. 70: Jul-Aug 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects "TAIL WAGS DOG" IN SOLAR SYSTEM The Oort Cloud of comets hovering at the far frontiers of the solar system is, as we know from SF#57, not without its anomalies. Here, let us assume that it really does exist, even though we cannot see it. From a new book by I. Asimov (title below), we learn that this remote haze of icy fluff, the Oort Cloud, may really have about 90% of the angular momentum of the entire solar system. It was already sufficiently anomalous to discover that the planets possess fifty times the angular momentum of the much more massive sun. ... See ABB3 in The Sun and Solar System Debris.) Astronomers have been attempting for years to explain this 50:1 split. Now, with the Oort Cloud apparently having ten times the angular momentum of the planets, the situation is much worse. According to Asimov, the solar-system angular momentum is split as follows: Oort Cloud 90% All of the planets 9.8 % The sun 0.2 % The total mass of the Oort Cloud is estimated to be roughly that of Saturn. The recent flyby of Halley's Comet created this dilemma. It was discovered that Halley was a chunk containing 140 cubic miles of ice - much larger than anticipated for this "typical" comet. If the estimated 2 trillion comets are, on the average, Halley's ...
Terms matched: 2 - Score: 504 - 15 May 2017 - URL: /sf070/sf070a02.htm
... Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects A NEARBY RING OF COMETS?Some 589 long-period comets are known. They ply orbits around the sun that may take millions of years to complete. Astronomers are generally agreed that these bodies originate in a very distant (100,000 A.U .* ) halo of cometary material surrounding the entire solar system. J. Oort proposed this cloud, and it is named after him. Of course, we anomalists become wary when scientists "generally agree" on a hypothetical entity that no one can see. The Oort Cloud of comets, like the unseeable black holes, are given substance only by the effects they have on other solar-system denizens and seeable cosmic objects. But there may be another cloud of comets ... we can view directly. It is called the Kuiper Cloud (after G. Kui per). It is concentrated in the plane of the ecliptic just beyond the orbit of Neptune. Like the Oort Cloud, the Kuiper Cloud has not been seen yet, but we just might be able to with today's equipment! Its existence is hypothesized from the parameters of a different group of comets -- the so-called "short-period" comets, as exemplified by 76-year Halley's Comet. About 120 short-period comets have been discerned so far; and our computers now tell us that they cannot have originated in the Oort Cloud. Something closer and concentrated on the ecliptic is required. Thus the Kuiper Cloud or Belt was born. It is thought to ...
Terms matched: 2 - Score: 378 - 15 May 2017 - URL: /sf057/sf057a04.htm
... Science Frontiers ONLINE No. 69: May-Jun 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Mystery Of The Missing Comets A key feature of our solar system is the Oort Cloud of comets that surrounds the sun and its family of planets. No one has yet seen the Oort Cloud directly, but the textbooks say that it must be there. In fact, all stars like our sun with planetary systems should have their own private Oort Clouds of comets - if the prevailing theory of planetary-system formation is correct. When we see a comet looping around the sun, it is because it has been jostled loose from the Oort Cloud by a passing star or molecular cloud. Further, some of these jostled comets should be kicked ... and thus escape the solar system. Continuing with this reasoning, we on earth should sometimes see interstellar comets that have been shaken loose from other stellar systems. But we don't ! T.A . McGlynn and R.D . Chapman worry about this. "This lack of detections of extrasolar comets is becoming an embarrassment to the theories of solar system and comet formation." McGlynn and Chapman calculate that we should have seen six interstellar comets in the past 150 years, but the actual number is zero. Such interstellar comets would be easy to spot because they would be moving much faster than our own comets. Two possible explanations for the missing interstellar comets are: (1 ) The Oort Cloud theory is wrong; and (2 ) Solar systems like ours are rarer than ...
Terms matched: 2 - Score: 335 - 15 May 2017 - URL: /sf069/sf069a02.htm
... Science Frontiers ONLINE No. 50: Mar-Apr 1987 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Too many short-period comets Some comets, such as Halley's , have periods of less than 200 years. Scientists have postulated that these comets, which orbit relatively close to the sun, originally came from the far-distant Oort Cloud on parabolic (non-returning) orbits around the sun. Perturbations by the planets, notably Jupiter, deflected them into the tighter orbits we see today. The problem is that the number of parabolic comets entering the inner solar system from the Oort Cloud of comets (located at the outermost fringes of the solar system) is 100 times too small to account for the existing population of short ... period comets. M.E . Bailey believes this discrepancy can be removed if the Oort Cloud possesses a massive inner core of comets. (Bailey, M.E .; "The Near-Parabolic Flux and the Origin of Short-Period Comets," Nature, 324:350, 1986.) Reference. The Oort Cloud of comets is an entrenched part of astronomical dogma. For observations challenging its existence, see our catalog: The Sun and Solar System Debris. A description of this book may be found here . From Science Frontiers #50, MAR-APR 1987 . 1987-2000 William R. Corliss ...
Terms matched: 2 - Score: 301 - 15 May 2017 - URL: /sf050/sf050p06.htm
... Almost Critical Velocity ACB4 Sun-Grazing Comets: The Kreutz Group ACB5 Changing Cometary Periods ACB6 Jupiter's Family of Comets ACB7 Low-Eccentricity Cometary Orbits ACB8 The Scarcity of Hyperbolic Orbits ACB9 Cometary Groups ACB10 Orbits of New Comets Diverge from Common Point ACB11 Excess of Retrograde Long Period Comets ACB12 Uranus-Neptune Region Favored as Comet Source ACB13 Cometary Perturbations Suggestive of Planet X ACB14 Rapid Attrition of the Oort Cloud by Molecular Clouds ACB15 Dynamical Improbability of the Oort Cloud ACO OBSERVATIONAL ANOMALIES OF COMETS ACO1 Two-Dimensional Comet Tails ACO2 Cometary Activity Far from Solar Influence ACO3 Comets without Nuclei ACO4 Absence of Meteorites from Comet-Related Showers ACO5 Contraction of Cometary Comas as the Sun is Approached ACO6 Unexplained Abundance of Short-Period Comets ACO7 Persistence of Long-Period Comets Despite Attrition from Molecular Clouds ACO8 Seriality ... Cometary Apparitions ACO9 Multiple Tails and Antitails ACO10 Ejection of Spherical Halos ACO11 Correlation of Terrestrial Auroras and the Phenomena of Distant Comets ACO12 Blinking Comets ACO13 The Anomalous Disappearance of Comets ACO14 Anomalous Brightening of Short-Period Comets ACO15 Comet Reflectivities Are Similar to Those of Asteroids ACO16 Some Cometary Light Curves Resemble Those of Asteroids ACO17 New Comets Exhibit Different Brightening Behavior Than Old Comets ACO18 Anomalous Splitting of Comets ACO19 Tail-Wagging Comets ACO20 Cometary Outbursts ACO21 Comet Attrition Rates Imply Youth ACO22 No Ices in Cometary Reflection Spectra ACO23 The Blackness of Cometary Nuclei ACX OCCULTATIONS BY COMETS ACX1 Cometary Tails: Anomalous Occultations of Radio Stars AE ENIGMATIC OBJECTS AEO BRIGHT ENIGMATIC OBJECTS AEO1 Bright Objects near the Sun AEO2 Starlike Objects with Anomalous Motions AEO3 Unexplained Nebulous Objects AEX UNIDENTIFIED OBJECTS TRANSITING THE SUN, MOON, AND PLANETS AEX1 Objects Crossing ...
Terms matched: 2 - Score: 253 - 15 May 2017 - URL: /cat-astr.htm
... apparent 26- to 30-million-year periodicities of three terrestrial phenomena: Biological extinctions in the fossil record, Magnetic field reversals, and Terrestrial-crater ages. Could there be a connection between the clumped meteorite ages and these terrestrial phenomena? Perlmutter and Muller propose that all of these phenomena are the consequence of periodic storms of comets that invade the inner solar system from the direction of the Oort Cloud of comets that purportedly hovers at the fringe of the solar system. These comets not only devastate the earth but also collide with the asteroids, knocking off those bits and pieces we call meteorites. (Anonymous; "Do Meteorite Ages Tell of Comet Storms?" Astronomy, 17:12, January 1989.) Comment. Unanswered above is the question of why comet storms should be ... . One hypothesis is that Nemesis, the so-called Death Star, a dark companion of our sun, lurks out there, periodically nudging the Oort Cloud of comets, causing it to release some of its comets. From Science Frontiers #62, MAR-APR 1989 . 1989-2000 William R. Corliss ...
Terms matched: 2 - Score: 204 - 15 May 2017 - URL: /sf062/sf062a05.htm
... be more specific, some have claimed that large meteor craters come in clusters dated 28-31 million years apart. These catastrophic events have been correlated with biological extinctions, magnetic field reversals, and basalt flooding. The astronomical causes of this supposed periodicity range from the solar-system's crossing of the galactic plane, to the perturbations of an unseen solar companion, to regular perturbations of the Oort cloud of comets that is thought to hover at the fringe of the solar system. In short, a large, interlocking edifice of geological and astronomical speculation has been erected upon a foundation of terrestrial crater ages. But how well do we really know the ages of these craters? How complete is the cratering record? The answer to the first question is: "Not well at all. ... Further, we can be certain that many craters still lie undiscovered beneath sediments. In addition, most meteors/comets splashed into the oceans, leaving no record at all. An updating of the most recent crater data available, such as they are, greatly weakens the case for the popular 28-31 million-year period and strengthens support for a 19-22 million-year period. But neither cycle is in synchronism with the famous K-T (Cretaceous-Tertiary) Boundary, with its perplexing iridium layer and massive biological extinctions. In fact, say V.L . Sharpton et al, the entire known cratering record could well be the consequence of chance encounters between the earth and stray meteors and comets. Thus would pass the periodicities of this world! (Sharpton, ...
Terms matched: 2 - Score: 197 - 15 May 2017 - URL: /sf052/sf052g13.htm
... to detect the bursters in our neighboring galaxies -- but we do not! A more exciting suggestion is that gamma-ray bursters are really very close! This would be consistent with the failure to find cosmological redshifts in the burster spectra. Could they be really close, just a few hundred light away? Perhaps arranged in a spherical halo about our solar system in the vicinity of the postulated Oort Cloud of comets? If this were so, they would not have to be nearly as powerful as they would in the neutronstar model. If the gamma-ray bursters really do lurk just at the fringes of the solar system, they must, given their power and small size, be objects completely new to astronomy. (Schwarzschild; Bertram; "Compton Observatory Data Deepen the Gamma Ray ... Mystery," Physics Today, 45:21, February 1992.) Comment. Historically speaking, the gamma-ray bursters were discovered accidentally by satellites launched to detect surreptitious tests of nuclear weapons. Wouldn't it be ironical if our satellites are really monitoring artificial phenomena, generated by battles we can only write science fiction stories about? Reference. Refer to AOF29 in our Stars, Galaxies, Cosmos for gamma-ray "bursters." Details here . From Science Frontiers #83, SEP-OCT 1992 . 1992-2000 William R. Corliss ...
Terms matched: 2 - Score: 183 - 15 May 2017 - URL: /sf083/sf083a05.htm
... been invoked to explain the ups and downs of terrestrial biodiversity. R. Foot and Z. Silagadze propose that the 26-millionyear periodicity in terrestrial extinctions -- claimed to be present in the fossil record -- is due to a solar-system planet made of Mirror Matter (and therefore invisible). This postulated planet has a period of 26-million years and regularly gravitationally jostles the Oort Cloud of comets on the periphery of the solar system. These jolts unleash torrents of devastating comets upon the inner solar system every 26-million years, thereby blasting the earth and its sensitive biological cargo. This supposed Mirror-Matter planet happens to be the conceptual double of a Normal-Matter, hypothetical planet named Nemesis, which was proposed in the 1980s to account for the same periodical ... in the fossil record. However, diligent searches did not locate Nemesis. Of course, if Nemesis were made of Mirror Matter, as now proposed, it would have escaped telescopic detection then and would still elude our telescopes today! (Schilling, Govert; "Through the Looking Glass," New Scientist, p. 16, April 28, 2001.) Comment. Not only is a crater missing at the Tunguska site, but no one has been able to positively identify the immense impact crater that we suppose must have been excavated when untold numbers of tektites rained down upon Australia, Southeast Asia, and the Indian Ocean about 800,000 years ago. See item under GEOLOGY. From Science Frontiers #136, JUL-AUG 2001 . 2001 William R. Corliss Other Sites of ...
Terms matched: 2 - Score: 183 - 15 May 2017 - URL: /sf136/sf136p03.htm
