scholarly journals In search of historical roots of the extraterrestrial impact theory, II: two unknown German pioneers from the 1850s, Ludwig Pfeil and Karl Reichenbach

Author(s):  
Grzegorz Racki ◽  
Christian Koeberl ◽  
Michał Michalak

AbstractThe mid-nineteenth century is not regarded as the time when the theory of extraterrestrial catastrophism developed. However, two German scholars independently introduced original concepts of terrestrial impacts of large celestial bodies at that time. Ludwig Pfeil (1803–1896), a self-educated wealthy landowner, and Karl Reichenbach (1788–1869), an eminent scientist and industrialist, independently proposed in the 1850s that the Earth is an aggregate of meteoritic masses and has experienced many impact-induced cataclysms throughout its geological history. Until 1891, Pfeil analyzed the effects of the collision of a comet's gaseous body with Earth. He tried to simulate the effects of tsunami waves generated by impacts into the ocean and inferred the route of “cometary currents” from the morphology and orientation of coastlines and associated mountain ranges. Reichenbach speculated about fertilization of the terrestrial surface by extraterrestrial dust in the context of an accretionary origin for Earth that also manifested in meteoritic sources of volcanic extrusions. He linked the Mesozoic succession of “buried living worlds” to geological catastrophes, caused by successive meteorite impacts. These cosmic bombardment concepts were comprehensively criticized by contemporary researchers, but soon found many conceptual successors in the German-speaking science community. Therefore, Pfeil and Reichenbach should be regarded as pioneers of the impact theory.

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.


The unaided eye can see roundish dark spots on the Moon set in a brighter back­ground. Telescopic observation of these dark spots, called maria (plural of mare , sea) reveals that they are nearly level terrain sparsely covered with craters. The brighter surroundings or terrae are from shadow measurements found to be higher, some 1 to 3 km above the maria. The terra elevations scatter widely, reaching several kilometres in the mountain ranges. The most prominent of these ranges occur as peripheral mountain chains around the near-circular maria. Examples are the Apennines, the Alps, the Carpathians, and the Altai Scarp. These arcuate chains surround the maria as the crater walls surround crater floors, an analogy that can be carried further and implies, apart from scale, a similar origin. This origin is almost certainly impact by massive objects. In the case of the impact maria and pre-mare craters, the source of the objects appear to have been a satellite ring around the Earth through which the Moon swept very early in its history, in its outward journey from its position of origin very near the Earth (Kuiper 1954, 1965). The post-mare craters are presumably mostly asteroidal (and partly comet­ary) in origin and related to the craters observed by Mariner IV on Mars. The estimated time dependencies of these two crater-forming processes are shown schematically in figure 1. A fuller discussion of this problem has been given else­where (Kuiper, Strom & Poole 1966; Kuiper 1966). The higher asteroidal impact rate on Mars, by a factor of about 15, as derived from the Mariner IV records, is interpreted as being due to the greater proximity to the asteroid ring. The num­erical factor approximately agrees with theory. Mars apparently lacks the equiva­lent of the initial excessively intense bombardment of the Moon (attributed to impacts by circumterrestrial bodies); unless, of course, the entire Martian surface has been molten and is directly comparable to the lunar maria. This does not seem probable but can at present not be ruled out; if true, the earliest surface history would have been erased. The nature of the mare surface has, during the past decade, been an object of much, perhaps too much, speculation. With the several recent successful lunar reconnaissance missions completed, the older interpretation of the maria as lava beds, based on telescopic observation, has been abundantly confirmed. Four options discussed in recent literature are analysed in Kuiper (1965, §§A, B, pp. 12–39). Among the most potent arguments for the lava cover of the maria are the prominent lava flows observed on Mare Imbrium and Mare Serenitatis, each having a characteristic colour. A map of some Mare Imbrium flows is found in figure 2.


2011 ◽  
Vol 11 (11) ◽  
pp. 3013-3021
Author(s):  
E. Garbolino ◽  
P. Michel

Abstract. On a frequency, depending on their size, small celestial bodies enter into the Earth atmosphere and collide with our planet. On a daily basis, the size is likely to be about 20 cm, while for monthly events the largest it may be is about 1 m. The last significant witnessed event occurred in 1908 in the Siberian area of the Tunguska. The forest was devastated over an area of 2000 km2. According to recent estimates, this kind of event could occur with a frequency of one per hundred to thousand years. Since the last century, the demography and the urbanisation have significantly increased. Although the probability that such an event occurs over a populated area remains small, if this happened, it could cause significant damages (industrial, shopping centres, recreational places, etc.). From the analysis of the data on meteorites that have impacted the Earth, of the orbital and size properties of small threatening bodies as well as their potential impact outcome, this paper proposes a methodology to estimate the damage resulting from the impact of objects of given sizes. The considered sizes are up to the maximum threshold for local damages (less than a hundred metres in diameter) on some given territory. This approach is based on an initial definition phase of collision scenarios. Then, a second phase consisting of the accurate modelling of the territory, taking into account the land-use, the spatial distribution of the populations and goods, and the characterisation of the biophysical vulnerability of the stakes using thresholds of dangerous phenomena (overpressures). The third phase is related to the impact simulation on the territory, the estimation of the stakes potentially exposed and the costs of the destruction. The aim of this paper is to make a demonstration of principle, using as a study case the city of Nice that benefits from a complete database of infrastructures.


Author(s):  
Ian Woodfield

Joseph II’s failed scheme to swap the Austrian Low Countries for Bavaria provoked the formation of a league of states opposed to this reconfiguration of Europe. In order to repair the damage done to his reputation in the German-speaking world, he reinstated the recently disbanded Singspiel, so that it could compete with the Italian troupe. A lighthearted contest in the Orangerie at Schönbrunn inaugurated two years of intense operatic rivalry. Thanks to Dittersdorf’s hit success Der Apotheker, which overshadowed the impact of Figaro, the German party established an early ascendancy, but the Italians struck back with an opera featuring Spanish fashion. Martín y Soler’s Una cosa rara was greeted with storms of applause at its premiere on the name day of the fiancée of Archduke Franz, second in line to the Habsburg Monarchy.


2018 ◽  
Vol 39 (2) ◽  
pp. 145-161 ◽  
Author(s):  
Inês Freitas ◽  
Soumia Fahd ◽  
Guillermo Velo-Antón ◽  
Fernando Martínez-Freiría

Abstract The Maghreb region (North Africa) constitutes a major component of the Mediterranean Basin biodiversity hotspot. During the last centuries, a consistent human population growth has led to an unprecedented rate of habitat transformation and loss in the region and thus, threatening its biodiversity. The Western Mediterranean viper Vipera latastei-monticola inhabits humid and subhumid areas in the main mountain ranges of the Maghreb, facing such threatening factors; however, its elusive character and rarity hindered data collection for distinct biological purposes. Here, we study the biogeographical patterns and conservation status of the Maghrebian V. latastei-monticola resulting from recent sampling campaigns in Morocco and Tunisia. We update species distribution, and integrate phylogeographic and ecological niche modelling analyses at both species and lineage level to identify suitable areas, and to evaluate the impact of anthropogenic transformation and level of protection of their suitable space. We identified four highly divergent mitochondrial lineages, including a new lineage endemic to the Western High Atlas, with allopatric distributions and restricted to mountain ranges, supporting the role of mountains as past climatic refugia. Despite the remoteness of suitable areas, we report widespread habitat degradation and identify the low effectiveness of the current protected areas system in preserving the species and lineages range. Our study shows the urgent need to apply management actions for the long-term conservation of this vulnerable species and suggests a revaluation of the specific status of V. monticola, as these populations likely represent an ecotype of V. latastei.


Among the celestial bodies the sun is certainly the first which should attract our notice. It is a fountain of light that illuminates the world! it is the cause of that heat which main­tains the productive power of nature, and makes the earth a fit habitation for man! it is the central body of the planetary system; and what renders a knowledge of its nature still more interesting to us is, that the numberless stars which compose the universe, appear, by the strictest analogy, to be similar bodies. Their innate light is so intense, that it reaches the eye of the observer from the remotest regions of space, and forcibly claims his notice. Now, if we are convinced that an inquiry into the nature and properties of the sun is highly worthy of our notice, we may also with great satisfaction reflect on the considerable progress that has already been made in our knowledge of this eminent body. It would require a long detail to enumerate all the various discoveries which have been made on this subject; I shall, therefore, content myself with giving only the most capital of them.


2019 ◽  
Vol 28 (1) ◽  
pp. 180-190
Author(s):  
Ireneusz Wlodarczyk

AbstractWe computed the impact solutions of the potentially dangerous Near Earth Asteroid (NEA) 2001 BB16 based on 47 optical observations from January 20.08316 UTC, 2001, through February 09.15740 UTC, 2016, and one radar observation from January 19.90347 UTC, 2016. We used two methods to sample the starting Line of Variation (LOV). First method, called thereafter LOV1, with the uniform sampling of the LOV parameter, out to LOV = 5 computing 3000 virtual asteroids (VAs) on both sides of the LOV, which gives 6001 VAs and propagated their orbits to JD2525000.5 TDT=February 12, 2201. We computed the non-gravitational parameterA2=(34.55±7.38)·10–14 au/d2 for nominal orbit of 2001 BB16 and possible impacts with the Earth until 2201. For potential impact in 2195 we find A2=20.0·10−14 au/d2. With a positive value of A2, 2001 BB16 can be prograde rotator. Moreover, we computed Lyapunov Time (LT) for 2001 BB16, which for all VAs, has a mean value of about 25 y. We showed that impact solutions, including the calculated probability of a possible collision of a 2001 BB16 asteroid with the Earth depends on how to calculate and take into account the appropriate gravitational model, including the number of perturbing massive asteroids. In some complicated cases, it may depend also on the number of clones calculated for a given sigma LOV1. The second method of computing the impact solutions, called thereafter LOV2, is based on a non-uniformly sampling of the LOV. We showed that different methods of sampling the LOV can give different impact solutions, but all computed dates of possible impacts of the asteroid 2001 BB16 with the Earth occur in accordance at the end of the 22nd century.


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