“A Perilous Journey” –Our Solar System Has Completed 20 Orbits of the Milky Way

Jan 27, 2020
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The Daily Galaxy
Posted on Jun 26, 2021 in Astronomy, Milky Way Galaxy, Science

milky way.jpg
An international team of astronomers discovered that the Milky Way’s disc of stars becomes increasingly ‘warped’ and twisted the further away the stars are from the galaxy’s center. “We usually think of spiral galaxies as being quite flat, like Andromeda which you can easily see through a telescope,” says Professor Richard de Grijs, an astronomer from Australia’s Macquarie University.

In 1999 astronomers focusing on a star at the center of the Milky Way, measured precisely how long it takes the sun to complete one orbit (a galactic year) of our home galaxy: 226 million years, bobbing our fraught journey through the disc of the Milky Way, drifting through ghostly spiral arms and the darkness of dense nebulae, keeping a constant 30,000 light years between Earth and the violent galactic core. The last time the sun was at that exact spot of its galactic orbit, Tyrannosaurus rex ruled the Earth.

Our orbit through the Milky Way is not a perfect circle or an ellipse, since the galaxy itself is a landscape of undulating concentrations of mass and complex gravitational fields. “None of the components of the galaxy are stationary,” writes Columbia University astrophysicist Caleb Scharf in The Copernicus Complex,” they, too, are orbiting and drifting in a three-dimensional ballet. The result is that our solar system, like billions of others, must inevitably encounter patches of interstellar space containing the thicker molecular gases and microscopic dust grains of nebulae. It takes tens of thousands to hundreds of thousands of years to pass through one of these regions.”

The Solar System is thought to have completed about 20–25 orbits during its lifetime or 0.0008 orbits since the origin of humans. When the last white embers of our Sun dim and die out billions of years from now, we will have completed approximately 60 orbits of our home galaxy.

It’s estimated that the Sun will continue fusing hydrogen for another 7 billion years. In other words, it only has another 31 orbits it can make before it runs out of fuel.

Our solar system undulates up and down through the midplane of the galactic disk, completing nearly three undulations per orbit around the Milky Way. Our Sun is currently located 56 light years above the galactic plane, but reaches vertical heights of more than 300 light years. It takes the Sun about 80 million years to undulate up and down, Meanwhile, older thick disk stars extend up to a few thousand light years above and below the midplane of our Galaxy.

As our Sun orbits the Milky Way and bobs up and down through the disk, the density of surrounding gas and dust changes drastically –regions where stars and gas are a little closer together than elsewhere in our galaxy’s disc.

Currently, the density of the interstellar medium in the local solar neighborhood is about one atom per cubic centimeter. However, when the Sun periodically passes through a molecular cloud every few hundred million years or so, the density rises to several hundred to several thousand atoms per cubic centimeter, with serious potential consequences here on Earth.

Researchers at Cardiff University suggests that our system’s orbit through the Milky Way encounters regular speedbumps – and by “speedbumps,” they mean “potentially mass-extinction-causing asteroids.”

Harvard astrophysicist Lisa Randall asks in her study “Dark Matter and the Dinosaurs: The Astounding Inteconnectedness of the Universe”: “Has Earth’s journey through the Milky Way Galaxy triggered mass-extinction events? If the solar system, as it orbited the center of the galaxy, were to move through the Milky Way’s dark-matter disk, Randall theorizes that the gravitational effects from the dark matter might be enough to dislodge comets and other objects from what’s known as the Oort Cloud and send them hurtling toward Earth. Randall suggests that “those oscillations occur approximately every 32-35 million years, a figure that is on par with evidence collected from impact craters suggesting that increases in meteor strikes occur over similar periods.”

The solar system now inhabits an unusually empty patch of space, the local bubble, with only one hydrogen atom per five cubic centimetres of space. In the past we must have drifted through much denser gas clouds, including some more than 100 light years across in whose cold and dark interiors hydrogen forms itself into molecules.

“This may happen only once every few hundred million years,” Scharf adds, “but if modern human civilization had kicked off during such an episode, we would have barely seen more than the nearest stars— certainly not the rest of our galaxy or the cosmos beyond. But could our planetary circumstances have been that different and still produced us? Would more changeable orbits in a planetary system, or bad weather, or passage through interstellar clouds, also thwart the emergence of life in some way?”

“So it’s a possibility,” Scharf observes, “that the planetary requirements for forming sentient life like us will necessarily always present the senses and minds of such creatures with a specific cosmic tableau, a common window onto the universe.”

If future research confirms a Milky Way galaxy-biodiversity link, it would force scientists to broaden their ideas about what can influence life on Earth. “Maybe it’s not just the climate and the tectonic events on Earth,” says University of Kentucky paleobiologist Bruce Lieberman. “Maybe we have to start thinking more about the extraterrestrial environment as well.”

“One of the key lessons gleaned from the study of the fossil record is that the physical environment has had a profound influence on evolution and extinction,” wrote Lieberman in an email to The Daily Galaxy. “As scientists have come to learn more and more about this topic, it is clear that our concept of the physical environment needs to extend beyond just considering the conditions on this planet, to instead also encompassing the conditions in the surrounding solar system and even the galaxy.”

“From asteroids to comets, and gamma ray bursts to supernovae, several important astronomical phenomena have played a major role in perturbing biodiversity on our planet,” continued Lieberman. “Indeed, in the case of some of these phenomena, we are only just beginning to understand the role they played. Other astronomical and astrophysical phenomena may have influenced evolution and extinction as well, though this needs to be explored in greater detail. It is definitely an exciting time to be studying how events and conditions within our galaxy may have influenced life on this planet.”

The Daily Galaxy, Maxwell Moe, astrophysicist, NASA Einstein Fellow, University of Arizona via Bruce Lieberman, Caleb Scharf,The Copernicus Complex, Cardiff University, and New Scientist
 
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A thought provoking article. Are there any correlations or relationships to the extinctions in the Paleozoic, Mesozoic, (other than the asteroid), and Cenozoic eras?
 
Jan 27, 2020
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A thought provoking article. Are there any correlations or relationships to the extinctions in the Paleozoic, Mesozoic, (other than the asteroid), and Cenozoic eras?
I've read M. S. Barash of the Shirshov Institute of Oceanology, Russian Academy of Sciences, pr. Nakhimovskii 36, Moscow, 117218 Russia, e􏰀mail: barashms@yandex.ru, who wrote extensively on the evidence for impacts found at the Permian-Triassic boundary (the PTB) resulting from the solar system's passage through the interstellar medium of varying densities in the Milky Way.

The reasons for the given associated geological periodicity are changes in the gravity potential of the Galaxy at differ􏰀ent distances from its center, variations in the rate of the Sun’s orbital motion, the Sun’s transit of the spiral arms of the Galaxy and the Sun's oscillations perpendicular to the galactic plane*.

The abrupt changes in the Earth's environmental conditions could have possibly been triggered by impacts of large asteroids or comets. The effect of impact events has only been proved recently. Material typical of impact events was encountered at the PTB in a number of rock sequences: shocked quartz in Antarctica and Australia and Fe–Ni–Si and Fe–Ni fragments and spherules and fullerenes with indicators of extraterres􏰀trial gases (3He) in China and Japan (the latter possi􏰀bly formed somewhat earlier).

According to Kaiho et al., noticeable variations in the values of 34S/32S and 87Sr/86Sr in Chinese rock sequences at the end of the Permian, along with high concentrations of impact minerals and a considerable reduction in the contents of Mn, P, Ca, and microfossils, prove the fall of an asteroid or a comet into the ocean, which caused a mas􏰀sive discharge of sulfur from the mantle to the ocean–atmosphere system. This led to a considerable decrease in the oxygen concentration, acid rainfalls, and an ongoing biotic crisis.

J. Théry et al. have presented data on the microspherules of a Cr/Ni􏰀spinel of cosmic origin in a number of rock sequences at the PTB, which was exactly determined based on micropaleontological data in Eastern Europe and the Caucasus region.

However, it is only in recent years that actual PTB craters have been discovered. Thus, evidence of the sediment 􏰀buried in the Bedout (Bedoo) impact struc􏰀ture was found on the northwestern continental mar􏰀gin of Australia 25 km away from the coast. Seismic and gravity surveys were conducted there, and two exploratory holes were drilled to the 3000 m depth. An impact breccia was discovered a few hundred meters thick with almost pure glass and disin􏰀tegrated plagioclase** grains. Just like in the Chicxulub crater, there is a central uplift typical of large astrob􏰀 lemes in the center of the crater 180–200 km in diam􏰀eter. Based on the plagioclase, the Ar/Ar age was esti􏰀mated at 250.1 ± 4.5 and 253 ± 5 Ma, which corre􏰀sponds to the PTB.

There are other known craters formed at the PTB. The Araguainha crater was discovered in Brazil (16.77° S, 52.98° W; 40 km in diameter) with an age of ~250 Ma. The 40 km wide Araguainha struc􏰀ture is the largest known crater in South America. The crater penetrates horizontally lying sediments of the basin of the Parana River in Central Brazil. The asteroid fell ~250 Myr ago. It had a diameter of 2–3 km and broke through the 2 km thick sediments exposing crystalline rocks of the basement on a 4 km wide territory. The central uplift 6–7 km wide and the circular trough are well􏰀defined topographically. The impact melt has a granite composition. During the Jurassic, the crater was filled in with sediments and basaltic lavas.

The Arganaty crater in Kazakhstan is referred to observed craters. It was discovered based on the results of satellite photography. The crater is located between lakes Balkhash and Sasykkol. The inner circle 60 km in diameter reflects the pediment levee of the crater. The diameter of the structure is up to 300– 315 km based on external arched faults. The circular rim is over 700 m high and 7.5–11.5 km wide. The crater and its circular structures are represented by sandy sediments underlied by granites in the central portion. The cosmogenic origin of the crater was confirmed by petrographic studies (shocked quartz) and the exist􏰀 ence of circular magnetic and gravity anomalies. There is an oval massif of leucocratic granites in the center of the structure under an unconsolidated sedi􏰀 ment cover. The author believes that a release of gran􏰀 ite magma from a deep focus was initiated by a cos􏰀 mogenic explosion. Based on combined geological
and geophysical data, the age of the crater corresponds to the PTB.

Inferred craters include the Falkland crater near the coast of Argentina (51° S, 60° W, 300 km in diam􏰀 eter, age 250 Ma). Less reliable craters are the follow􏰀 ing on the Siberian Platform: the Great Kuonamki (70° N, 111° E, diameter not available, age 251 Ma), the Gulinskii Massif (70.91° N, 101.2° E, over 50 km in diameter, age 251 Ma), the Essei (68.81° N, 102.18° E, 4.5 km in diameter, age 251 Ma), as well as the Alpian crater in Europe (43° N, 8° E, age ~250 Ma) and SAR 28 in Canada (56.57° N, 110.57° W, 7.5 km in diame􏰀ter, age ~250 Ma).

Numerous fragments of carbonaceous chondritic meteorites with characteristic geochemical indicators, shocked quartz, and extraterrestrial fullerenes with trapped 3He were discovered in argillite breccia of the PTB at Graphite Peak in the Central Trans􏰀Antarctic Moun􏰀tains near the Beardmore Glacier in Antarctica. Metallic grains were found similar to those encoun􏰀 tered in boundary layers in South China and Japan. The age was determined from the paleobotanic and isotopic data. The discovery confirms the occurrence of a global impact event.

Such an event might be the largest impact event in the Earth’s history that occurred in Wilkes Land, Ant􏰀arctica. A large negative magnetic anomaly was discovered there; it coincides with a circular topo􏰀graphic depression 243 km wide having a minimum depth of 848 m with the center being at 70° S, 120° E. In 2006, satellite gravity mapping detected a positive gravity anomaly reflecting a protuberance of ultrama􏰀 fic mantle rocks, which is typical of large impact cra􏰀ters. Subsurface radar mapping by NASA detected a 500 km crater located under the East Antarctic Ice Sheet. It is assumed to be a consequence of the impact of a 55 km asteroid that was 4–5 times greater than the Chicxulub asteroid (which led to the mass extinction of organisms 65 Myr ago). This impact caused the rise of a 200 km dome of mantle material. Based on the gravity data, this impact event occurred ~250 Myr ago. Along with the large Bedout impact event and others, this impact event probably was the most important reason for the sudden mass extinction of organisms at the PTB. No geological samples have been collected from under the ice sheet yet, and direct evidence is required to confirm the occurrence of the impact event. There are also other hypotheses regarding the origin of this structure: the formation of a mantle plume or the manifestation of different large􏰀scale volcanic activity.

The consequences of the impacts of large asteroids (even more so a number of them occurring within a short time interval) must have exerted a severely deleterious influence on marine and terrestrial organisms. With the sun's intensity already reduced due to cloud cover combined with aerosols, the Earth was stricken with sudden temperature deficits, acid rainfalls, and massive wild fires.

Evidence of the sediment 􏰀buried Bedout (Bedoo) impact struc􏰀ture was found on the northwestern continental mar􏰀gin of Australia 25 km away from the coast (18.18° S, 119.25° E) [9, 10]. Seismic and gravity surveys were conducted there, and two holes were drilled to the 3000 m depth. An impact breccia was discovered a few hundred meters thick with almost pure glass and disin􏰀 tegrated plagioclase grains. Just like in the Chicxulub crater, there is a central uplift typical of large astrob􏰀 lemes in the center of the crater 180–200 km in diam􏰀 eter. Based on the plagioclase, the Ar/Ar age was esti􏰀mated at 250.1 ± 4.5 and 253 ± 5 Ma, which corre􏰀sponds to the PTB.

Global expansion of dust clouds consisting of fragmented rock of the Earth’s crust thrown out of the crater
of the cosmic body weakened the photosynthesis and disturbed the entire food chain. The effect must have been strengthened by fires. The outburst of water vapor to the atmosphere when the asteroid fell to the ocean must have triggered a greenhouse effect. The impact of the asteroid on carbonate rocks with high contents of CaCO3 and CaSO4 resulted in an increase in the con􏰀tents of CO2 and sulfurous aerosols in the atmosphere. This must have led to acid rainfalls and a few degrees temperature increase.

According to Isozaki et al., changes in the geo􏰀 systems began ~265 Myr ago, when, after 50 Myr of the geomagnetic field’s stability, the Illawarra Reversal occurred. After it, a long period of frequent changes in the geomagnetic field began. This event caused by changes in the condition of the Earth’s nucleus and mantle manifested itself on the Earth’s surface as a series of the above􏰀 listed events.

Extraterrestrial cosmic causes probably triggered both changes in the Earth’s atmosphere and asteroid attacks. The influence of outer space on earthly pro􏰀cesses was suspected as early as in the first half of the 20th century (V.I. Vernadskii, A.L. Chizhevskii, M. Milankovich, etc) and has been studied since the mid􏰀-20th century. The influence of solar fluc􏰀tuations, the interaction of the Earth and the Moon, the Earth’s orbital revolution, and collisions of cosmic bodies—asteroids and comets—with the Earth were considered.

In the recent years, studies in this direc􏰀tion have been actively conducted. The reasons for the geological periodicity normally mentioned are changes in the gravity potential of the Galaxy at differ􏰀ent distances from its center, variations in the rate of the Sun’s orbital motion, the Sun’s transit of spiral arms of the Galaxy, its oscillations perpendicular to the galactic plane, etc.

The period of the Sun’s orbital motion in the Milky Way Gal􏰀axy (200–300 Myr) is compared to the duration of the geological eras. The time required to transit a galactic arm is 20–30 Myr, and the time during which the Solar system is exposed to the effect of galactic shock􏰀 (or pressure) waves is 4–5 Myr. These periodic intervals are associated with the boundaries between different 􏰀subdivisions of the stratigraphic scale of the Phanero􏰀zoic***. Geological and, primarily, paleontological changes occurring every 0.1–10 Myr can be explained either by collisions of large solitary asteroids a few kilometers in size with the Earth or by asteroid attacks—the fall of a series of asteroids to the Earth. It is suspected that the mortality of organisms and the activity of tectonic pro􏰀cesses abruptly increase when the Sun is in the regions of gas condensation and star formation within the galactic arms due to gravitational perturbations, increased cosmic rays and stellar explosions.

The estimates of the ages of the impact craters cor􏰀relate with the events of mass extinction of organisms. Mass extinctions have a periodicity of 26– 30 Myr, and the series of well􏰀dated impact craters has periodicities of 30 ± 0.5 and 35 ± 2 Myr. The above􏰀 mentioned cosmic phenomena of similar fre􏰀quency are suggested to explain this quasi􏰀periodicity. Regarding the mass extinctions of organisms, given that these events were sudden and short􏰀lived, they can only be explained by rapid disastrous changes in the ambient climate conditions caused by the impacts of large asteroids.

* The solar system also performs vertical oscillations relative to the disk. Since the potential is not Keplerian, the period of the vertical oscillations is different from the orbital period. Because mass is concentrated towards the galactic plane, the vertical motions depend primarily on the amount of mass in the disk. If one assumes a constant mass density ρm, then the frequency will be given by:
Ωv = 􏰃4πGρm.
More than two dozen estimates for ρm range from between 0.05 to 0.25 M⊙ pc−3, such that Ωv is not known accurately enough. Although it is not clear that averaging of the different results obtained in various methods is legitimate, it yields a half period (i.e., plane crossing intervals) of Pv/2 = 35±8 Myr (Matese et al., 1995), or even 37±4 Myr ( Stothers, 1998).

Estimates for the phase of this oscillation are better constrained. This is because we are near the galactic plane, having recently crossed it and now moving upwards, away from it. This implies that we last crossed the plane roughly before Tcross ≈ 0 − 5 Myr, based on the estimates of 1.5 ± 1.5 Myr (Bahcall and Bahcall, 1985, 5 ± 5 Myr (Rampino and Stothers, 1986) and 4 ± 2 Myr (Shoemaker and Wolfe, 1986).

At this periodicity, we should witnessed several effects. First, the stratified structure implies that the pressure closer to the center of the plane is higher. For the current amplitude, which is ∼ 100 pc, the pres- sure variations are ∼ 20%. This implies a heliopause which is typically 10% smaller.

Second, the vertical oscillations will also imply variations in the Cloud Radiative Feedback (CRF). The smaller source of variations originates from the varying size of the heliopause, thereby modulating the CRF. However, this effect is going to be of order ∼ 3% at the low energies which affect spallation, and negligible at the higher energies affecting tropospheric ionization. The larger variations in the CRF will come from the vertical stratification in the CRF distribution. Typical estimates for the CRF density give a 10% decrease over the 100 pc amplitude of the vertical oscillations (e.g., Boulares and Cox, 1990).

Third, passages through the galactic plane impose galactic tides which can perturb the Oort cloud. This, in turn, can send a larger flux of comets into the inner solar system (Torbett, 1986, Heisler and Tremaine, 1989), which can either hit directly (and leave a record as craters or cause mass extinction, Rampino and Stothers, 1984), or affect climate through disintegration in the atmosphere (Napier and Clube, 1979, Al- varez et al., 1980) or disintegrate and be accreted as dust (Hoyle and Wickramasinghe, 1978).

The Sun completes only about 3 vertical oscillations for every orbit around the Galactic centre.

See: http://old.phys.huji.ac.il/~shaviv/articles/ShavivChapter.pdf

** Paglioclase - a triclinic feldspar; especially : one having calcium or sodium in its composition.

*** Phanerozoic Eon is the current geologic eon in the geologic time scale. It is the one during which abundant animal and plant life has existed. It covers 541 million years to the present, and it began with the Cambrian Period when animals first developed hard shells preserved in the fossil record.

See: https://astronomy.stackexchange.com/questions/1997/what-mechanism-causes-oscillations-of-the-solar-systems-orbit-about-the-galacti

See: https://www.researchgate.net/publication/301301403_Mechanism_of_manganese_nodules_accumulation_and_their_maintenance_at_the_sediment_surface_Clarion-Clipperton_Province_the_Pacific

See: https://link.springer.com/article/10.1134/S000143701201002X?error=cookies_not_supported&code=00c489b6-a507-40a7-9ecf-cd513bc06329

See: https://www.researchgate.net/publication/233961301_Mass_Extinction_of_Ocean_Organisms_at_the_Paleozoic-MesozoicBoundary_Effects_and_Causes

It now appears that there is growing evidence to support the theory that the orbit of our Solar System through the Milky Way galaxy will intersect the pressure waves associated with the spiral arms and that, further, when these paths are crossed in oscillations perpendicular to the galactic plane, the interstellar medium of varying densities can dislodge comets from the Oort cloud and asteroids from the inner Solar System over time. The latter two items, it can now be seen with certainty, will have a rather deleterious effect on all the inhabitants of our planet.
Hartmann352
 
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I've read M. S. Barash of the Shirshov Institute of Oceanology, Russian Academy of Sciences, pr. Nakhimovskii 36, Moscow, 117218 Russia, e􏰀mail: barashms@yandex.ru, who wrote extensively on the evidence for impacts found at the Permian-Triassic boundary (the PTB) resulting from the solar system's passage through the interstellar medium of varying densities in the Milky Way.

The reasons for the given associated geological periodicity are changes in the gravity potential of the Galaxy at differ􏰀ent distances from its center, variations in the rate of the Sun’s orbital motion, the Sun’s transit of the spiral arms of the Galaxy and the Sun's oscillations perpendicular to the galactic plane*.

The abrupt changes in the Earth's environmental conditions could have possibly been triggered by impacts of large asteroids or comets. The effect of impact events has only been proved recently. Material typical of impact events was encountered at the PTB in a number of rock sequences: shocked quartz in Antarctica and Australia and Fe–Ni–Si and Fe–Ni fragments and spherules and fullerenes with indicators of extraterres􏰀trial gases (3He) in China and Japan (the latter possi􏰀bly formed somewhat earlier).

According to Kaiho et al., noticeable variations in the values of 34S/32S and 87Sr/86Sr in Chinese rock sequences at the end of the Permian, along with high concentrations of impact minerals and a considerable reduction in the contents of Mn, P, Ca, and microfossils, prove the fall of an asteroid or a comet into the ocean, which caused a mas􏰀sive discharge of sulfur from the mantle to the ocean–atmosphere system. This led to a considerable decrease in the oxygen concentration, acid rainfalls, and an ongoing biotic crisis.

J. Théry et al. have presented data on the microspherules of a Cr/Ni􏰀spinel of cosmic origin in a number of rock sequences at the PTB, which was exactly determined based on micropaleontological data in Eastern Europe and the Caucasus region.

However, it is only in recent years that actual PTB craters have been discovered. Thus, evidence of the sediment 􏰀buried in the Bedout (Bedoo) impact struc􏰀ture was found on the northwestern continental mar􏰀gin of Australia 25 km away from the coast. Seismic and gravity surveys were conducted there, and two exploratory holes were drilled to the 3000 m depth. An impact breccia was discovered a few hundred meters thick with almost pure glass and disin􏰀tegrated plagioclase** grains. Just like in the Chicxulub crater, there is a central uplift typical of large astrob􏰀 lemes in the center of the crater 180–200 km in diam􏰀eter. Based on the plagioclase, the Ar/Ar age was esti􏰀mated at 250.1 ± 4.5 and 253 ± 5 Ma, which corre􏰀sponds to the PTB.

There are other known craters formed at the PTB. The Araguainha crater was discovered in Brazil (16.77° S, 52.98° W; 40 km in diameter) with an age of ~250 Ma. The 40 km wide Araguainha struc􏰀ture is the largest known crater in South America. The crater penetrates horizontally lying sediments of the basin of the Parana River in Central Brazil. The asteroid fell ~250 Myr ago. It had a diameter of 2–3 km and broke through the 2 km thick sediments exposing crystalline rocks of the basement on a 4 km wide territory. The central uplift 6–7 km wide and the circular trough are well􏰀defined topographically. The impact melt has a granite composition. During the Jurassic, the crater was filled in with sediments and basaltic lavas.

The Arganaty crater in Kazakhstan is referred to observed craters. It was discovered based on the results of satellite photography. The crater is located between lakes Balkhash and Sasykkol. The inner circle 60 km in diameter reflects the pediment levee of the crater. The diameter of the structure is up to 300– 315 km based on external arched faults. The circular rim is over 700 m high and 7.5–11.5 km wide. The crater and its circular structures are represented by sandy sediments underlied by granites in the central portion. The cosmogenic origin of the crater was confirmed by petrographic studies (shocked quartz) and the exist􏰀 ence of circular magnetic and gravity anomalies. There is an oval massif of leucocratic granites in the center of the structure under an unconsolidated sedi􏰀 ment cover. The author believes that a release of gran􏰀 ite magma from a deep focus was initiated by a cos􏰀 mogenic explosion. Based on combined geological
and geophysical data, the age of the crater corresponds to the PTB.

Inferred craters include the Falkland crater near the coast of Argentina (51° S, 60° W, 300 km in diam􏰀 eter, age 250 Ma). Less reliable craters are the follow􏰀 ing on the Siberian Platform: the Great Kuonamki (70° N, 111° E, diameter not available, age 251 Ma), the Gulinskii Massif (70.91° N, 101.2° E, over 50 km in diameter, age 251 Ma), the Essei (68.81° N, 102.18° E, 4.5 km in diameter, age 251 Ma), as well as the Alpian crater in Europe (43° N, 8° E, age ~250 Ma) and SAR 28 in Canada (56.57° N, 110.57° W, 7.5 km in diame􏰀ter, age ~250 Ma).

Numerous fragments of carbonaceous chondritic meteorites with characteristic geochemical indicators, shocked quartz, and extraterrestrial fullerenes with trapped 3He were discovered in argillite breccia of the PTB at Graphite Peak in the Central Trans􏰀Antarctic Moun􏰀tains near the Beardmore Glacier in Antarctica. Metallic grains were found similar to those encoun􏰀 tered in boundary layers in South China and Japan. The age was determined from the paleobotanic and isotopic data. The discovery confirms the occurrence of a global impact event.

Such an event might be the largest impact event in the Earth’s history that occurred in Wilkes Land, Ant􏰀arctica. A large negative magnetic anomaly was discovered there; it coincides with a circular topo􏰀graphic depression 243 km wide having a minimum depth of 848 m with the center being at 70° S, 120° E. In 2006, satellite gravity mapping detected a positive gravity anomaly reflecting a protuberance of ultrama􏰀 fic mantle rocks, which is typical of large impact cra􏰀ters. Subsurface radar mapping by NASA detected a 500 km crater located under the East Antarctic Ice Sheet. It is assumed to be a consequence of the impact of a 55 km asteroid that was 4–5 times greater than the Chicxulub asteroid (which led to the mass extinction of organisms 65 Myr ago). This impact caused the rise of a 200 km dome of mantle material. Based on the gravity data, this impact event occurred ~250 Myr ago. Along with the large Bedout impact event and others, this impact event probably was the most important reason for the sudden mass extinction of organisms at the PTB. No geological samples have been collected from under the ice sheet yet, and direct evidence is required to confirm the occurrence of the impact event. There are also other hypotheses regarding the origin of this structure: the formation of a mantle plume or the manifestation of different large􏰀scale volcanic activity.

The consequences of the impacts of large asteroids (even more so a number of them occurring within a short time interval) must have exerted a severely deleterious influence on marine and terrestrial organisms. With the sun's intensity already reduced due to cloud cover combined with aerosols, the Earth was stricken with sudden temperature deficits, acid rainfalls, and massive wild fires.

Evidence of the sediment 􏰀buried Bedout (Bedoo) impact struc􏰀ture was found on the northwestern continental mar􏰀gin of Australia 25 km away from the coast (18.18° S, 119.25° E) [9, 10]. Seismic and gravity surveys were conducted there, and two holes were drilled to the 3000 m depth. An impact breccia was discovered a few hundred meters thick with almost pure glass and disin􏰀 tegrated plagioclase grains. Just like in the Chicxulub crater, there is a central uplift typical of large astrob􏰀 lemes in the center of the crater 180–200 km in diam􏰀 eter. Based on the plagioclase, the Ar/Ar age was esti􏰀mated at 250.1 ± 4.5 and 253 ± 5 Ma, which corre􏰀sponds to the PTB.

Global expansion of dust clouds consisting of fragmented rock of the Earth’s crust thrown out of the crater
of the cosmic body weakened the photosynthesis and disturbed the entire food chain. The effect must have been strengthened by fires. The outburst of water vapor to the atmosphere when the asteroid fell to the ocean must have triggered a greenhouse effect. The impact of the asteroid on carbonate rocks with high contents of CaCO3 and CaSO4 resulted in an increase in the con􏰀tents of CO2 and sulfurous aerosols in the atmosphere. This must have led to acid rainfalls and a few degrees temperature increase.

According to Isozaki et al., changes in the geo􏰀 systems began ~265 Myr ago, when, after 50 Myr of the geomagnetic field’s stability, the Illawarra Reversal occurred. After it, a long period of frequent changes in the geomagnetic field began. This event caused by changes in the condition of the Earth’s nucleus and mantle manifested itself on the Earth’s surface as a series of the above􏰀 listed events.

Extraterrestrial cosmic causes probably triggered both changes in the Earth’s atmosphere and asteroid attacks. The influence of outer space on earthly pro􏰀cesses was suspected as early as in the first half of the 20th century (V.I. Vernadskii, A.L. Chizhevskii, M. Milankovich, etc) and has been studied since the mid􏰀-20th century. The influence of solar fluc􏰀tuations, the interaction of the Earth and the Moon, the Earth’s orbital revolution, and collisions of cosmic bodies—asteroids and comets—with the Earth were considered.

In the recent years, studies in this direc􏰀tion have been actively conducted. The reasons for the geological periodicity normally mentioned are changes in the gravity potential of the Galaxy at differ􏰀ent distances from its center, variations in the rate of the Sun’s orbital motion, the Sun’s transit of spiral arms of the Galaxy, its oscillations perpendicular to the galactic plane, etc.

The period of the Sun’s orbital motion in the Milky Way Gal􏰀axy (200–300 Myr) is compared to the duration of the geological eras. The time required to transit a galactic arm is 20–30 Myr, and the time during which the Solar system is exposed to the effect of galactic shock􏰀 (or pressure) waves is 4–5 Myr. These periodic intervals are associated with the boundaries between different 􏰀subdivisions of the stratigraphic scale of the Phanero􏰀zoic***. Geological and, primarily, paleontological changes occurring every 0.1–10 Myr can be explained either by collisions of large solitary asteroids a few kilometers in size with the Earth or by asteroid attacks—the fall of a series of asteroids to the Earth. It is suspected that the mortality of organisms and the activity of tectonic pro􏰀cesses abruptly increase when the Sun is in the regions of gas condensation and star formation within the galactic arms due to gravitational perturbations, increased cosmic rays and stellar explosions.

The estimates of the ages of the impact craters cor􏰀relate with the events of mass extinction of organisms. Mass extinctions have a periodicity of 26– 30 Myr, and the series of well􏰀dated impact craters has periodicities of 30 ± 0.5 and 35 ± 2 Myr. The above􏰀 mentioned cosmic phenomena of similar fre􏰀quency are suggested to explain this quasi􏰀periodicity. Regarding the mass extinctions of organisms, given that these events were sudden and short􏰀lived, they can only be explained by rapid disastrous changes in the ambient climate conditions caused by the impacts of large asteroids.

* The solar system also performs vertical oscillations relative to the disk. Since the potential is not Keplerian, the period of the vertical oscillations is different from the orbital period. Because mass is concentrated towards the galactic plane, the vertical motions depend primarily on the amount of mass in the disk. If one assumes a constant mass density ρm, then the frequency will be given by:
Ωv = 􏰃4πGρm.
More than two dozen estimates for ρm range from between 0.05 to 0.25 M⊙ pc−3, such that Ωv is not known accurately enough. Although it is not clear that averaging of the different results obtained in various methods is legitimate, it yields a half period (i.e., plane crossing intervals) of Pv/2 = 35±8 Myr (Matese et al., 1995), or even 37±4 Myr ( Stothers, 1998).

Estimates for the phase of this oscillation are better constrained. This is because we are near the galactic plane, having recently crossed it and now moving upwards, away from it. This implies that we last crossed the plane roughly before Tcross ≈ 0 − 5 Myr, based on the estimates of 1.5 ± 1.5 Myr (Bahcall and Bahcall, 1985, 5 ± 5 Myr (Rampino and Stothers, 1986) and 4 ± 2 Myr (Shoemaker and Wolfe, 1986).

At this periodicity, we should witnessed several effects. First, the stratified structure implies that the pressure closer to the center of the plane is higher. For the current amplitude, which is ∼ 100 pc, the pres- sure variations are ∼ 20%. This implies a heliopause which is typically 10% smaller.

Second, the vertical oscillations will also imply variations in the Cloud Radiative Feedback (CRF). The smaller source of variations originates from the varying size of the heliopause, thereby modulating the CRF. However, this effect is going to be of order ∼ 3% at the low energies which affect spallation, and negligible at the higher energies affecting tropospheric ionization. The larger variations in the CRF will come from the vertical stratification in the CRF distribution. Typical estimates for the CRF density give a 10% decrease over the 100 pc amplitude of the vertical oscillations (e.g., Boulares and Cox, 1990).

Third, passages through the galactic plane impose galactic tides which can perturb the Oort cloud. This, in turn, can send a larger flux of comets into the inner solar system (Torbett, 1986, Heisler and Tremaine, 1989), which can either hit directly (and leave a record as craters or cause mass extinction, Rampino and Stothers, 1984), or affect climate through disintegration in the atmosphere (Napier and Clube, 1979, Al- varez et al., 1980) or disintegrate and be accreted as dust (Hoyle and Wickramasinghe, 1978).

The Sun completes only about 3 vertical oscillations for every orbit around the Galactic centre.

See: http://old.phys.huji.ac.il/~shaviv/articles/ShavivChapter.pdf

** Paglioclase - a triclinic feldspar; especially : one having calcium or sodium in its composition.

*** Phanerozoic Eon is the current geologic eon in the geologic time scale. It is the one during which abundant animal and plant life has existed. It covers 541 million years to the present, and it began with the Cambrian Period when animals first developed hard shells preserved in the fossil record.

See: https://astronomy.stackexchange.com/questions/1997/what-mechanism-causes-oscillations-of-the-solar-systems-orbit-about-the-galacti

See: https://www.researchgate.net/publication/301301403_Mechanism_of_manganese_nodules_accumulation_and_their_maintenance_at_the_sediment_surface_Clarion-Clipperton_Province_the_Pacific

See: https://link.springer.com/article/10.1134/S000143701201002X?error=cookies_not_supported&code=00c489b6-a507-40a7-9ecf-cd513bc06329

See: https://www.researchgate.net/publication/233961301_Mass_Extinction_of_Ocean_Organisms_at_the_Paleozoic-MesozoicBoundary_Effects_and_Causes

It now appears that there is growing evidence to support the theory that the orbit of our Solar System through the Milky Way galaxy will intersect the pressure waves associated with the spiral arms and that, further, when these paths are crossed in oscillations perpendicular to the galactic plane, the interstellar medium of varying densities can dislodge comets from the Oort cloud and asteroids from the inner Solar System over time. The latter two items, it can now be seen with certainty, will have a rather deleterious effect on all the inhabitants of our planet.
Hartmann352
Many Thanks for the data and references; I've got some big time reading to do.
 
Jan 27, 2020
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Many Thanks for the data and references; I've got some big time reading to do.
Many Thanks for the data and references; I've got some big time reading to do.
I don't know if you recall the huge ship named the Glomar Explorer? It was the ship Howard Hughes built for the CIA formerly known as the USNS Hughes Glomar Explorer (T-AG-193), which was a deep-sea drillship platform built for Project Azorian, the secret 1974 effort by the United States Central Intelligence Agency's Special Activities Division to recover the Soviet submarine K-129, which had a catastrophic accident and had sunk in the depths of the Pacific Ocean.

Interestingly, the Glomar Explorer's cover story* was that it was specifically built to retrieve Manganese nodules and other deep sea metal precipitates which had supposedly leached out of the sea water and lay on the sea floor where they could be "easily" harvested or mined, depending on your point of view.

Hughes told the media that the ship's purpose was to extract manganese nodules from the ocean floor. This marine geology cover story became surprisingly influential, causing many others from varying locales to examine the idea.

The mechanism, according to Max Semenovich Barash of the P.P. Shirshov Institute of Oceanology, is rather complicated but understandable: the manganese crust was formed in the Quaternary time. Micropaleontological complexes of Middle and Late Miocene, and Pliocene are present neither in the ancient clay, nor in the manganese crust, nor in Quaternary deposits containing mixed complexes of different ages. During that time the present erosion surface of the Late Oligocene clay was covered by younger deposits of the Late Oligocene, Miocene and Pliocene, which were eroded and washed away in the Quaternary. Probably the erosion begun about 0.9-0.7 million years ago at the beginning of “Glacial Pleistocene” when the ocean circulation, particularly when the near-bottom currents became more active.

The assumption was stated (Barash, Kruglikova, 1999, 2000), that the erosion of Tertiary deposits by near-bottom currents could be intensified by an effect of strong earthquakes in tectonically active zones which can be affective within several thousands of kilometers. In the water saturated non-consolidated medium of the ocean bottom the surface seismic Love and Rayleigh** waves should be propagated which can cause a vibration effect. The seismic vibration effect on the surface sediment layer must disintegrate and stir up sediments, which are then carried away by the bottom current. Large-size components of the sediment, including heavier manganese nodules, cannot be carried out by the current and form residual deposits. The same vibration effect causes ancient nodules to float up onto the surface of the Quaternary sediments.

This assumption was considered from the point of view of geophysical mechanisms (Kuzin, Barash, 2001, 2002a, 2002b). This new new approach was offered, which was based on mechanical influence on sediments of Rayleigh waves, generated by strongest (М7.5) earthquakes within the nearest Central American seismic active region. The proposed approach is based on data concerning of oscillations, which were excited by Rayleigh waves of some catastrophic earthquakes (for example, Lisbon, 1775, Assam, 1950, and Alaskan, 1964). These oscillations are observed at epicentral distances from 2000-4000 to 8000 km. The considered mechanism is realistic and allows the use of quantitative characteristics of Rayleigh wave amplitudes for the explanation of mechanical influence on sediments.

The study of Rayleigh wave amplitudes was carried out with the use of 200 records of earthquakes with M=6.0-8.2 at distances 560-9200 km for Petropavlovsk-Kamchatsky and North-Kurilsk seismic stations. For the analysis there were used data for various seismoactive regions of the Pacific Ocean. The close seismotectonic and seismic analogy between Kurile-Kamchatka and Central American segments of the Pacific belt allows us to apply the data recorded in the first region for study of same phenomena in the second one. Then for distances between investigated areas and the seismoactive Central American region of 3000-5400 km we have amplitudes of Rayleigh wave about 0.5 mm for single earthquake. The earthquakes with M = 7.5 – 8.5 can recure 20 times per 1000 years and capable to cause the “seismological erosion” of sediments up to 10 m/My but they are ineffective for manganese nodules movement, because of large dimensions (3-5 to 10 cm) of the nodules.

For the explanation of nodules movement it was necessary to use another mechanism. For the solution of this problem the mechanisms of near-bottom tsunami in the open ocean was used for the first time, which are excited by the same way as Rayleigh waves by the strongest (M7.5) earthquakes of the Central American seismic zone. It is known from observations near the California and in the Alaskan Bay, that these tsunami are propagated in the near-bottom water layer (at 3000-5000 m ocean depths) with amplitudes of 0.8-3.0 cm and velocities up to 180 m/s (Filloux, 1982; Milburn, Bernard, 1990). (Minutes of Ocean. Int. Conf. 20-23 April. St.Petersburg. VNIIOkeangeologia. 2002. P.55-57).

The mechanism of manganese nodules accumulation and their maintenance at the sediment surface show that such perturbations of the near-bottom water layer are capable of causing both the erosion of sediments and the transference (rolling, overturning) of manganese nodules over the ocean bottom. As a result they can occur on the surface of sediment of various ages. That confirms the supposition about the mechanisms of “floating-up” of massive manganese nodules or their maintenance on the bottom surface. This assumption suggests the reasons for the peculiarities of the Clarion-Clipperton zone, the regional stratigraphic hiatus, the formation of the residual nodule fields, and the maintenance of ancient nodules at the surface of the Quaternary deposits.

* Large areas of the deep sea floor are covered by manganese nodules, concretions which form around a seed of pure manganese and grow extremely slowly, but eventually reach the size of potatoes or larger. Nodules are composed of around 30% manganese, plus other valuable metals such as nickel, copper, and cobalt and even gold. There are estimated to be more than 21 billion tonnes of manganese nodules on the deep ocean floor (at depths of 4000 to 6000 meters), and their composition is richer than many of the ores from which the manganese they contain are usually extracted. Further, they're just lying about on the seabed. If you could figure out how to go down there and just scoop them up, you wouldn't have to dig mines, blast tremendous amounts of overburden away and process huge amounts of remaining rock.

As a result, the PR story was floated that Howard Hughes was setting out to mine the nodules on the Pacific Ocean floor, and that Glomar Explorer, built by Global Marine under contract for Hughes (operating, of course, as a cut-out for the CIA), would deploy a robotic mining barge called the Hughes Mining Barge 1 (HMB-1) which, when lowered to the ocean floor, would collect nodules, crush them, and send the slurry to the surface for processing on the mother ship.

This solved a great number of potential problems. Global Marine, as a publicly traded company, could simply (and truthfully) report that it was building Glomar Explorer under contract to Hughes, and had no participation in the speculative and risky mining venture, which would have invited scrutiny by Wall Street analysts and investors. Hughes, operating as the sole proprietorship of Hughes Tool Co. (ToolCo), was not required to disclose the source of the funds he was paying Global Marine. Everybody assumed the money was coming from Howard Hughes' vast personal fortune, which he had invested, over his career, in numerous risky ventures, when in fact, he was simply passing through money from a CIA black budget account on this caper. The HMB-1 was built by Lockheed Missiles and Space Company under contract from Hughes. Lockheed was involved in numerous classified U.S. government programs and had built the Lockheed Constellation four-engine airliner for Hughes when he was the sole owner of TWA, so operating in the same manner for the famously secretive Hughes raised few eyebrows. And it would all take place in international waters, far from any prying shore.

** Rayleigh waves - A type of seismic surface wave that moves with a rolling motion that consists of a combination of particle motion perpendicular and parallel to the main direction of wave propagation. The amplitude of this motion decreases with depth.

Love waves - A type of seismic surface wave in which particles move with a side-to-side motion perpendicular to the main propagation of the earthquake. The amplitude of this motion decreases with depth. Love waves cause the rocks they pass through to change in shape. They travel faster than Rayleigh waves. Love waves are named after their discoverer, British mathematician Augustus Love (1863-1940).

See: https://link.springer.com/article/10.1007/BF00367651

See: https://www.britannica.com/science/Rayleigh-wave

See: https://www.researchgate.net/publication/301301403_Mechanism_of_manganese_nodules_accumulation_and_their_maintenance_at_the_sediment_surface_Clarion-Clipperton_Province_the_Pacific

We come full circle in 1974 when we find Howard Hughes and the CIA working together under the cover story of the deep sea mining of the very manganese nodules deposited as a result of the erosion of the Tertiary deposits by swift near-bottom currents which are intensified by the effects of strong earthquakes in tectonically active zones. In the water saturated non-consolidated medium of the ocean bottom the surface seismic Love and Rayleigh waves are propagated which cause a further vibration effect. These seismic vibrations and their effects on the surface sediment layer where they stir up and disintegrate the sediments, which are then carried away by the bottom currents leaving the heavier manganese nodules which were to be "mined" by the Glomar Explorer instead of the planned raising of Soviet missile submarine K-129. Sometimes truth is stranger than physics.
Hartmann352
 
Nov 12, 2020
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Thanks. I remember both the situation and the incident when the Glomar Explorer retrieved the sunken Russian nuclear missile sub and ..... when one of those nuclear missiles slid out of the sub while near the surface, and plunged back into the ocean floor. A real "Oh Crap" moment. Fortunately there was no "flash, boom, bang". The remains of the sub's drowned crew were given an at sea burial with full military honors. Pictures of the crew's burial were given to the Soviet Embassy and the U.S. media got to publish the technology of story. The outcome of these events was improved U.S. / Soviet relations. Now a side note of snickering interest. At the time of Howard Hughes' involvement with the CIA, some local organized crime group attempted an extortion on the Hughes Organization. The gangsters were heartedly laughed at and shortly thereafter disappeared.
 
Jan 27, 2020
208
81
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Thanks. I remember both the situation and the incident when the Glomar Explorer retrieved the sunken Russian nuclear missile sub and ..... when one of those nuclear missiles slid out of the sub while near the surface, and plunged back into the ocean floor. A real "Oh Crap" moment. Fortunately there was no "flash, boom, bang". The remains of the sub's drowned crew were given an at sea burial with full military honors. Pictures of the crew's burial were given to the Soviet Embassy and the U.S. media got to publish the technology of story. The outcome of these events was improved U.S. / Soviet relations. Now a side note of snickering interest. At the time of Howard Hughes' involvement with the CIA, some local organized crime group attempted an extortion on the Hughes Organization. The gangsters were heartedly laughed at and shortly thereafter disappeared.
I'm waiting for the sea floors to be mined as that process would be far less ecologically destructive than strip mining.

My wife and I have often spoken about Hughes and how a few pills might have changed his life because he suffered from a serious form of OCD. A milder form enabled him to use his genius in engineering and movie production. If you haven't seen his magnum opus "Hell's Angels" from 1930 with Jean Harlow, I urge you to see it. For the time and even now, it is quite extraordinary.

I suspect that you have seen "The Aviator" with Leonardo DiCaprio as Hughes, if not, see it, especially for Hughes' appearance before Senator Owen Brewster of Maine's Senate Panel. I have seen the original newsreel of Hughes and DiCaprio is spot on in his portrayal and what he had to go through to prepare himself for the glare of the Klieg lights and the cameras.

As for the CIA, Hughes was the go to guy for the reasons I mentioned above. And Hughes had a great deal of clout in the DOD and the CIA.
Hartmann352
 
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