A binary asteroid is a system of two asteroids orbiting their common center of mass. There have been detected in the Solar System numerous binary asteroids. About 15 percent of the scores of asteroids spotted around Earth are binary. When they hit the surface of a space body, they create paired impact craters.
In their article “Morphology and population of binary asteroid impact craters,” Katarina Miljković et al. claim that only 2 to 4 percent of craters on Earth have been identified as binary impacts, assuming that craters from the twin asteroids can easily overlap.
Computer simulations made by the teams proved that most binary asteroids hit the same spot and thus form a single crater.
Miljković suggested that the Chicxulub crater shows some important asymmetries and that it is worth considering whether it was formed by a binary asteroid.
4. A verneshot killed them off.
This theory claims that some of the supposed meteorite impact craters are actually craters from terrestrial activity.
A verneshot (named after the French science fiction writer Jules Verne) is a specific volcanic eruption caused by a massive superheated gas deep underneath the craton.
A craton is a large portion of a continental plate that has been relatively undisturbed since the Precambrian era. The term craton is used to distinguish the stable portion of the continental crust from regions that are more geologically active and unstable.
Morgan, Reston, and Ranero, scientists at Kiel University in Germany, published in Earth and Planetary Science Letters, in 2004, the article “Contemporaneous mass extinctions, continental flood basalts, and ‘impact signals’: are mantle plume-induced lithospheric gas explosions the causal link?” The team proposed the idea that a specific volcanic eruption triggered the K-Pg extinction.
The verneshot theory has been proposed as a causal mechanism which should explain the statistically unlikely contemporaneous occurrence of mass extinctions, continental flood basalts, and “impact signals” (shocked quartz, iridium, and other rare metals anomalies).
A verneshot is caused when a mantle plume comes in contact with a craton. Since the craton is structurally stronger, the plume cannot melt its way through. This causes the lava and gases to build up deep into the subsurface. If there are fractures in a continental rift zone, then some of the lava will travel along the fractures and erupt onto the surface creating the continental flood basalts, such as the Deccan Traps. When the pressure reaches an unbearable limit in the subsurface, then it causes a massive explosion, and the crater looks as if was made by a bolide impact. Gases, debris, and perhaps even a projectile would be thrown high into the atmosphere, and even into space orbit.
Such a specific volcanic gas explosion would fling enormous amounts of rock into the stratosphere and some large chunks could cause big impact craters when they fell back, explaining the coincidence of impacts and volcanic activity.
The release of gases and debris would have the necessary climatic effects on the environment to cause a mass extinction.
The verneshot theory has the advantage of explaining why the Chicxulub impact and continental flood basalts in India (the Deccan Traps) coincide, when the chances of both occurring simultaneously are very small.
Scientists noticed a correlation between massive, catastrophic continental flood basalt volcanism and huge craters that were previously thought to be caused by asteroid impacts.
The blast craters perhaps were buried by later flood basalts. Geophysical studies do show signs of circular features beneath both the Deccan and Siberian Traps.
Some researchers are proposing that the Yucatan impact was caused by a verneshot projectile, while a gas eruption took place at the Deccan Traps.
5. An asteroid caused a verneshot.
An asteroid, hitting Earth, could weaken specific spots of the craton and cause a verneshot. The impact crater and the verneshot explosion could be very far away or at the same site. The combined effects of the asteroid, super-heated gases (some of them poisonous), the falling rocks from the verneshot, and the prolonged dust clouds high in the skies are sufficient to cause the Cretaceous extinction.
Variation of this hypothesis states that the verneshots, not the impacts, were responsible for the mass extinctions.
6. Multiple impacts for a period of hundreds of thousands of years.
“A significant fraction of comets, however, should arrive in discrete showers triggered by a relatively close passage of a star or interstellar gas cloud. Early calculations indicated that such comet showers should last ~ 1 Myr,” wrote P. Hut, W. Alvarez, W. Elder, T. Hansen, E. Kauffman, G. Keller, E. Shoemaker, and P. Weissman in “Comet showers as a cause of mass extinctions,” published in Nature in 1987.
1 Myr stands for 1 million years.
Researchers have found signs of space bolides that hit at slightly different times about 65 million years ago, strengthening the gradualist idea.
According to Gerta Keller, a geologist and paleontologist at Princeton, strong evidence exists for three impacts at the end of the Cretaceous era, followed by climate shifts.
Sankar Chatterjee, a paleontologist at Texas Tech University states that evidence is accumulating that there were multiple bolide impacts across the K-Pg boundary such as the Chicxulub crater, the Shiva crater in India, the Boltysh crater in Ukraine, and Silverpit crater in the North Sea.
“The synchroneity of the Deccan Traps with the K-T boundary, their geographic proximity with the crater, and the occurrence of a thick shocked quartz layer below the lowermost lava flow strongly imply that the Deccan volcanism may have been triggered by the Shiva impact,” said Sankar Chatterjee.
Researchers have recently looked more favorably at the idea that bolides can travel in packs.
New finds may answer the criticism of the single-impact theory. Paleontologists had long noted that the fossil record of the late Cretaceous shows a slow decline of many life forms rather than a single vast die-off cosmic hit. That seemed inconsistent with an impact catastrophe. A series of impacts may have caused this slow decline.
Geologic clues that Keller and her colleagues are collecting from Mexico, Haiti, Guatemala, and Belize suggest that a barrage of space bodies hit the Earth over the course of 400,000 years. The first was the Chicxulub event, the second was a still-unlocated impactor at the end of the Cretaceous period, and then another one some 100,000 years later.
Kelley and Eugene Gurov of the Institute of Geological Sciences in Ukraine reported that seven samples of melted rock from the depths of the Boltysh crater yielded an average age of 65.2 million years.
”It’s so clear,” said Keller. “A tremendous amount of new data has been accumulated over the past few years that points in the direction of multiple impacts.” „Current evidence supports three impact events over a period of about 400,000 years.”
7. Volcano theory.
The Volcano-Greenhouse Gas Theory is considered the main alternative to the asteroid impact hypothesis.
It was created by Dewey McLean, professor of geology at Virginia Polytechnic Institute and State University. In 1979, he began linking the Cretaceous mass extinction with the Deccan Traps volcanism in India. This brought him into conflict with the team spearheaded by Luis Alvarez that was developing the asteroid theory at the same time. Bitingly critical of researchers who rejected his ideas, in a telephone interview Alvarez said: “I don’t like to say bad things about paleontologists, but they’re really not very good scientists. They’re more like stamp collectors.“
According to the Alvarez impact theory, the K-Pg boundary iridium enrichment was provided by an asteroid hitting the Earth. In 1981, McLean proposed that the Deccan Traps mantle plume volcanism released the boundary iridium from Earth’s core, which is rich in iridium too. Even today, the hotspot volcano that produced the Deccan Traps, Piton de la Fournaise on Reunion Island (French for Peak of the Furnace), is still releasing iridium.
Shocked quartz, an important part of the K-Pg boundary clay layer, is a hig
h pressure polymorph of quartz produced at, or close to, impact sites. It is produced under such high pressure that the only natural way it can form on Earth is by impacts of space bodies. Shocked quartz was discovered after underground nuclear bomb testing, which caused the intense pressures required to form shocked quartz.
Finding traces of shocked quartz in geological strata is a very good indicator of an impact or nuclear explosion.
Shocked quartz is found worldwide, in the thin Cretaceous–Paleogene boundary layer, and it is an important piece of evidence (in addition to iridium enrichment) that the transition between the two geological periods was caused by a massive impact.
Although geologists generally acknowledge that impacts would cause these fractures, some scientists suggest that they could also be the result of volcanic eruptions.
The basalt floods could have caused the K-Pg extinction through several mechanisms: release of dust and sulfuric aerosols into the air; blocking sunlight and thereby reduced photosynthesis; or carbon dioxide emissions increased the greenhouse effect when the dust and aerosols cleared from the atmosphere, causing global warming, ocean acidification, poisonous levels of sulfur and carbon dioxide, acid rains, etc.
The marine species in the oceans were killed off by warming and acidification of the upper waters as atmospheric carbon dioxide and sulfur diffused into them. Fossils revealed that marine species became smaller (the Lilliput effect) and less elaborate. Sulfur would have chemically bound with calcium, making that calcium unavailable in sufficient quantities to sea creatures that needed the element to build their shells and skeletons.
McLean suggested that the relatively high temperatures caused by the massive volcanism would have interfered with the reproduction of dinosaurs, eventually bringing about their extinction.
8. A series of asteroid impacts plus volcanoes.
Skeptics have long questioned whether an asteroid was solely responsible for the extinction. They proposed the theory that two separate extinctions finished off the dinosaur.
A Princeton press release of September, 2003, says, “Keller and a growing number of colleagues around the world are turning up evidence that, rather than a single event, an intensive period of volcanic eruptions as well as a series of asteroid impacts are likely to have stressed the world ecosystem to the breaking point. Although an asteroid or comet probably struck Earth at the time of the dinosaur extinction, it most likely was, as Keller says, ‘the straw that broke the camel’s back’ and not the sole cause.”
The advocates of this theory claim that the eruptions started 300,000 to 200,000 years before the asteroid impact, and they may have lasted about 100,000 years.
“The stuff living at the (ocean) bottom died out during the volcanic extinction event,” said Peter Ward.
Most of the land animals died off during the asteroid impacts.
The Deccan Traps are the impact site of an earlier huge meteor at least twice as wide as the Chicxulub asteroid. The evidence of the impact was submerged by upwelling lava.
Computer simulations indicate that once the meteor impact blew away the overlying rocks, the ones below, relieved of pressure, could then have turned to lava.
“The whole story is what happens underneath the crater,” said Adrian P. Jones, a geologist at University College London and lead author of the article that presented this extinction scenario.
“It’s rather like having a hot-air balloon and a pin. People have calculated the energy of the pin very accurately, but they’ve forgotten the balloon is going bang.”
Abbott and Isley report that their statistical analysis shows, with 97 percent confidence, that 9 out of 10 periods of heavy meteor bombardment corresponded to periods of massive volcanism.
9. Cantarell oil reservoir combustion.
Burnt oil and gas, not vegetation, caused the soot in the boundary layer at the end of the Cretaceous period.
Cantarell is a super-giant oil field in Mexico. It is by far the largest oil field in Mexico, and one of the largest in the world.
Cantarell comprises four major fields. The reservoirs were formed from carbonate breccia (rock consisting of angular fragments embedded in a finer matrix, formed by erosion, impact, volcanic activity, etc.) of the Late Cretaceous period, and this is the rubble from the asteroid impact that created the Chicxulub Crater.
In their article “Combustion of fossil organic matter at the Cretaceous-Paleogene (K-P) boundary,” published in 2008, Mark C. Harvey, Simon C. Brassell, Claire M. Belcher, and Alessandro Montanari suggested that the K-Pg mass extinction was caused by the combustion of Cantrell oil reservoir, resulting in greenhouse warming.
Claire Belcher and her colleagues at Royal Holloway University of London in Surrey, UK, wrote in a paper in the Proceedings of the National Academy of Sciences USA that the mixtures of carbon-based molecules in the soot don’t match those typically produced by burning vegetation; instead, they resemble those formed when hydrocarbons such as gas and oil are burnt.
The asteroid hitting the Earth created a supermassive Molotov cocktail (petrol bomb), ejecting into the atmosphere tremendous amounts of burning petroleum products. This should be registered with Guinness World Records as the largest and most lethal Molotov cocktail of all time.
10. Extraterrestrial contamination.
Alien genetic material caused the K-Pg mass extinction, accelerated hugely evolution, and disappeared at the right moment, exactly before becoming fatal to terrestrial life, just like vaccines.
The panspermia hypothesis holds that life on Earth was “seeded” from space. Life exists all around the space and is distributed throughout the Universe in the form of genetic material, germs, or spores. The constant transferral of viable organisms or genetic blocks between the space bodies by comets, space dust, and asteroids happens all the time.
According to Fred Hoyle and Wickramasinghe, cosmic genes are considered to be a driver of species evolution.
The extraterrestrial contamination idea as a cause of the Cretaceous extinction is hypothesized in the book Fred Hoyle’s Universe, presenting articles by various researchers, including Chandra Wickramasinghe and Max K. Wallis.
Wallis argues that the exotic amino acids in the K-Pg boundary zone are not extraterrestrial but an indicator of exotic pathogenic microfungi that flourished throughout this era. The genes coding for enzymes generating the amino acids arrived with the cometary dust containing microorganisms from space, perhaps as actual non-terrestrial fungi or as novel genes that incorporated into existing microfungi.
The new species of fungi with extraterrestrial genes were pathogenic to many Cretaceous organisms. They were particularly virulent because of their novel biochemical properties.
Their stress of massive introducing of extraterrestrial biota on the local fauna and flora caused not only mass extinction but also accelerated evolution. Species that evolved appropriate defense mechanisms survived the fungal attack.
The absence of “alien” fungi and exotic amino acids after the Cretaceous catastrophic events indicates that the exotic extraterrestrial biology lost the battle with the terrestrial organisms.
11. Artificial acceleration of evolution on Earth.
There were too many coincidences for a geologically short time, only a few tens of thousands of years: massive long-lasting volcanoes, prolonged heavy bolide bombardment of Earth, mighty injection with nonterrestrial genetic material or viable alien biota, etc. That has prompted some scholars to suggest that this was a deliberate control of the evolution on our planet via deliberate mass replacement of the fauna and the flora with higher species by some very advanced civilization.
The delivered extraterrestrial biological material could be naturally occurring in space, but it could also be artificial or genetically manipulated natural biota.
The larger idea is that our planet, the Solar System, the flora, the fauna, and the intelligence (or maybe the entire Universe—whatever it is) is under the strict control of a higher civilization, which for
some purpose is controlling the evolution of the biota and the intelligence.
All five big mass extinctions on Earth were followed by rapid and profound replacement of species with higher ones and accelerated evolution of the survivors.
12. Gaia control.
The Gaia hypothesis was formulated by James Lovelock in the 1960s, when he was employed by NASA as a part of a team aimed to detect life on Mars.
He suggested that all living and non-living parts of the Earth form a complex interacting system that can be considered as a single organism that has a regulatory effect on the Earth’s environment, flora, and fauna.
As a self-maintaining entity Gaia/Earth would possess an “immune system” to maintain its health and prosperity by affecting the global temperatures, ocean salinity, oxygen levels in the atmosphere, and many other environmental variables.
Lovelock suggests in his book The Revenge of Gaia that Gaia has many mechanisms for eliminating harmful species and civilizations through greenhouse gas emissions and global warming just as it did during the Permian and Cretaceous extinctions, killing off most of the flora and the fauna on the planet.
Gaia is constantly monitoring and controlling the replacement of the species on Earth. It has already replaced 99.99 percent of the species on our planet and it will continue to replace them. The life expectancy of the Universe is about 100 billion years, and in the future billions and billions of species and intelligences will originate and will be replaced by more advanced ones. The mass extinctions of animals, plants, and intelligent beings will continue under the control of Gaia.
Lovelock wrote, “The entire range of living matter on Earth from whales to viruses and from oaks to algae could be regarded as constituting a single living entity capable of maintaining the Earth’s atmosphere to suit its overall needs and endowed with faculties and powers far beyond those of its constituent parts... [Gaia can be defined] as a complex entity involving the Earth’s biosphere, atmosphere, oceans, and soil; the totality constituting a feedback of cybernetic systems which seeks an optimal physical and chemical environment for life on this planet.”
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