Artist's impression of a major impact event. The collision between a planet and an asteroid a few kilometers in diameter may release as much energy as several million nuclear weapons detonating simultaneously.

An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events (and exploding bolides) have been reported, with some occurrences causing deaths, injuries, property damage or other significant localised consequences.^[1] There have also been major impact events throughout Earth's history which severely disrupted the environment and caused mass extinctions.

Impact events have been a plot and background element in science fiction since knowledge of real impacts became established in the scientific mainstream.

Sizes and frequencies[link]

A bolide undergoing atmospheric entry

Small objects frequently collide with the Earth. There is an inverse relationship between the size of the object and the frequency that such objects hit the earth. The lunar cratering record shows that the frequency of impacts decreases as approximately the cube of the resulting crater's diameter, which is on average proportional to the diameter of the impactor.^[2] Asteroids with a 1 km (0.62 mi) diameter strike the Earth every 500,000 years on average.^[3] Large collisions – with 5 km (3 mi) objects – happen approximately once every ten million years. The last known impact of an object of 10 km (6 mi) or more in diameter was at the Cretaceous–Paleogene extinction event 65 million years ago.

Asteroids with diameters of 5 to 10 m (16 to 33 ft) enter the Earth's atmosphere approximately once per year, with as much energy as Little Boy, the atomic bomb dropped on Hiroshima, approximately 15 kilotonnes of TNT. These ordinarily explode in the upper atmosphere, and most or all of the solids are vaporized.^[4] Objects with diameters over 50 m (164 ft) strike the Earth approximately once every thousand years, producing explosions comparable to the one known to have detonated above Tunguska in 1908.^[5] At least one known asteroid with a diameter of over 1 km (0.62 mi), (29075) 1950 DA, has a possibility of colliding with Earth on March 16, 2880.

Objects with diameters smaller than 10 m (33 ft) are called meteoroids (or meteorites if they strike the ground). An estimated 500 meteorites reach the surface each year, but only 5 or 6 of these are typically recovered and made known to scientists.

Geology of impacts[link]

Earth has gone through periods of abrupt and catastrophic change, some due to the impact of large asteroids and comets on the planet. A few of these impacts may have caused massive climate change and the extinction of large numbers of plant and animal species.

The Moon is widely attributed to a huge impact early in Earth's history.  Impact events earlier in the history of Earth have been credited with creative as well as destructive events; it has been proposed that impacting comets delivered the Earth's water, and some have suggested that the origins of life may have been influenced by impacting objects by bringing organic chemicals or lifeforms to the Earth's surface, a theory known as exogenesis.

Eugene Merle Shoemaker was first to prove that meteorite impacts have affected the Earth.

These modified views of the Earth's history did not emerge until relatively recently, chiefly due to a lack of direct observations and the difficulty in recognizing the signs of an Earth impact because of erosion and weathering. Large-scale terrestrial impacts of the sort that produced the Barringer Crater, locally known as Meteor Crater, northeast of Flagstaff, Arizona, are rare. Instead, it was widely thought that cratering was the result of volcanism: the Barringer Crater, for example, was ascribed to a prehistoric volcanic explosion (not an unreasonable hypothesis, given that the volcanic San Francisco Peaks stand only 30 miles (48 km) to the west). Similarly, the craters on the surface of the Moon were ascribed to volcanism.

It was not until 1903–1905 that the Barringer Crater was correctly identified as being an impact crater, and it was not until as recently as 1963 that research by Eugene Merle Shoemaker conclusively proved this hypothesis. The findings of late 20th-century space exploration and the work of scientists such as Shoemaker demonstrated that impact cratering was by far the most widespread geological process at work on the solar system's solid bodies. Every surveyed solid body in the solar system was found to be cratered, and there was no reason to believe that the Earth had somehow escaped bombardment from space. In the last few decades of the twentieth century, a large number of highly modified impact craters began to be identified. The largest of these include Vredefort Crater, Sudbury Crater, Chicxulub Crater, and Manicouagan Crater. The first observation of a major impact event occurred in 1994: the collision of the comet Shoemaker-Levy 9 with Jupiter; to date, no such events have been observed on Earth.

Based on crater formation rates determined from the Earth's closest celestial partner, the Moon, astrogeologists have determined that during the last 600 million years, the Earth has been struck by 60 objects of a diameter of 5 km (3 mi) or more. The smallest of these impactors would release the equivalent of ten million megatons of TNT and leave a crater 95 km (60 mi) across. For comparison, the largest nuclear weapon ever detonated, the Tsar Bomba, had a yield of 50 megatons.

Besides direct effect of asteroid impacts on a planet's surface topography, global climate and life, recent studies have shown that several consecutive impacts can have effect on the dynamo mechanism at a planet's core responsible for maintaining the magnetic field of the planet, and can eventually shut down the planet's magnetic field.^[6]

While numerous impact craters have been confirmed on land or in the shallow seas over continental shelves, no impact craters in the deep ocean have been widely accepted by the scientific community^[7]. Impacts of projectiles as large as 1 km in diameter are generally thought to explode before reaching the sea floor, but it is unknown what would happen if a much larger impactor struck the deep ocean. The lack of a crater, however, does not mean that an ocean impact would not have dangerous implications for humanity. Some scholars have argued that an impact event in an ocean or sea may create a megatsunami (a giant wave), which can cause destruction both at sea and on land along the coast,^[8] but this is disputed.^[9]

Pleistocene impact events[link]

Aerial view of Barringer Crater in Arizona

In addition to the extremely large impacts that happen every few tens of millions of years, there are many smaller impacts that occur more frequently but which leave correspondingly smaller traces behind. Due to the strong forces of erosion at work on Earth, only relatively recent examples of these smaller impacts are known.

Artifacts recovered with tektites from the 803,000 year-old Australasian strewnfield event in Asia link a Homo Erectus population to a significant meteorite impact and its aftermath.^[10][11][12]

• the Rio Cuarto craters in Argentina, produced by an asteroid striking Earth at a very low angle, ~10,000 years old.
• the Lonar crater lake in India, which now has a flourishing semi-tropical jungle around it, ~52,000 years old (though a study published in 2010 gives a much greater age).
• the Henbury craters in Australia (~5,000 years old), and Kaali craters in Estonia (~2,700 years old), apparently produced by objects which broke up before impact.

The Younger Dryas impact event is a discredited hypothesis that an air burst from a purported comet above or even into the Laurentide Ice Sheet north of the Great Lakes set all of the North American continent ablaze around 12,900 years ago. The hypothesis attempts to explain the extinction of many of the large animals in North America and the unproven population decreases in the North American stone age Clovis culture about at the end of the Pleistocene epoch. Proponents claim the existence of a charred carbon-rich layer of soil found at some 50 Clovis-age sites across the continent.^[13] It has been criticized for not being consistent with paleoindian population estimates.^[14] Impact specialists have studied the claim and concluded that there never was such an impact, in particular because various physical signs of such an impact cannot be found.^[15]

Holocene impact events[link]

Trees knocked over by the Tunguska blast

The late Eugene Shoemaker of the U.S. Geological Survey came up with an estimate of the rate of Earth impacts, and suggested that an event about the size of the nuclear weapon that destroyed Hiroshima occurs about once a year. Such events would seem to be spectacularly obvious, but they generally go unnoticed for a number of reasons: the majority of the Earth's surface is covered by water; a good portion of the land surface is uninhabited; and the explosions generally occur at relatively high altitude, resulting in a huge flash and thunderclap but no real damage. Some have been observed. Noteworthy examples include the Sikhote-Alin Meteorite fall in Primorye, far eastern Russia, in 1947, and the Revelstoke fireball of 1965, which occurred over the snows of British Columbia, Canada.

Recorded impacts[link]

More recent prehistoric impacts are theorized by the Holocene Impact Working Group, including Dallas Abbott of Columbia University's Lamont-Doherty Earth Observatory.^[16] This group points to four enormous chevron sediment deposits at the southern end of Madagascar, containing deep-ocean microfossils fused with metals typically formed by cosmic impacts. All of the chevrons point toward a spot in the middle of the Indian Ocean corresponding with the newly hypothesized Burckle crater^[17] proposed to be some 29 km (18 mi) in diameter, or about 25 times larger than Barringer Crater. This group posits that a large asteroid or comet impact c. 2800-3000 BCE produced a mega-tsunami at least 180 m (590 ft) high, a catastrophic event that would have affected humanity's cradles of civilization.^[18] The evidence for the proposed crater has been challenged.^[19][20]

Presumed impact events during 533–534 ± 2 CE have been proposed by the dendrochronologist Mike Baillie as a possible cause of several brief (typically 5-10 year) climatic downturns recorded in ancient tree ring patterns. Bailliel highlights four such events and suggests that these might have been caused by the dust veils thrown up by the impact of cometary debris.^[21]

A Chinese record states that 10,000 people were killed in Shanxi Province in 1490 by a hail of "falling stones"; some astronomers hypothesize that this may describe the breakup of a large asteroid, although they find the number of deaths implausible.^[22]

Kamil Crater, discovered from Google Earth image review in Egypt, 45 meters in diameter, 10 meters deep is thought to have been formed less than 3,500 years ago in a then-unpopulated region of Western Egypt. It was found February 19, 2009 by V. de Michelle on a Google Earth image of the East Uweinat Desert, Egypt.^[23]

The Mahuika crater may have resulted from a modern impact event. The crater is located south of the Snares Islands (120 km (70 mi) southwest of Stewart Island) on the southern New Zealand shelf ^[24] and is approximately 20 kilometres (12 mi) wide. Material extracted from Siple Dome ice core melt water indicates that the impact occurred around 1443 C.E.

The Wabar craters in Arabia may have been created sometime during the past few hundred years.

A small number of meteor falls have been observed with automated cameras and recovered following calculation of the impact point. The first of these was the Pribram meteorite, which fell in Czechoslovakia (now the Czech Republic) in 1959.^[25] In this case, two cameras used to photograph meteors captured images of the fireball. The images were used both to determine the location of the stones on the ground and, more significantly, to calculate for the first time an accurate orbit for a recovered meteorite.

Following the Pribram fall, other nations established automated observing programs aimed at studying infalling meteorites. One of these was the Prairie Network, operated by the Smithsonian Astrophysical Observatory from 1963 to 1975 in the midwestern US. This program also observed a meteorite fall, the Lost City chondrite, allowing its recovery and a calculation of its orbit.^[26] Another program in Canada, the Meteorite Observation and Recovery Project, ran from 1971 to 1985. It too recovered a single meteorite, Innisfree, in 1977.^[27] Finally, observations by the European Fireball Network, a descendant of the original Czech program that recovered Pribram, led to the discovery and orbit calculations for the Neuschwanstein meteorite in 2002.^[28]

On August 10, 1972, a meteor which became known as The Great Daylight 1972 Fireball was witnessed by many people moving north over the Rocky Mountains from the U.S. Southwest to Canada. It was filmed by a tourist at the Grand Teton National Park in Wyoming with an 8-millimeter color movie camera.^[29] The object was in the range of size from a car to a house and could have ended its life in a Hiroshima-sized blast, but there was never any explosion. Analysis of the trajectory indicated that it never came much lower than 58 km (36 mi) off the ground, and the conclusion was that it had grazed Earth's atmosphere for about 100 seconds, then skipped back out of the atmosphere to return to its orbit around the Sun.

On November 21, 2009, a fireball was sighted in South Africa by police and traffic cameras. The probable meteor may have landed in a remote area on the Botswana border, and likely made little impact.^[30]

Many impact events occur without being observed by anyone on the ground. Between 1975 and 1992, American missile early warning satellites picked up 136 major explosions in the upper atmosphere. In the November 21, 2002, edition of the journal Nature, Peter Brown of the University of Western Ontario reported on his study of U.S. early warning satellite records for the proceeding 8 years. He identified 300 flashes caused by 1 to 10 m (3 to 33 ft) sized meteors in that time period and estimated the rate of Tunguska-sized events as once in 400 years.^[31] Eugene Shoemaker estimated that one of such magnitude occurs about once every 300 years, though more recent analyses have suggested he exaggerated by an order of magnitude.

Modern impacts[link]

One of the best-known recorded impacts in modern times was the Tunguska event, which occurred in Siberia, Russia, in 1908. This incident involved an explosion that was probably caused by the airburst of an asteroid or comet 5 to 10 km (3.1 to 6.2 mi) above the Earth's surface, felling an estimated 80 million trees over 2,150 km² (830 sq mi).

The first known modern strike to a human was on the 28'th of April 1927 in Aba, Japan, to the head of the five-year-old daughter of Mrs. Kuriyama; a bean-sized stone was found resting on her headband and now resides in a museum, called the Aba stone.^[32]

The first known modern case of a human injured by a space rock occurred on November 30, 1954, in Sylacauga, Alabama.^[33] There a 4 kg (8.8 lb) stone chondrite crashed through a roof and hit Ann Hodges in her living room after it bounced off her radio. She was badly bruised. Several persons have since claimed to have been struck by 'meteorites' but no verifiable meteorites have resulted.

In 1913 A ship was reported to have been struck and damaged by a meteorite while sailing between Sydney and South America. ^[34]

On September 15, 2007, a chondritic meteor crashed near the village of Carancas in southeastern Peru near Lake Titicaca, leaving a water-filled hole and spewing gases across the surrounding area. Many residents became ill, apparently from the noxious gases shortly after the impact.

In the dark morning hours of January 18, 2000, a fireball exploded over the city of Whitehorse in the Canadian Yukon at an altitude of about 26 km (16 mi), lighting up the night like day. The meteor that produced the fireball was estimated to be about 4.6 m (15 ft) in diameter and with a weight of 180 tonnes. This blast was also featured on The Science Channel series Killer Asteroids, with several witness reports from residents in Atlin, British Columbia.

Comet Shoemaker-Levy 9's scar on Jupiter (dark area near Jupiter's limb)

A picture of the Jupiter 2009 impact event blemish captured by the Keck II telescope and its near-infrared camera at Mauna Kea Observatory, on July 20.

A meteor was observed striking Reisadalen in Nordreisa municipality in Troms County, Norway, on June 7, 2006. Although initial witness reports stated that the resultant fireball was equivalent to the Hiroshima nuclear explosion, scientific analysis places the force of the blast at anywhere from 100-500 tonnes TNT equivalent – around 3% of Hiroshima's yield.^[35]

Impact caused extinction events[link]

In the past 540 million years there have been five generally-accepted, major mass extinctions that on average extinguished half of all species.  One of the largest mass extinction to have affected life on Earth was in the Permian-Triassic, which ended the Permian period 250 million years ago and killed off 90% of all species;^[36] life on Earth took 30 million years to recover.^[37] The cause of the Permian-Triassic extinction is still matter of debate with the age and origin of proposed impact craters, i.e. the Bedout High structure, hypothesized to be associated with it are still controversial.^[38] The last such mass extinction led to the demise of the dinosaurs and coincided with a large meteorite impact; this is the Cretaceous–Paleogene extinction event (also known as the K–T or K–Pg extinction event); This occurred 65 million years ago. There is no definitive evidence of impacts leading to the three other major mass extinctions.

In 1980, physicist Luis Alvarez; his son, geologist Walter Alvarez; and nuclear chemists Frank Asaro and Helen V. Michael from the University of California, Berkeley discovered unusually high concentrations of iridium in a specific layer of rock strata in the Earth's crust. Iridium is an element that is rare on Earth but relatively abundant in many meteorites. From the amount and distribution of iridium present in the 65-million-year-old "iridium layer", the Alvarez team later estimated that an asteroid of 10 to 14 km (6 to 9 mi) must have collided with the earth. This iridium layer at the Cretaceous–Paleogene boundary has been found worldwide at 100 different sites. Multidirectionally shocked quartz (coesite), which is only known to form as the result of large impacts or atomic bomb explosions, has also been found in the same layer at more than 30 sites. Soot and ash at levels tens of thousands times normal levels were found with the above.

Anomalies in chromium isotopic ratios found within the K-T boundary layer strongly support the impact theory.^[39] Chromium isotopic ratios are homogeneous within the earth, therefore these isotopic anomalies exclude a volcanic origin which was also proposed as a cause for the iridium enrichment. Furthermore the chromium isotopic ratios measured in the K-T boundary are similar to the chromium isotopic ratios found in carbonaceous chondrites. Thus a probable candidate for the impactor is a carbonaceous asteroid but also a comet is possible because comets are assumed to consist of material similar to carbonaceous chondrites.

Probably the most convincing evidence for a worldwide catastrophe was the discovery of the crater which has since been named Chicxulub Crater. This crater is centered on the Yucatán Peninsula of Mexico and was discovered by Tony Camargo and Glen Pentfield while working as geophysicists for the Mexican oil company PEMEX. What they reported as a circular feature later turned out to be a crater estimated to be 180 km (110 mi) in diameter. Other researchers would later find that the end-Cretaceous extinction event that wiped out the dinosaurs had lasted for thousands of years instead of millions of years as had previously been thought.^{[citation needed]} This convinced the vast majority of scientists that this extinction resulted from a point event that is most probably an extraterrestrial impact and not from increased volcanism and climate change (which would spread its main effect over a much longer time period).

Recently, several proposed craters around the world have been dated to approximately the same age as Chicxulub — for example, the Silverpit crater in the United Kingdom, the Boltysh crater in Ukraine and the Shiva crater near India. This has led to the suggestion that the Chicxulub impact was one of several that occurred almost simultaneously, perhaps due to a disrupted comet impacting the Earth in a similar manner to the collision of Comet Shoemaker-Levy 9 with Jupiter in 1994.

It was the lack of high concentrations of iridium and shocked quartz which has prevented the acceptance of the idea that the Permian extinction was also caused by an impact. During the late Permian all the continents were combined into one supercontinent named Pangaea and all the oceans formed one superocean, Panthalassa. If an impact occurred in the ocean and not on land at all, then there would be little shocked quartz released (since oceanic crust has relatively little silica) and much less material.

Although there is now general agreement that there was a huge impact at the end of the Cretaceous that led to the iridium enrichment of the K-T boundary layer, remnants have been found of other impacts of the same order of magnitude that did not result in any mass extinctions, and there is no clear linkage between an impact and any other incident of mass extinction. Nonetheless it is now widely believed that mass extinctions due to impacts are an occasional event in the history of Earth^{[citation needed]}.

Paleontologists David M. Raup and Jack Sepkoski have proposed that an extinction occurs roughly every 26 million years (though many are relatively minor). This led physicist Richard A. Muller to suggest that these extinctions could be due to a hypothetical companion star to the Sun called Nemesis periodically disrupting the orbits of comets in the Oort cloud, and leading to a large increase in the number of comets reaching the inner solar system where they might hit Earth.

Indeed, in the early history of the Earth (about four billion years ago) bolide impacts were almost certainly common since the solar system contained far more discrete bodies than at present. Such impacts could have included strikes by asteroids hundreds of kilometers in diameter, with explosions so powerful that they vaporized all the Earth's oceans. It was not until this heavy bombardment slackened that life appears to have begun to evolve on Earth. If such an impact were to occur on Earth today, it is an almost certainty that human civilization would be wiped out. Fortunately, our solar system is much less populated with large objects today and the probability of such an event happening is essentially zero, as the larger asteroids in the asteroid belt and the giant comets in the Kuiper belt that are in this size range are in stable orbits that will not enter the inner solar system, let alone intersect the orbit of Earth, with no observed exceptions.^{[citation needed]}

The leading theory of the Moon's origin is the giant impact theory, which states that Earth was once hit by a planetoid the size of Mars; if this theory holds then that impact was almost certainly the largest hit Earth ever suffered. Peculiarities in the rotation and inclination of the planets, such as Venus' retrograde rotation and the extreme tilt of Uranus' axis, are thought to be the consequence of other such giant impacts, as the current hypotheses of solar system and planetary formation, in absence of impact, could not account for the large transfers of momentum that we clearly see evidence for today, in Venus and Uranus for example.

Non-terrestrial impacts[link]

The 1994 impact of Comet Shoemaker-Levy 9 with Jupiter served as a "wake-up call", and astronomers responded by starting programs such as Lincoln Near-Earth Asteroid Research (LINEAR), Near-Earth Asteroid Tracking (NEAT), Lowell Observatory Near-Earth Object Search (LONEOS) and several others which have drastically increased the rate of asteroid discovery.

In 1998, two comets were observed plunging into the Sun in close succession. The first of these was on June 1 and the second the next day. A video of this, followed by a dramatic ejection of solar gas (supposedly unrelated to the impacts), can be found at the NASA^[40] website. Both of these comets evaporated before coming into contact with the surface of the Sun. According to a theory by NASA Jet Propulsion Laboratory scientist Zdeněk Sekanina, the latest impactor to actually make contact with the Sun was the "supercomet" Howard-Koomen-Michels on August 30, 1979.^[41] (See also sungrazer.)

On October 7, 2008, a meteroid labeled 2008 TC3 was tracked for 20 hours as it approached Earth and as it fell through the atmosphere and impacted in Sudan. This was the first time an object was detected before it reached the atmosphere and hundreds of pieces of the meteorite were recovered from the Nubian Desert.^[42]

On July 19, 2009, a new black spot about the size of Earth was discovered in Jupiter's southern hemisphere by an amateur astronomer. Thermal infrared analysis showed it was warm and spectroscopic methods detected ammonia. JPL scientists confirmed that another impact event on Jupiter had occurred, probably a small undiscovered comet or other icy body.^[43][44][45]

Hubble's Wide Field Camera 3 clearly shows the slow evolution of the debris coming from asteroid P/2010 A2, which is thought to be due to a collision with a smaller asteroid.

Between January and May 2010, Hubble's Wide Field Camera 3^[46] took images of an unusual X shape originated in the aftermath of the collision between asteroid P/2010 A2 with a smaller asteroid.

End of civilization[link]

An impact event is commonly seen as a scenario that would bring about the end of civilization. In 2000, Discover Magazine published a list of 20 possible sudden doomsday scenarios with impact event listed as the No. 1 most likely to occur.^[47] Until the 1980s this idea was not taken seriously, but opinions changed following the discovery of the Chicxulub Crater, which was further reinforced by witness to the Comet Shoemaker-Levy 9 event.^{[citation needed]}

Impact events in popular culture[link]

Social attitudes[link]

A joint Pew Research Center/Smithsonian survey from April 21–26, 2010 found that 31% of Americans believed that an asteroid will collide with Earth by 2050. A 61% majority disagreed.^[48]

Science fiction novels[link]

Numerous science fiction stories and novels center around an impact event; possibly the best-selling was the novel Lucifer's Hammer by Larry Niven and Jerry Pournelle. Arthur C. Clarke's novel Rendezvous with Rama opens with a significant asteroid impact in northern Italy in the year 2077 which gives rise to the Spaceguard Project, which later discovers the Rama spacecraft. In 1992 a Congressional study in the U.S. led to NASA being directed to undertake a Spaceguard Survey with the novel being named as the inspiration for the name to search for Earth-impacting asteroids.^[49] This in turn inspired Clarke's 1993 novel The Hammer of God. A variation on the traditional impact story was provided by Jack McDevitt's 1999 novel Moonfall, in which a very large comet traveling at interstellar velocities collides with and partially destroys the Moon, fragments of which then collide with the Earth. The 1985 Niven and Pournelle novel Footfall features the examination of the effects of planetary warfare conducted by an alien species that culminates in the use of asteroids to bombard the planet, creating very large craters and the human species' near extinction. Jules Verne contributed a story of planetary impact in "Off on a Comet". Robert A. Heinlein used the concept of guided meteors in two novels. In "The Moon is a Harsh Mistress", the moon rebels use rock filled shipping containers as a weapon against their Earthside oppressors and in "Starship Troopers" the Bugs use a meteor to destroy Buenos Aires.

Similarly in the science fiction television series Babylon 5 war between the Narn and Centauri is brought to a swift end when the Centauri use "Mass Drivers" a weapon system that propels asteroids at the surface of the Narn home world causing severe ecological damage.

The novelization based on, as well as the actual game Rage, is based on an alternate future, where the end of the world is caused by impact with 99942 Apophis.

Cinema[link]

Several disaster films have also been made: released during the turbulence of World War I, the Danish feature film The End of the World revolves around the near-miss of a comet which causes fire showers and social unrest in Europe.^[50] When Worlds Collide (1951) based on a 1933 novel by Philip Wylie, deals with two planets on a collision course with Earth – the smaller planet a "near miss," causing extensive damage and destruction, followed by a direct hit from the larger planet.^[51] Meteor (1979) features small asteroid fragments and a large 8 km (5 mi) wide asteroid heading for Earth. Orbiting U.S. and Soviet nuclear weapons platforms are turned away from their respective earthbound targets, and toward the incoming threat. In 1998, two films were released in the United States on the subject of attempting to stop impact events: Touchstone Pictures' Armageddon, about an asteroid; and Paramount/DreamWorks' Deep Impact, about a comet. Both involved using Space Shuttle-derived craft to deliver large amounts of nuclear weapons to destroy their targets. The 2008 American Broadcasting Company's miniseries Impact deals about a splinter of a brown dwarf hidden in a meteor shower which strikes the Moon and sends it on a collision course with Earth. The 2011 film Melancholia uses the motif of an impact event incorporated in the aesthetics of romanticism.^[52]

See also[link]

References[link]

Further reading[link]

• Alvarez, L. W.; Alvarez, W.; Asaro, F.; Michel, H. V. (1980), "Extraterrestrial Cause for the Cretaceous-Tertiary Extinction", Science 208 (4448): 1095–1108, Bibcode 1980Sci...208.1095A, DOI:10.1126/science.208.4448.1095, PMID 17783054 
• Benton, Michael J. (2003), When Life Nearly Died: The Greatest Mass Extinction of All Time, New York: Thames and Hudson, ISBN 0-500-05116-X 
• Blakeslee, Sandra (14 November 2006), "Ancient Crash, Epic Wave", New York Times, http://www.nytimes.com/2006/11/14/science/14WAVE.html 
• Shukolyukov, A.; Lugmair, G. W. (1998), "Isotopic Evidence for the Cretaceous-Tertiary Impactor and Its Type", Science 282 (5390): 927–929, Bibcode 1998Sci...282..927S, DOI:10.1126/science.282.5390.927, PMID 9794759 
• Smit, J.; Hertogen, J. (1980), "An extraterrestrial event at the Cretaceous-Tertiary boundary", Nature 285 (5762): 198–200, Bibcode 1980Natur.285..198S, DOI:10.1038/285198a0 
• Stone, R. (August 2008), "Target earth", National Geographic Magazine 

External links[link]

Wikimedia Commons has media related to: Impact events

• EARTH IMPACTS from Greg Goebel's IN THE PUBLIC DOMAIN
• Earth Impact Database
• Earth Impact Effects Program
• Nature journal video discussing historical impact event on Mars
• Impact Structure (Crater) Explorations
• All 172 confirmed meteor impact sites on earth, viewable in Google Earth (Largest, Most recent, Per continent, Including size indicator)
• Impact Meteor Crater Viewer Google Maps Page with Locations of Meteor Craters around the world
• Reorienting Western Society to Battle Impact Events Jagiellonian University, Poland
• A comet or asteroid impact with the earth - How real is the threat? Bob Hawkes
• arguing for a globally cooperative Earth Defense Initiative (EDI)
• Traces of Catastrophe
• GEOSIM - Information on impact processes and effects; 3-D-simulation
• Down 2 Earth Impact Calculator Interactive simulator showing size of craters on Google Maps
• Impact Site Map Interactive map, with simple html drilldowns to Google satellite maps of impact sites.
• Judson L. Ahern, Univ. of Okla.: DETECTING BURIED IMPACT STRUCTURES: EARTH AND MARS - general interest article
• Shoemaker Levy 9 Wow Signal impact sequenz
• Asteroid Impactor Reported over Indonesia
• R. Marcus, H. J. Melosh, and G. Collins. Earth Impact Effects Program, an online calculator for qualitative estimation of impact effects. Purdue University, Imperial College London.

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Hulk Hogan
Hulk Hogan at the MCI Center in Washington, D.C. (August 21, 2005)
Ring name(s)	The Super Destroyer[1] Hulk Hogan[1] Hollywood Hulk Hogan[1] Hollywood Hogan[2] Terry Boulder[1] Mr. America Sterling Golden
Billed height	6 ft 7 in (2.01 m)[3]
Billed weight	302 lb (137 kg)[1]
Born	(1953-08-11) August 11, 1953 (age 58)[1] Augusta, GA[1]
Resides	Tampa, Florida[1]
Billed from	Venice Beach, California[3] Washington, D.C. (as Mr. America)[4] Hollywood, California (as Hollywood Hogan)
Trained by	Hiro Matsuda[1]
Debut	August 10, 1977[1]
Website	hulkhogan.com

Terry Gene Bollea^[5] (born August 11, 1953),^[1] better known by his ring name Hulk Hogan, is an American professional wrestler, actor, television personality, and musician signed to Total Nonstop Action Wrestling (TNA).^[6]

Hogan enjoyed mainstream popularity in the mid 1980s through the early 1990s as the all-American character Hulk Hogan in the World Wrestling Federation (WWF—now WWE), and was notable in the mid-to-late 1990s as Hollywood Hogan, the villainous nWo leader, in World Championship Wrestling (WCW). Following the closure of WCW, he made a brief return to WWE in the early 2000s before revising his heroic character by combining elements of his two most famous personas.

Hogan was later inducted into the WWE Hall of Fame in 2005. He is a 12-time world champion being a six-time WWF/WWE Champion, six-time WCW World Heavyweight Champion, as well as a former WWE World Tag Team Champion with Edge. He won the Royal Rumble in 1990 and 1991, making him the first to win two consecutive Royal Rumbles. He was also the first WWE wrestler to win the WWE Championship three times. In his first reign as WCW World Heavyweight Champion, Hogan held the title for 469 days from July 17, 1994 to October 29, 1995—the longest ever reign for this championship.

Early life[link]

Hogan, born Terry Gene Bollea, was born in Augusta, Georgia, the son of Peter Bollea, a construction foreman, and Ruth, a homemaker and dance teacher. He is of Italian, French, and Panamanian heritage.^[7]

When he was one and a half years old, his family moved to Port Tampa, Florida.^[8]

As a boy, he was a pitcher in Little League Baseball. He began watching professional wrestling at 16 years old. While in high school, he revered Dusty Rhodes,^[9] and he regularly attended cards at the Tampa Sportatorium. It was at one of those wrestling cards where he first turned his attention towards "Superstar" Billy Graham and looked to him for inspiration;^[9] since he first saw Graham on TV,^[9] Hogan wanted to match his "inhuman" look.^[9] Hogan was also a skilled musician, spending ten years playing bass guitar in several Florida-based rock bands.^[2]

He went on to study at Hillsborough Community College and the University of South Florida. After music gigs began to get in the way of his time in college, Hogan decided to drop out of the University of South Florida before receiving any degree.^[10] Eventually, Hogan and two local musicians formed a band called Ruckus in 1976.^[11] The band soon became a local sensation in the Tampa Bay region.^[11]

During his spare time, Hogan would work out at Hector's Gym in the Tampa Bay area and eventually became strong enough to do big lifting.^[12] Many of the wrestlers who were competing in the Florida region visited the bars where Ruckus was performing.^[9] Among those attending his performances were Jack and Gerald Brisco,^[9] two brothers who wrestled together as a tag team in the Florida region. Impressed by Hogan's physical stature, the Brisco brothers asked Hiro Matsuda—the man who trained wrestlers working for Championship Wrestling from Florida (CWF)—to make him a potential trainee.^[13] In 1976, the two brothers asked Hogan to try wrestling. Having been a wrestling fan since childhood,^[9] Hogan eventually agreed.^[14] At first, however, Mike Graham, the son of CWF promoter Eddie Graham, refused to put Hogan in the ring;^[15] according to Hogan, he met Graham while in high school and the two didn't get along.^[15] However, after Hogan quit Ruckus and started telling people in town that he was going to be a wrestler,^[15] Mike Graham finally agreed to accept the Brisco Brothers' request.

Professional wrestling career[link]

Early years (1977–1979)[link]

In the summer of 1977, after over a year of training with Matsuda,^[16] the Brisco brothers dropped by Matsuda's gym to see Hogan.^[16] During this visit, Jack Brisco handed Hogan a pair of wrestling boots and informed him that he was scheduled to wrestle his first match the following week.^[16] In his professional wrestling debut, Eddie Graham booked him against Brian Blair in Fort Myers, Florida on August 10, 1977 in Championship Wrestling from Florida.^[17][18] A short time later, Bollea donned a mask and assumed the persona of "The Super Destroyer," a hooded character first played by Don Jardine and subsequently used by other wrestlers. Hogan, however, eventually could no longer work with Hiro Matsuda,^[19] whom he felt was an overbearing trainer,^[19] and left Championship Wrestling From Florida.^[20] After declining an offer to wrestle for the Kansas City circuit,^[20] Hogan took a hiatus from wrestling and managed a private club in Cocoa Beach, Florida-known as the Anchor Club-.^[20] for a man named Whitey Bridges.^[20] Eventually, Whitey and Hogan became close friends, and decided to open a gym together;^[20] the gym would be known as Whitey and Terry's Olympic gym.^[20] Soon after, Hogan's friend Ed Leslie (later known as Brutus Beefcake) came down to Cocoa Beach to help Hogan and Bridges manage both the Anchor Club and the Whitey and Terry's Olympic Gym.^[20] On his spare time, he and Beefcake would work out in the gym together,^[20] and eventually, Beefcake developed a muscular physique;^[21] Hogan was impressed by Beefcake's physical stature and became convinced that the two of them should wrestle together as tag team partners.^[21] Depressed and yearning to return to wrestling,^[21] Hogan called Superstar Billy Graham in 1978 with hopes that Graham could find him a job wrestling outside of Florida;^[21] Graham agreed and Hogan soon joined Louie Tillet's Alabama territory.^[21] Hogan also convinced Beefcake, who had yet to become a wrestler,^[21] to come with him and promised to teach him everything he knew about the sport.^[21]

In Alabama, he and Beefcake wrestled as Terry and Ed Boulder, known as the Boulder Brothers.^[22] These early matches as a tag team with the surname Boulder being used by both men prompted a rumor among wrestling fans unaware of the inner workings of the sport that Hogan and Beefcake were brothers,^[22] as few people actually knew their real names outside of immediate friends, family, and of course the various promoters the two worked for. After wrestling a show for Continental Wrestling Association (CWA) in Memphis,^[23] Jerry Jarrett, the promoter for the (CWA), approached Hogan and Beefcake and offered them a job in his promotion for $800.00 a week;^[23] this was far more than the $175.00 a week they would make working for Tillet.^[23] Hogan and Beefcake accepted this offer and left Tillet's territory.^[23]

During his time in Memphis, Hogan appeared on a local talk show, where he sat beside Lou Ferrigno, star of the television series The Incredible Hulk.^[24] The host commented on how Terry, who stood 6 ft 7 in (201 cm) and weighed 295 pounds with 24 inch biceps, actually dwarfed "The Hulk." Watching the show backstage, Jerry Jarrett noticed that Hogan was actually bigger than Ferrigno, who was well known at the time for having large muscles.^[25] As a result, Bollea began performing as Terry "The Hulk" Boulder^[25] and sometimes wrestled as Sterling Golden.^[2]

In May 1979, Bollea had an early shot at the NWA World Heavyweight Championship, which at the time was generally recognized as the highest honor in wrestling. In June 1979, Bollea won his first wrestling championship, the NWA Southeast Heavyweight Championship, recognized in Alabama and Tennessee when he defeated Ox Baker.

World Wrestling Federation (1979–1980)[link]

Later that year, former NWA World Champion Terry Funk introduced Bollea to the company head Vincent J. McMahon, who was impressed with his charisma and physical stature. McMahon, who wanted to use an Irish name, gave Bollea the last name Hogan, and also wanted him to dye his hair red. Hogan who said his hair was already beginning to fall out, refused to dye it and simply said "I'll be a blond irish.^[26] At this time, Hogan wrestled Bob Backlund for the World Championship,^[27] and he started his first big feud with André the Giant, which culminated in a match with André at Shea Stadium in August 1980.^[28] Hulk Hogan claims in his autobiography that he and André the Giant were the reason for the Shea gate. However, Sammartino/Zbyszko sold out everywhere they wrestled leading up the show. Hogan and Andre wrestled in White Plains, New York, drawing 1,200 in a building that held 3,500 as the main event before they wrestled at Shea. During his initial heel run in the WWF, Hogan was paired with "Classy" Freddie Blassie, a wrestler-turned-manager.

New Japan Pro Wrestling (1980–1985)[link]

A great deal of Hogan's early success was achieved in New Japan Pro Wrestling. Japanese wrestling fans were in awe of the gargantuan blond American and nicknamed him "Ichiban" (which translates to "Number One"). Hogan first appeared in Japan on May 13, 1980, while he was still with the WWF. He occasionally toured the country over the next few years, facing a wide variety of opponents ranging from Tatsumi Fujinami to Abdullah the Butcher. When competing in Japan, Hogan used a vastly different repertoire of wrestling moves, relying on more technical, traditional wrestling holds and maneuvers as opposed to the power-based, brawling style American fans became accustomed to seeing from him. Another difference is that Hogan used a running forearm lariat (called the "Axe Bomber") as his finisher in Japan instead of the running leg drop that has been his traditional finisher in America. On June 2, 1983, Hogan became the first International Wrestling Grand Prix (IWGP) tournament winner (although he held the IWGP Heavyweight Championship belt, this was not the beginning of the actual championship), defeating Japanese wrestling icon Antonio Inoki by knockout in the finals of a 10-man tournament featuring top talent from throughout the world.^[29] Hogan and Inoki also worked as partners in Japan, winning the prestigious MSG Tag League tournament two years in a row: in 1982 and 1983. Hogan's popularity in Japan was so great, he even recorded an album there—a forerunner to the World Wrestling Federation's "Rock 'n' Wrestling" of the mid 1980s.

In 1984, Hogan returned to New Japan, to wrestle Antonio Inoki in the finals of the IWGP League, in which he lost the belt by countout, thanks to interference from Riki Choshu. Hogan would also defend his WWF World title against various stars in New Japan including Inoki, Seiji Sakaguchi, and Tatsumi Fujinami among others, until the WWF ended their relationship with New Japan in October 1985.

American Wrestling Association (1981–1983)[link]

After filming his scene for Rocky III against the elder McMahon's wishes, Hogan made his debut in the American Wrestling Association, owned by Verne Gagne. Hogan started his AWA run as a heel, taking on "Luscious" Johnny Valiant as his manager, before handing the AWA title over to him. Hogan, unwilling to give up his life as a bachelor for the world title of the AWA, continued to turn down the belt. Shortly after these attempts to woo Hogan into giving Gagne more of a share of his profits and booking in Japan and attempts to bring him into the Gagne family, Hogan was lured back to the Northeast by Vincent K. McMahon, who had just recently purchased the WWF from his ailing father.

Over twenty years later, just prior to Hulk Hogan's WWE Hall of Fame induction in 2005, the revived American Wrestling Association, under the authority of owner Dale Gagner, retroactively acknowledged Hogan's two previously-overturned title wins over Nick Bockwinkel making Hogan a two-time AWA World Heavyweight Wrestling Champion.^[30] This resolution, however, has been regarded as apocryphal to most as the resurrected AWA is generally regarded as a different body than the Verne Gagne–owned AWA of old. As recently as the release of the DVD The Spectacular Legacy of the AWA, interviews between Hogan and the Gagnes show that there is still animosity between both parties indicating the unlikelihood that Hogan's AWA title reign would have been retroactively instated under the original ownership. The WWE won a lawsuit against Dale Gagner, due to trademark infringement, which declared Gagner's claims to ownership of the AWA false and as such rendered the resolution moot as WWE only recognizes twelve American world championships being attributed to Hulk Hogan, and, the AWA World Championship is not among that number.^{[citation needed]}

Return to World Wrestling Federation (1983-1993)[link]

The Birth of Hulkamania (1983–1984)[link]

Hogan as the Heavyweight Champion with Brutus Beefcake.

After purchasing the company from his father in 1982, Vincent K. McMahon had plans to expand the territory into a nationwide promotion, and he handpicked Hulk Hogan to be the company's showpiece attraction due to his charisma and name recognition. Hogan made his return at a television taping in St. Louis, Missouri on December 27, 1983 defeating Bill Dixon.^[31]

On the January 7, 1984 edition of Championship Wrestling, Hogan confirmed his face status for the WWF fans by saving Bob Backlund from a three-way assault.^[32] Hogan's turn was explained simply by Backlund: "He's changed his ways. He's a great man. He's told me he's not gonna have Blassie around." The storyline shortcut was necessary because less than three weeks later on January 23, Hogan won his first WWF Championship, pinning The Iron Sheik (who had Blassie in his corner) in Madison Square Garden.^[2][33] The storyline accompanying the victory was that Hogan was a "last minute" replacement for the Sheik's original opponent Bob Backlund,^[3] and became the champion by way of being the first man to escape the camel clutch (the Iron Sheik's finishing move).^[34] The backstage story was that the WWF Champion Bob Backlund had refused to let Hogan win the title from him, demanding that any wrestler to whom he lost the belt have a legitimate wrestling background. As a consequence, The Iron Sheik won the title from Backlund first and then dropped it to Hogan.

Immediately after the title win, commentator Gorilla Monsoon proclaimed "Hulkamania is here!" Hogan frequently referred to his fans as "Hulkamaniacs" in his interviews and introduced his three "demandments": training, saying prayers, and eating vitamins. Eventually, a fourth demandment (believing in oneself) was added during his feud with Earthquake in 1990. Hogan's ring gear developed a characteristic yellow-and-red color scheme; his ring entrances involved him ritualistically ripping his shirt off his body, flexing, and listening for audience cheers in an exaggerated manner. The majority of Hogan's matches during this time involved him wrestling heels who had been booked as unstoppable monsters, using a format which became near-routine: Hogan would deliver steady offense, but eventually lose momentum, seemingly nearing defeat. He would then experience a sudden second wind, fighting back while "feeding" off the energy of the audience, becoming impervious to attack—a process described as "Hulking up". His signature maneuvers—pointing at the opponent (which would later be accompanied by a loud "YOU!" from the audience), shaking his finger to scold him, three punches, an Irish Whip, the big boot and running leg drop—would follow and ensure him a victory. That finishing sequence would occasionally change depending on the storyline and opponent; for instance, with "Giant" wrestlers, the sequence might involve a body slam.

Over the next year, Hulk Hogan became the face of pro wrestling as McMahon pushed the WWF into a pop culture enterprise with The Rock 'n' Wrestling Connection on MTV, drawing record houses, pay-per-view buyrates, and television ratings in the process. The centerpiece attraction for the first WrestleMania on March 31, 1985, Hogan teamed with legit friend Mr. T to defeat his archrival "Rowdy" Roddy Piper and Paul Orndorff.^[2][35] On the first edition of Saturday Night's Main Event, Hogan successfully defended the WWF title against Cowboy Bob Orton in a match which Hogan won by a disqualification.^[36]

Hogan was named the most requested celebrity of the 1980s for the Make-a-Wish Foundation children's charity. He was featured on the covers of Sports Illustrated, TV Guide, and People magazines, while also appearing on The Tonight Show and having his own CBS Saturday morning cartoon titled Hulk Hogan's Rock 'n' Wrestling. Hogan, as the premier WWF icon, headlined eight of the first nine WrestleMania events. He also co-hosted Saturday Night Live on March 30, 1985 during this lucrative run. AT&T reported that his 900 number information line was the single biggest 900 number from 1991 to 1993. Hogan operated the 900 number through his stint in WWF and then recreated it when he joined World Championship Wrestling.^[37]

WWF Champion (1984–1988)[link]

On the October 5, 1985 edition of Saturday Night's Main Event, he successfully defended the title against Nikolai Volkoff in a flag match.^[38] He met long-time rival Roddy Piper in a WWF title match at the Wrestling Classic pay-per-view (PPV) event. Hogan retained the title by disqualification after Bob Orton interfered and hit Hogan with his cast.^[39] Hogan had many challengers in the way as the new year began. Throughout 1986, Hogan made successful title defenses against challengers such as Terry Funk,^[40] "The Magnificent" Don Muraco,^[41] King Kong Bundy (in a steel cage match at WrestleMania 2),^[42] Paul Orndorff,^[43] and Hercules Hernandez.^[44]

In the fall of 1986, Hogan occasionally wrestled in tag matches with The Machines as Hulk Machine under a mask copied from New Japan Pro Wrestling gimmick "Super Strong Machine."^[1][45] At WrestleMania III in 1987, Hogan was booked to defend the title against André the Giant, who had been the sport's premier star and was pushed as undefeated for the previous two decades. A new storyline was introduced in early 1987; Hogan was presented a trophy for being the WWF Champion for three consecutive years.^[46] André the Giant, a good friend came out to congratulate him.^[47] Shortly afterward, André was presented a slightly smaller trophy for being "undefeated in the WWF for 15 years."^[46] Hogan came out to congratulate André, who walked out in the midst of Hogan's speech. Then, on an edition of Piper's Pit, Hogan was confronted by Bobby Heenan, who announced that André was his new protégé, and Andre challenged Hogan to a title match at WrestleMania III.^{[47][48][49][50]} At WrestleMania III, Hogan successfully defended the WWF World Heavyweight Championship against André the Giant. During the match, Hogan bodyslammed the 520-pound Frenchman (which was dubbed "the bodyslam heard around the world") and won the match after a leg drop.^[48][51]

Hogan remained WWF Champion for four years (1,474 days).^[52] In front of 33 million viewers, however, Hogan finally lost the belt to André on the February 5 edition of The Main Event after a convoluted scam involving "The Million Dollar Man" Ted DiBiase and Earl Hebner (who assumed the place of his twin brother Dave Hebner, the match's appointed referee).^[53] After André delivered a belly to belly suplex on Hogan, Hebner counted the pin while Hogan's left shoulder was clearly off the mat.^[3] After the match, André handed the title over to DiBiase to complete their business deal.^[53] As a result, the WWF Championship was vacated for the first time in its 25-year history.^[53] At WrestleMania IV, Hogan participated in a tournament for the vacant WWF title to regain it and faced André in the tournament quarter-finals but their match resulted in a double disqualification.^[54] Later that night in the main event, Hogan interfered and helped "Macho Man" Randy Savage defeat Ted DiBiase to win the title.^[55]

The Mega Powers (1988–1989)[link]

Together, Hogan, Savage, and manager Miss Elizabeth formed a partnership known as The Mega Powers.^[56] After Savage became WWF Champion at WrestleMania IV, they feuded with The Mega Bucks (Ted DiBiase and André the Giant) and defeated them at the main event of the first SummerSlam.^[57] The Mega Powers, however, soon imploded from within in 1989, due to Savage's burgeoning jealousy of Hogan and his paranoid suspicions that Hogan and Elizabeth were "more than friends". Dissension was furthered at the Royal Rumble, when Hogan eliminated Savage from the Royal Rumble match.^[58] The duo broke up while wrestling The Twin Towers on the February 3, 1989 edition of The Main Event. During the match, Savage accidentally collided with Miss Elizabeth. Hogan took her backstage to receive medical attention, while temporarily abandoning Savage. When he returned to the ring, Savage slapped Hogan and left the ring, where Hogan eventually won the match by himself.^[59] After the match, Savage attacked Hogan backstage, which started a feud between the two.^[56] Their feud culminated in Hogan beating Savage for his second WWF Championship at WrestleMania V.^[3][56]

Later WWF Championship reigns (1989–1992)[link]

Hogan making his way to the ring in 1989.

Hogan's second run lasted a year, during which time he starred in the movie No Holds Barred. The film was the inspiration of a feud with Hogan's co-star Tom Lister, Jr., who appeared at wrestling events as his movie character, Zeus. Zeus was a monster heel who was "jealous" over Hogan's higher billing and wanted revenge. Hogan, however, was easily able to defeat Zeus in a series of matches across the country during late 1989, beginning with a tag team match at SummerSlam, in which Hogan and Brutus Beefcake topped Zeus and Savage.^[60] Hogan and Beefcake defeated Zeus and Savage in a rematch at the No Holds Barred pay-per-view to end the feud.^[61][62]

Hogan's second title run was briefly interrupted in January 1989 when he was defeated via submission by Dino Bravo after Hogan couldn't break Bravo's bearhug hold. Hogan attempted to "Hulk Up" and turn the match around, but Bravo wouldn't release the hold, and Hogan became unconscious, forcing the ref to call the match. A silenced crowd watched Bravo grab the championship belt no sooner than an announcement was made that Hogan was determined the winner, by way of disqualification, therefore retaining his title and championship. An infuriated Bravo was quoted, "Last I checked, a bearhug was a legal move. The better and stronger wrestler just got cheated." The Wrestler magazine covered the story in their February 1989 issue with Bravo's hold on Hogan on the front cover with the title, "The Man That Hulk Hogan Cannot Beat." Also during his second run, Hogan won the 1990 Royal Rumble match.^[3][63] He dropped the title to Intercontinental Champion The Ultimate Warrior in a title versus title match at WrestleMania VI on April 1, 1990.^[64]

Hogan soon became embroiled in a heated feud with the 470-pound Earthquake, who had crushed Hogan's ribs in a sneak attack on The Brother Love Show in May 1990. On television, announcers explained that Hogan's injuries and his WrestleMania VI loss to Warrior both took such a huge toll on his fighting spirit that he wanted to retire. Viewers were asked to write letters to Hogan and send postcards asking for his return (they got a postcard-sized picture in return, autographed by Hogan, as a "thank-you"). Hogan returned by SummerSlam 1990 and for several months, dominated Earthquake in a series of matches across the country.^[65] His defeat of this overwhelmingly large foe caused Hogan to add a fourth demandment: believing in yourself. He would also be known as "The Immortal" Hulk Hogan. Hogan then became the first wrestler to win two Royal Rumble matches in a row,^[66] as he won the 1991 Royal Rumble match.^[3][63][66]

At WrestleMania VII, Hogan stood up for the USA against Sgt. Slaughter, defeating him for his third WWF Championship.^[67] In the fall of 1991, Hogan was challenged by Ric Flair, the former NWA champion who recently arrived in the WWF. The feud remained unresolved, as Hogan lost the WWF title to The Undertaker at Survivor Series,^[68] and he won it back at This Tuesday in Texas six days later.^[69] Flair had interfered in both matches and due to the resulting controversy, the title was again declared vacant.^[69]

The WWF Championship was decided at the 1992 Royal Rumble in the Royal Rumble match. Hogan failed to regain the championship as he was eliminated by friend Sid Justice and in turn caused Sid to be eliminated, leaving Ric Flair the winner and new champion.^[70] Hogan and Sid patched things up and teamed together on the February 8, 1992 edition of Saturday Night's Main Event against Flair and Undertaker but during the match Sid abandoned Hogan,^[71] starting their feud. At WrestleMania VIII, Hogan defeated Sid via disqualification due to interference by Sid's manager Harvey Wippleman.^[72] Hogan was then attacked by Papa Shango and was saved by the returning Ultimate Warrior.^[72]

At this time, news sources began to allege that Dr. George Zahorian, a doctor for the Pennsylvania State Athletic Commission, had been selling steroids illegally to wrestlers in general and Hogan in particular. Hogan appeared on an episode of The Arsenio Hall Show to deny the allegations. Due to intense public scrutiny, Hogan took a leave of absence from the company.^[73]

Return and departure (1993–1994)[link]

Hogan returned to the WWF in February 1993, helping out his friend Brutus Beefcake in his feud with Money Inc. (Ted DiBiase and Irwin R. Schyster), and officially renaming themselves The Mega-Maniacs.^[61] At WrestleMania IX, Hogan and Beefcake took on Money Inc. for the WWF Tag Team Championship. However, Hogan thought he was too big of a star to be a tag champion and instead wanted the world title. So Hogan and Vince McMahon came up with the plan that Hogan and Brutus would be disqualified in their match.^[61][74] Later that night, Hogan won his fifth WWF Championship by pinning Yokozuna only moments after Yokozuna had defeated Bret Hart.^[74][75] McMahon then planned that Hogan and Bret Hart would eventually fight in a big match at Summerslam 1993 in which Hogan would drop the title to Hart, Hogan didn't want to drop the title in a clean victory to Hart, due to Hart's size and doubts over whether he could draw, and opted to lose the title to the heel Yokozuna instead. At the first annual King of the Ring pay-per-view on June 13, 1993, Hogan defended the championship against the former champion, Yokozuna, in his first title defense since defeating Yokozuna at WrestleMania IX. Yokozuna kicked out of Hogan's signature leg drop and scored the pinfall after Hogan was blinded by a fireball shot by a "Japanese photographer" (actually a disguised Harvey Wippleman), this was Hogan's idea as he did not want Yokozuna to gain a clean victory over him. The victorious Yokozuna proceeded to give Hogan a Banzai Drop.^[58][76] This would be Hogan's last WWF pay-per-view appearance until 2002, as both he and Jimmy Hart were preparing to leave the promotion. Hogan would continue his feud on the international house show circuit with Yokozuna until August 1993. After that, Hogan would sit out the rest of his contract which expired later that year.

In 1994, Hogan, having received immunity from prosecution, testified in the trial of Vince McMahon relating to shipments of steroids received from Dr. Zahorian by both parties. Under oath, Hogan admitted that he had used anabolic steroids since 1976 to gain size and weight, but that Vince McMahon had neither sold him the drugs, nor ordered him to take them. The evidence given by Hogan proved extremely costly to the government's case against McMahon. Due to this and jurisdictional issues, McMahon was found not guilty.^[77]

Return to New Japan (1993–1994)[link]

On May 3, 1993, Hulk Hogan returned to NJPW as WWF Champion, defeating IWGP Heavyweight Champion The Great Muta in a dream match at Wrestling Dontaku. Hogan would wrestle against Muta again, under his real name, Keiji Mutoh on September 26, 1993. Hogan would also wrestle The Hell Raisers with Muta and Masahiro Chono as his partners. His last match in Japan was on January 4, 1994 at Battlefield, when he defeated Tatsumi Fujinami.

World Championship Wrestling (1994-2000)[link]

Early run (1994–1996)[link]

After Hogan left the WWF in the summer of 1993, he split his time working on movies, television, wrestling in Japan, and spending time with his family. In June 1994, Hogan signed with Ted Turner's World Championship Wrestling (WCW) and began appearing on television the next month. Hogan won the WCW World Heavyweight Championship in his debut match, defeating Ric Flair in a 'dream' match at Bash at the Beach.^[78] After overcoming the likes of Flair,^[79] The Butcher (former partner Brutus Beefcake),^[80] Vader,^[81][82][83] and the Dungeon of Doom^[84] for the next fifteen months (the longest reign of all time for this championship), Hogan dropped the belt to The Giant at Halloween Havoc 1995 via DQ.^[85] Following the controversial loss (which was due to a "contract clause"), the WCW title became vacant.

In early 1996, Hogan continued his feud with The Giant,^[86] before teaming with Randy Savage in a feud with the Alliance to End Hulkamania.^[87] After coming out victorious from his feuds, Hogan began to only appear occasionally on WCW programming.

New World Order (1996–1998)[link]

At Bash at the Beach in 1996, during a six man tag team match pitting The Outsiders (Kevin Nash and Scott Hall) against WCW loyalists, Hogan interfered on behalf of Nash and Hall, attacking Randy Savage, thereby turning heel for the first time in over ten years.^[1][58][88] After the match, Hogan delivered a promo, accosting the fans and WCW for underappreciating his talent and drawing power, and announcing the formation of the New World Order (nWo).^[88] The new stable gained prominence in the following weeks and months.^{[2][3][88][89]} Hogan grew a beard alongside his famous mustache and dyed it black, traded his red and yellow garb in for black and white clothing, often detailed with lightning bolts, and renamed himself Hollywood Hulk Hogan (often shortened to Hollywood Hogan). Hogan returned to WCW programming eight days after his heel turn.^[1][58]

Hogan won his second WCW World Heavyweight Championship at Hog Wild, defeating The Giant for the title.^[89][90] He spray painted "nWo" across the title belt, scribbled across the nameplate, and referred to the title as the "nWo title" during this and any other time he held the title while in the nWo.^[90] Hogan then started a feud with Lex Luger after Luger and The Giant defeated Hogan and Dennis Rodman in a tag team match at Bash at the Beach.^[85]

On the August 4, 1997 edition of Nitro, Hogan lost the WCW title to Luger by submission.^[91] Five days later, at Road Wild, Hogan defeated Luger to regain the WCW title and begin his third WCW World Heavyweight Championship.^[92] Hogan then lost the belt to Sting in a match at Starrcade. In the match, WCW's newly-contracted Bret Hart accused referee Nick Patrick of fast-counting a victory for Hogan and had the match restarted—with himself as referee.^[58] Sting later won by submission.^[58] After a rematch the following night, where Sting controversially retained the title, the WCW Championship became vacant.^[1] Sting then went on to win the vacant title against Hogan at SuperBrawl VIII.^[93]

Hogan then developed a rivalry with former friend (and recent nWo recruit) Randy Savage, who had just cost Hogan the title match at SuperBrawl by hitting him with a spray can.^[58] The heat culminated in a steel cage match at Uncensored, which ended in a no contest.^[94] Savage took the World Championship from Sting at Spring Stampede, while Hogan teamed with Kevin Nash to take on Roddy Piper and The Giant in the first-ever Bat match.^[95] Hogan betrayed Nash by hitting him with the bat and then challenged Savage the following night for his championship.^[89] In the no disqualification match for Savage's newly won title, Nash entered the ring and powerbombed Hogan as retribution for the attack the previous night. Bret Hart interfered moments later and turned heel by jumping in to attack Savage and preserve the victory for Hogan, who won his fourth WCW World Heavyweight Championship.^[96] However, Nash's attack on him signified a split of the nWo into two separate factions- Hogan's became nWo Hollywood and Nash's became nWo Wolfpac- that would feud with each other for the remainder of the year.

Hogan defended the title until July of that year, when WCW booked him in a match against newcomer and then WCW United States Champion Bill Goldberg, who had yet to lose a match in the company. Late in the match, Hogan was distracted by Karl Malone, and Goldberg pinned Hogan to win the WCW World Heavyweight Championship.^[97]

Hogan spent the rest of 1998 wrestling celebrity matches. His second tag team match with Dennis Rodman pitted them against Diamond Dallas Page and Karl Malone at Bash at the Beach^[98] and at Road Wild, he and Eric Bischoff lost to Page and Jay Leno thanks to interference from Kevin Eubanks, who leveled Bischoff with a Diamond Cutter.^[99] Hogan also had a rematch with the Ultimate Warrior at Halloween Havoc, where his nephew Horace aided his victory.^[100]

Return to WCW (1998-1999)[link]

On the Thanksgiving episode of The Tonight Show with Jay Leno, Hogan officially announced his retirement from professional wrestling, as well as his candidacy for President of the United States.^[101] Campaign footage aired on Nitro of Hogan and Bischoff holding a press conference, making it appear legitimate. In the long run, however, both announcements were false and merely done as a publicity stunt attempting to draw some of the hype of Jesse Ventura's Minnesota gubernatorial win back to him.^[101]

After some time off from WCW, Hogan returned on the January 4, 1999 edition of Nitro to challenge Kevin Nash for the WCW title. Hogan won the match for his fifth WCW World Heavyweight Championship, but many people found the change to be "scandalous".^[102] As a result, the warring factions of the nWo reunited into one group, which began feuding with Bill Goldberg and The Four Horsemen.

Conflicts with Vince Russo (1999–2000)[link]

He then lost the title to Ric Flair at Uncensored in a Steel Cage First Blood match. A heavily bleeding Flair won via pinfall in a match refereed by Charles Robinson.^[1][103] During that match, however, Hogan began to show some signs that a face turn was imminent, showing off some old tactics like his "Hulking up" no-sell.^[58] The turn would have to wait, however, as Hogan was severely injured in a Texas Tornado match for the world championship featuring him, Sting, Diamond Dallas Page, and Flair at Spring Stampede^[104]

On the July 12 edition of Nitro, Hogan made his grand return as a full-fledged face and accepted a challenge from Savage, who had gained the world title at Bash at the Beach the night before in a tag team match by pinning Kevin Nash. Thanks to interference from Nash, Hogan defeated Savage to win his sixth and final WCW World Heavyweight Championship.^[105] Nash turned on him the next week, however, and the two began a feud that would last until the next pay-per-view.

On August 9, 1999, he started the night dressed in the typical black and white, but after a backstage scene with his son, Hogan came out dressed in the traditional red and yellow for his main-event 6-man tag team match. He then defeated Nash in a retirement match at Road Wild to retain his title. Injuries and frustrations were mounting up however, and he was absent from television from October 1999 to February 2000. In his book Hollywood Hulk Hogan, Bollea said that he was asked to take time off by newly hired head of creative booking Vince Russo and was not told when he would be brought back at the time. Despite some reservations, he agreed to do so. On October 24 at Halloween Havoc, Hogan was to face Sting for the WCW World Heavyweight Championship (which he had lost to Sting at Fall Brawl the previous month, when Sting beat Hogan by cheating and had turned heel in the process).^[106] Hogan, however, came to the ring in street clothes, laid down for the pin, and left the ring.^[107]

Hogan in 2000

Soon after his return in February 2000, at Bash at the Beach on July 9, Hogan was involved in a controversial, legit incident with Vince Russo. Hogan was scheduled to wrestle Jeff Jarrett for the WCW World Heavyweight Championship.^[108] Before the match, there was a dispute between Hogan and Russo. Unbeknownst to Hogan, Russo told Jarrett to lie down in the middle of the ring and asked Hogan to pin him straight away. A visibly confused Hogan complied with a foot on Jarrett's chest after getting on the microphone and telling Russo, "Is this your idea, Russo...? That's why this company is in the damn shape it's in, because of bullshit like this!" Russo responded by coming out and angrily proclaiming "I can guarantee you that this is the last time you will ever see that piece of shit in a WCW stadium!" This is also when the public discovered, through Russo, the "creative control" clause that Hogan had, which meant that Hogan was able to control what would happen with his own character and be able to do so without anyone else being able to tell him no. This has been a common complaint about Hogan, since he has been known to request such clauses in his contracts (even in WWE) because it is believed by many that he uses them to be able to "bury" others that would prove to be a threat to his legacy (which also might lead to the belief that the on-air criticisms that Bobby Heenan and then later Mark Madden made about him were not kayfabe even though the two usually were heel commentators, with Madden saying "Amen!" when Russo said that Hogan would not be back in WCW after that night). In his Bash at the Beach shoot promo, Russo said that he was arguing with Hogan all day prior to the event in the back because he wanted to use the clause in the Jarrett match, saying, "That means that, in the middle of this ring, when [Hogan] knew it was bullshit, he beats Jeff Jarrett!"

Since Hogan refused to job to Jarrett, a new WCW World Heavyweight Championship was created, setting the stage for a title match between Booker T and Jeff Jarrett later that night.^[58] Whether or not the whole incident was a shoot or a work was hotly debated. As a result, Hogan filed a defamation of character lawsuit against Russo soon after,^[109] which was eventually dismissed in 2002. Russo claims the whole thing was a work, and Hogan claims that Russo made it a shoot.^[110] Eric Bischoff agreed with Hogan's side of the story when he wrote that Hogan winning and leaving with the title was a work, and that he and Hogan celebrated after the event over the success of the angle, but that Russo coming out to fire Hogan was an unplanned shoot which led to the lawsuit filed by Hogan.^[1][109]

In the months following the eventual demise of WCW in March 2001, Hogan underwent surgery on his knees in order for him to wrestle again. As a test, Hogan worked a match in Orlando, Florida for the Xcitement Wrestling Federation promotion run by his longtime handler Jimmy Hart. Hogan defeated Curt Hennig in this match and felt healthy enough to accept an offer to return to the WWF in February 2002.^[1]

Return to World Wrestling Federation/Entertainment[link]

Hollywood Hogan and Undisputed WWF Champion (2002)[link]

At No Way Out in 2002, Hogan returned to the company that had made him a pop culture icon.^[3] Returning as leader of the original nWo with Scott Hall and Kevin Nash, the three got into a confrontation with The Rock^[111] and cost Stone Cold Steve Austin a chance at becoming the Undisputed WWF Champion against Chris Jericho in the main event.^[111] The nWo feuded with both Austin and The Rock, and Hogan accepted The Rock's challenge to a match at WrestleMania X8. At the event, Hogan asked Hall and Nash not to interfere, wanting to defeat The Rock by himself. Despite the fact that Hogan was supposed to be the heel in the match, the crowd cheered for him heavily. The Rock cleanly won the contest,^[112] but befriended Hogan at the end of the bout and helped him fight off Hall and Nash, who were upset by Hogan's conciliatory attitude.^[113] After the match, Hogan was a definite face again, siding with The Rock, though he continued wearing black and white tights for a few weeks after WrestleMania X8 until he resumed wearing his signature red and yellow tights. During this period, the "Hulk Rules" logo of the 1980s was redone with the text "Hulk Still Rules." Hulk wore the original "Hulk Rules" attire 12 years earlier, when he headlined WrestleMania VI at the same arena, in the SkyDome. For a time, he was still known as "Hollywood" Hulk Hogan, notably keeping the Hollywood Hogan style blond mustache with black beard while wearing Hulkamania-like red and yellow tights and using the Voodoo Child theme music he used in WCW. On April 4, Hogan feuded with Triple H and defeated him for the Undisputed WWF Championship and sixth and final WWF Championship at Backlash,^[114][115] thus becoming the last ever WWF champion before the initials dispute against the World Wildlife Fund For Nature. On May 19 at Judgment Day, he lost the belt to The Undertaker.^[116] After losing a Number One Contenders match for the Undisputed Championship to Triple H on June 6, Hogan began feuding with Kurt Angle resulting in a match between the two at the King of the Ring, which Angle won by submission.

On the July 4, 2002 edition of SmackDown!, Hogan teamed with Edge to defeat Billy and Chuck and capture the WWE World Tag Team Championship for the first time.^[117] They celebrated by waving the American flag as the overjoyed audience sang along to Hogan's theme song "Real American." They later dropped the titles to The Un-Americans (Lance Storm and Christian), at Vengeance.^[118] In August 2002, Hogan was used in an angle with Brock Lesnar, culminating in a main event singles match. Lesnar won by submission (the match was called after Hogan became unconscious from a bear hug hold). Lesnar became only the second WWE Superstar to defeat Hogan by submission (after Kurt Angle), and the first to defeat Hogan by having the match called. Following the match, Lesnar continued to beat on Hogan, leaving him bloody and unconscious in the ring in what many fans recall as the worst beating Hogan ever received of his career. As a result of Lesnar's assault, Hogan went on hiatus and was not able to return until early 2003, shaving off his black beard and dropping "Hollywood" from his name in his return. He battled The Rock (who had turned heel) once again at No Way Out^[119] and defeated Vince McMahon at WrestleMania XIX in a match billed as "20 years in the making."^[120]