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92-438: These rockets have been made at least since the early decades of the 20th century, and in many countries, including Japan and China. The older type of bottle rocket was typically a black powder skyrocket with an engine about 2 inches (5 cm) long and up to 0.375-inch (9-mm) diameter, mounted on a thin bamboo splint and often having a small report charge. Modern bottle rockets are small and very cheap. They are often sold by

184-443: A shaped charge the explosive forces are focused to produce a greater local explosion; shaped charges are often used by military to breach doors or walls. The speed of the reaction is what distinguishes an explosive reaction from an ordinary combustion reaction. Unless the reaction occurs very rapidly, the thermally expanding gases will be moderately dissipated in the medium, with no large differential in pressure and no explosion. As

276-403: A magnetic explosion . Strictly a physical process, as opposed to chemical or nuclear, e.g., the bursting of a sealed or partially sealed container under internal pressure is often referred to as an explosion. Examples include an overheated boiler or a simple tin can of beans tossed into a fire. Boiling liquid expanding vapor explosions are one type of mechanical explosion that can occur when

368-493: A Nemesis-style periodicity. 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 an impact event listed as the most likely to occur. A joint Pew Research Center / Smithsonian survey from April 21 to 26, 2010 found that 31 percent of Americans believed that an asteroid will collide with Earth by 2050. A majority (61 percent) disagreed. In

460-514: A diameter of 20 m (66 ft), and which strike Earth approximately twice every century, produce more powerful airbursts. The 2013 Chelyabinsk meteor was estimated to be about 20 m in diameter with an airburst of around 500 kilotons, an explosion 30 times the Hiroshima bomb impact. Much larger objects may impact the solid earth and create a crater. Objects with a diameter less than 1 m (3.3 ft) are called meteoroids and seldom make it to

552-444: A diameter of 4 meters (13 ft) enter Earth's atmosphere about once a year. Asteroids with a diameter of 7 meters enter the atmosphere about every 5 years with as much kinetic energy as the atomic bomb dropped on Hiroshima (approximately 16 kilotons of TNT), but the air burst is reduced to just 5 kilotons. These ordinarily explode in the upper atmosphere and most or all of the solids are vaporized . However, asteroids with

644-613: A group of iron meteorites were found, estimated as dating to 4,000–5,000 years ago. It first came to attention of Spanish authorities in 1576; in 2015, police arrested four alleged smugglers trying to steal more than a ton of protected meteorites. The Henbury craters in Australia (~5,000 years old) and Kaali craters in Estonia (~2,700 years old) were apparently produced by objects that broke up before impact. Whitecourt crater in Alberta, Canada

736-569: A hypothetical companion star to the Sun called Nemesis periodically disrupting the orbits of comets in the Oort cloud , leading to a large increase in the number of comets reaching the inner Solar System where they might hit Earth. Physicist Adrian Melott and paleontologist Richard Bambach have more recently verified the Raup and Sepkoski finding, but argue that it is not consistent with the characteristics expected of

828-556: A massive terrestrial planet impact was detected around the star ID8 in the star cluster NGC 2547 by NASA's Spitzer Space Telescope and confirmed by ground observations. Impact events have been a plot and background element in science fiction . In April 2018, the B612 Foundation reported: "It's 100 percent certain we'll be hit [by a devastating asteroid], but we're not 100 percent certain when." Also in 2018, physicist Stephen Hawking considered in his final book Brief Answers to

920-679: A merger signal of about 100 ms duration, during which time is it estimated to have radiated away nine solar masses in the form of gravitational energy. The most common artificial explosives are chemical explosives, usually involving a rapid and violent oxidation reaction that produces large amounts of hot gas. Gunpowder was the first explosive to be invented and put to use. Other notable early developments in chemical explosive technology were Frederick Augustus Abel 's development of nitrocellulose in 1865 and Alfred Nobel 's invention of dynamite in 1866. Chemical explosions (both intentional and accidental) are often initiated by an electric spark or flame in

1012-565: A mission to intercept an asteroid could be launched. On 26 September 2022, the Double Asteroid Redirection Test demonstrated the deflection of an asteroid. It was the first such experiment to be carried out by humankind and was considered to be highly successful. The orbital period of the target body was changed by 32 minutes. The criterion for success was a change of more than 73 seconds. Major impact events have significantly shaped Earth's history , having been implicated in

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1104-401: A result, even a nuclear weapon with a small yield is significantly more powerful than the largest conventional explosives available, with a single weapon capable of completely destroying an entire city. Explosive force is released in a direction perpendicular to the surface of the explosive. If a grenade is in mid air during the explosion, the direction of the blast will be 360°. In contrast, in

1196-447: A slower combustion process known as deflagration . For an explosion to occur, there must be a rapid, forceful expansion of matter. There are numerous ways this can happen, both naturally and artificially, such as volcanic eruptions , or two objects striking each other at very high speeds, as in an impact event . Explosive volcanic eruptions occur when magma rises from below, it has dissolved gas in it. The reduction of pressure as

1288-543: A slower expansion that would normally not be forceful, but is not allowed to expand, so that when whatever is containing the expansion is broken by the pressure that builds as the matter inside tries to expand, the matter expands forcefully. An example of this is a volcanic eruption created by the expansion of magma in a magma chamber as it rises to the surface. Supersonic explosions created by high explosives are known as detonations and travel through shock waves . Subsonic explosions are created by low explosives through

1380-537: A small portion of the mass of the explosive material. A material in which the first three factors exist cannot be accepted as an explosive unless the reaction can be made to occur when needed. Fragmentation is the accumulation and projection of particles as the result of a high explosives detonation. Fragments could originate from: parts of a structure (such as glass , bits of structural material , or roofing material), revealed strata and/or various surface-level geologic features (such as loose rocks , soil , or sand ),

1472-407: A vessel containing a pressurized liquid is ruptured, causing a rapid increase in volume as the liquid evaporates. Note that the contents of the container may cause a subsequent chemical explosion, the effects of which can be dramatically more serious, such as a propane tank in the midst of a fire. In such a case, to the effects of the mechanical explosion when the tank fails are added the effects from

1564-476: A volcanic origin, which has also been proposed as a cause for the iridium enrichment. Further, 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 a comet is also possible because comets are assumed to consist of material similar to carbonaceous chondrites. Probably

1656-641: A wood fire burns in a fireplace, for example, there certainly is the evolution of heat and the formation of gases, but neither is liberated rapidly enough to build up a sudden substantial pressure differential and then cause an explosion. This can be likened to the difference between the energy discharge of a battery , which is slow, and that of a flash capacitor like that in a camera flash, which releases its energy all at once. The generation of heat in large quantities accompanies most explosive chemical reactions. The exceptions are called entropic explosives and include organic peroxides such as acetone peroxide . It

1748-506: 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. Although no human is known to have been killed directly by an impact , over 1000 people were injured by

1840-422: Is absorbed during the formation of the compound from its elements; such a reaction is called an endothermic reaction. In explosive technology only materials that are exothermic —that have a net liberation of heat and have a negative heat of formation—are of interest. Reaction heat is measured under conditions either of constant pressure or constant volume. It is this heat of reaction that may be properly expressed as

1932-610: Is also coincidental to some of the earliest evidence of life on Earth, fossilized Stromatolites . Evidence for at least 4 impact events have been found in spherule layers (dubbed S1 through S8) from the Barberton Greenstone Belt in South Africa, spanning around 3.5-3.2 billion years ago. The sites of the impacts are thought to have been distant from the location of the belt. The impactors that generated these events are thought to have been much larger than those that created

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2024-520: Is estimated to be between 1,080 and 1,130 years old. The crater is approximately 36 m (118 ft) in diameter and 9 m (30 ft) deep, is heavily forested and was discovered in 2007 when a metal detector revealed fragments of meteoric iron scattered around the area. A Chinese record states that 10,000 people were killed in the 1490 Qingyang event with the deaths caused by a hail of "falling stones"; some astronomers hypothesize that this may describe an actual meteorite fall, although they find

2116-424: Is formed from its constituents, heat may either be absorbed or released. The quantity of heat absorbed or given off during transformation is called the heat of formation . Heats of formations for solids and gases found in explosive reactions have been determined for a temperature of 25 °C and atmospheric pressure, and are normally given in units of kilojoules per gram-molecule. A positive value indicates that heat

2208-453: 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

2300-496: Is normally associated with large impact events 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. Chromium isotopic ratios are homogeneous within the earth, and therefore these isotopic anomalies exclude

2392-506: Is now Western Australia ), dated at more than 2.2 billion years ago with the impactor estimated to be around 7 kilometres (4.3 mi) wide. It is believed that, at this time, the Earth was mostly or completely frozen, commonly called the Huronian glaciation . The Vredefort impact event , which occurred around 2 billion years ago in Kaapvaal Craton (what is now South Africa ), caused

2484-413: Is officially defined as "the weight of a lead sphere that is just supported by a tube that the rocket motor will just fit into." Explosion An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy , usually with the generation of high temperatures and release of high-pressure gases . Explosions may also be generated by

2576-546: 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 Earth. This iridium layer at the Cretaceous–Paleogene boundary has been found worldwide at 100 different sites. Multidirectionally shocked quartz (coesite), which

2668-522: Is the only known such incident in modern times to result in numerous injuries. Its meteor is the largest recorded object to have encountered the Earth since the Tunguska event. The Comet Shoemaker–Levy 9 impact provided the first direct observation of an extraterrestrial collision of Solar System objects, when the comet broke apart and collided with Jupiter in July 1994. An extrasolar impact was observed in 2013, when

2760-407: Is the rapid liberation of heat that causes the gaseous products of most explosive reactions to expand and generate high pressures . This rapid generation of high pressures of the released gas constitutes the explosion. The liberation of heat with insufficient rapidity will not cause an explosion. For example, although a unit mass of coal yields five times as much heat as a unit mass of nitroglycerin ,

2852-469: The Deccan Traps . 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. Impacts of projectiles as large as one 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

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2944-519: The Earth , there can be significant physical and biospheric consequences, as the impacting body is usually traveling at several kilometres a second (a minimum of 11.2 km/s (7.0 mi/s) for an Earth impacting body ), though atmospheres mitigate many surface impacts through atmospheric entry . Impact craters and structures are dominant landforms on many of the Solar System 's solid objects and present

3036-691: The Lonar crater lake in India, approximately 52,000 years old (though a study published in 2010 gives a much greater age), which now has a flourishing semi-tropical jungle around it. The Rio Cuarto craters in Argentina were produced approximately 10,000 years ago, at the beginning of the Holocene. If proved to be impact craters, they would be the first impact of the Holocene. The Campo del Cielo ("Field of Heaven") refers to an area bordering Argentina's Chaco Province where

3128-566: The Tunguska event of 1908 is believed to have resulted from a meteor air burst . Black hole mergers, likely involving binary black hole systems, are capable of radiating many solar masses of energy into the universe in a fraction of a second, in the form of a gravitational wave . This is capable of transmitting ordinary energy and destructive forces to nearby objects, but in the vastness of space, nearby objects are rare. The gravitational wave observed on 21 May 2019, known as GW190521 , produced

3220-403: The cube of the resulting crater's diameter, which is on average proportional to the diameter of the impactor. Asteroids with a 1 km (0.62 mi) diameter strike Earth every 500,000 years on average. Large collisions – with 5 km (3 mi) objects – happen approximately once every twenty million years. The last known impact of an object of 10 km (6 mi) or more in diameter

3312-412: The dynamo mechanism at a planet's core responsible for maintaining the magnetic field of the planet , and may have contributed to Mars' lack of current magnetic field. An impact event may cause a mantle plume ( volcanism ) at the antipodal point of the impact. The Chicxulub impact may have increased volcanism at mid-ocean ridges and has been proposed to have triggered flood basalt volcanism at

3404-545: The formation of the Earth–Moon system , the evolutionary history of life , the origin of water on Earth , and several mass extinctions . Impact structures are the result of impact events on solid objects and, as the dominant landforms on many of the System's solid objects, present the most solid evidence of prehistoric events. Notable impact events include the hypothesized Late Heavy Bombardment , which would have occurred early in

3496-442: The "heat of explosion." A chemical explosive is a compound or mixture which, upon the application of heat or shock, decomposes or rearranges with extreme rapidity, yielding much gas and heat. Many substances not ordinarily classed as explosives may do one, or even two, of these things. A reaction must be capable of being initiated by the application of shock, heat, or a catalyst (in the case of some explosive chemical reactions) to

3588-651: The Big Questions that an asteroid collision was the biggest threat to the planet. In June 2018, the US National Science and Technology Council warned that America is unprepared for an asteroid impact event, and has developed and released the "National Near-Earth Object Preparedness Strategy Action Plan" to better prepare. According to expert testimony in the United States Congress in 2013, NASA would require at least five years of preparation before

3680-483: The Chelyabinsk meteor airburst event over Russia in 2013. In 2005 it was estimated that the chance of a single person born today dying due to an impact is around 1 in 200,000. The two to four-meter-sized asteroids 2008 TC 3 , 2014 AA , 2018 LA , 2019 MO , 2022 EB5 , and the suspected artificial satellite WT1190F are the only known objects to be detected before impacting the Earth. Impacts have had, during

3772-568: The Cretaceous–Paleogene extinction event, scientists believe that the impactor was a metallic asteroid with a diameter in the order of 1.5 kilometres (0.9 mi). The impact would have had global effects. 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. Significant examples of Pleistocene impacts include

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3864-596: The Earth in the Sikhote-Alin Mountains , Primorye , Soviet Union. It was during daytime hours and was witnessed by many people, which allowed V. G. Fesenkov , then chairman of the meteorite committee of the USSR Academy of Science, to estimate the meteoroid's orbit before it encountered the Earth. Sikhote-Alin is a massive fall with the overall size of the meteoroid estimated at 90,000 kg (200,000 lb). A more recent estimate by Tsvetkov (and others) puts

3956-586: 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 leave a crater almost 100 km (60 mi) across. Only three confirmed craters from that time period with that size or greater have been found: Chicxulub , Popigai , and Manicouagan , and all three have been suspected of being linked to extinction events though only Chicxulub,

4048-497: The Earth's crust pose significant challenges to conclusively identifying impacts from this period. Only two pieces of pristine lithosphere are believed to remain from this era: Kaapvaal Craton (in contemporary South Africa) and Pilbara Craton (in contemporary Western Australia) to search within which may potentially reveal evidence in the form of physical craters. Other methods may be used to identify impacts from this period, for example, indirect gravitational or magnetic analysis of

4140-503: The Earth's surface, a theory known as exogenesis . These modified views of 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 , east of Flagstaff, Arizona, are rare. Instead, it

4232-592: The Hindu festival of Diwali , and are sold in the millions. Skyrockets were officially banned in Norway starting from the new years eve of 2008/09. Skyrockets are strictly forbidden, and carry heavy fines for anyone who are caught launching them. In the Philippines , Republic Act 7183 was enacted to regulate and to control the sale, distribution, manufacture and use of fireworks and firecrackers for public safety . According to

4324-678: The Moon's origin is the giant impact theory, which postulates that Earth was once hit by a planetoid the size of Mars; such a theory is able to explain the size and composition of the Moon, something not done by other theories of lunar formation. According to the theory of the Late Heavy Bombardment , there should have been 22,000 or more impact craters with diameters >20 km (12 mi), about 40 impact basins with diameters about 1,000 km (620 mi), and several impact basins with diameters about 5,000 km (3,100 mi). However, hundreds of millions of years of deformation at

4416-630: The Permian-Triassic extinction is still a matter of debate; the age and origin of proposed impact craters, i.e. the Bedout High structure, hypothesized to be associated with it are still controversial. The last such mass extinction led to the demise of the non-avian 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), which occurred 66 million years ago. There

4508-492: 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 20th century, a large number of highly modified impact craters began to be identified. The first direct observation of a major impact event occurred in 1994: the collision of the comet Shoemaker-Levy 9 with Jupiter . Based on crater formation rates determined from

4600-567: The Sun, and presumably on most other stars as well. The energy source for solar flare activity comes from the tangling of magnetic field lines resulting from the rotation of the Sun's conductive plasma. Another type of large astronomical explosion occurs when a meteoroid or an asteroid impacts the surface of another object, or explodes in its atmosphere , such as a planet. This occurs because the two objects are moving at very high speed relative to each other (a minimum of 11.2 kilometres per second (7.0 mi/s) for an Earth impacting body ). For example,

4692-577: The air, not rockets. Bottle rockets are specifically illegal in many jurisdictions, even those where most other consumer fireworks are legal. They are sometimes considered to present a unique hazard, due to their ability to fly in many directions other than vertically. Bottle rockets are banned under the Explosives Act , thus making importation, possession, transportation, storage or manufacturing illegal in Canada . In India, bottle rockets are set off during

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4784-466: 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 km (830 sq mi). In February 1947, another large bolide impacted

4876-639: The biosphere has been the subject of scientific debate. Several theories of impact-related mass extinction have been developed. In the past 500 million years there have been five generally accepted major mass extinctions that on average extinguished half of all species . One of the largest mass extinctions to have affected life on Earth was the Permian-Triassic , which ended the Permian period 250 million years ago and killed off 90 percent of all species; life on Earth took 30 million years to recover. The cause of

4968-452: The box (but more commonly by the pack, or by the gross, a packet of 144 rockets) for less than US$ 0.20 each. A bottle rocket consists of three major parts including: A common misconception about professional fireworks displays is that skyrockets are used to propel the pyrotechnic effects into the air. In reality, skyrockets are more widely used as a consumer item. Professional fireworks displays utilize mortars to fire aerial shells into

5060-467: The building blocks for life (the panspermia theory relies on this premise). Impacts have been suggested as the origin of water on Earth . They have also been implicated in several mass extinctions . The prehistoric Chicxulub impact , 66 million years ago, is believed to not only be the cause of the Cretaceous–Paleogene extinction event but acceleration of the evolution of mammals , leading to their dominance and, in turn, setting in place conditions for

5152-410: The burning substance into heat released to the surroundings, while in the latter, fast combustion ( i.e. detonation ) instead converts more internal energy into work on the surroundings ( i.e. less internal energy converted into heat); c.f. heat and work (thermodynamics) are equivalent forms of energy. See Heat of Combustion for a more thorough treatment of this topic. When a chemical compound

5244-429: The casing surrounding the explosive, and/or any other loose miscellaneous items not vaporized by the shock wave from the explosion. High velocity, low angle fragments can travel hundreds of metres with enough energy to initiate other surrounding high explosive items, injure or kill personnel, and/or damage vehicles or structures. Classical Latin explōdō means "to hiss a bad actor off the stage", "to drive an actor off

5336-414: The coal cannot be used as an explosive (except in the form of coal dust ) because the rate at which it yields this heat is quite slow. In fact, a substance that burns less rapidly ( i.e. slow combustion ) may actually evolve more total heat than an explosive that detonates rapidly ( i.e. fast combustion ). In the former, slow combustion converts more of the internal energy ( i.e. chemical potential ) of

5428-576: 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 , which can cause destruction both at sea and on land along the coast, but this is disputed. The Eltanin impact into the Pacific Ocean 2.5 Mya is thought to involve an object about 1 to 4 kilometres (0.62 to 2.49 mi) across but remains craterless. The effect of impact events on

5520-469: 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. The leading theory of

5612-407: The eventual rise of humans . Throughout recorded history, hundreds of Earth impacts (and exploding bolides ) have been reported, with some occurrences causing deaths, injuries, property damage, or other significant localised consequences. One of the best-known recorded events in modern times was the Tunguska event , which occurred in Siberia , Russia, in 1908. The 2013 Chelyabinsk meteor event

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5704-428: The explosion resulting from the released (initially liquid and then almost instantaneously gaseous) propane in the presence of an ignition source. For this reason, emergency workers often differentiate between the two events. In addition to stellar nuclear explosions , a nuclear weapon is a type of explosive weapon that derives its destructive force from nuclear fission or from a combination of fission and fusion. As

5796-501: The festivals are Bang Fai rockets which can be up to 20 metres long and charged with up to 500 kg of black powder . In the United Kingdom firework rockets are sold by weight, e.g.: 4 oz (110 g), 8 oz (230 g), 1 lb. This is not the weight of the rocket itself, but rather of a lead sphere whose diameter matches that of the rocket motor. Rocket weight in the UK

5888-644: 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 Příbram fall, other nations established automated observing programs aimed at studying infalling meteorites. One of these was the Prairie Meteorite Network , operated by the Smithsonian Astrophysical Observatory from 1963 to 1975 in

5980-617: The globe. Two 10-kilometre sized asteroids are now believed to have struck Australia between 360 and 300 million years ago at the Western Warburton and East Warburton Basins , creating a 400-kilometre impact zone. According to evidence found in 2015, it is the largest ever recorded. A third, possible impact was also identified in 2015 to the north, on the upper Diamantina River , also believed to have been caused by an asteroid 10 km across about 300 million years ago, but further studies are needed to establish that this crustal anomaly

6072-449: The ground to become meteorites. An estimated 500 meteorites reach the surface each year, but only 5 or 6 of these typically create a weather radar signature with a strewn field large enough to be recovered and be made known to scientists. The late Eugene Shoemaker of the U.S. Geological Survey estimated the rate of Earth impacts, concluding that an event about the size of the nuclear weapon that destroyed Hiroshima occurs about once

6164-495: The history of the Earth, a significant geological and climatic influence. The Moon 's existence 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

6256-406: The history of the Earth–Moon system, and the confirmed Chicxulub impact 66 million years ago, believed to be the cause of the Cretaceous–Paleogene extinction event . Small objects frequently collide with Earth. There is an inverse relationship between the size of the object and the frequency of such events. The lunar cratering record shows that the frequency of impacts decreases as approximately

6348-427: The impact. Such effects can be shock waves, heat radiation, the formation of craters with associated earthquakes, and tsunamis if bodies of water are hit. Human populations are vulnerable to these effects if they live within the affected zone. Large seiche waves arising from earthquakes and large-scale deposit of debris can also occur within minutes of impact, thousands of kilometres from impact. Stony asteroids with

6440-462: The largest known still existing craters/impact structures on Earth, with the impactors having estimated diameters of ~20–50 kilometres (12–31 mi), with the craters generated by these impacts having an estimated diameter of 400–1,000 kilometres (250–620 mi). The largest impacts like those represented by the S2 layer are likely to have had far-reaching effects, such as the boiling of the surface layer of

6532-404: The largest of the three, has been consistently considered. The impact that caused Mistastin crater generated temperatures exceeding 2,370 °C, the highest known to have occurred on the surface of the Earth. Besides the direct effect of asteroid impacts on a planet's surface topography, global climate and life, recent studies have shown that several consecutive impacts might have an effect on

6624-475: The largest verified crater, a multi-ringed structure 160–300 km (100–200 mi) across, forming from an impactor approximately 10–15 km (6.2–9.3 mi) in diameter. The Sudbury impact event occurred on the Nuna supercontinent (now Canada ) from a bolide approximately 10–15 km (6.2–9.3 mi) in diameter approximately 1.849 billion years ago Debris from the event would have been scattered across

6716-411: The magma rises causes the gas to bubble out of solution, resulting in a rapid increase in volume, however the size of the magma chamber remains the same. This results in pressure buildup that eventually leads to an explosive eruption. Explosions can also occur outside of Earth in the universe in events such as supernovae , or, more commonly, stellar flares. Humans are also able to create explosions through

6808-427: The mantle, but may prove inconclusive. In 2021, evidence for a probable impact 3.46 billion-years ago at Pilbara Craton has been found in the form of a 150 kilometres (93 mi) crater created by the impact of a 10 kilometres (6.2 mi) asteroid (named "The Apex Asteroid") into the sea at a depth of 2.5 kilometres (1.6 mi) (near the site of Marble Bar, Western Australia ). The event caused global tsunamis. It

6900-528: The mass at around 100,000 kg (220,000 lb). It was an iron meteorite belonging to the chemical group IIAB and with a coarse octahedrite structure. More than 70 tonnes ( metric tons ) of material survived the collision. A case of a human injured by a space rock occurred on November 30, 1954, in Sylacauga, Alabama . 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

6992-615: The midwestern U.S. This program also observed a meteorite fall, the "Lost City" chondrite, allowing its recovery and a calculation of its orbit. Another program in Canada, the Meteorite Observation and Recovery Project, ran from 1971 to 1985. It too recovered a single meteorite, "Innisfree", in 1977. Finally, observations by the European Fireball Network, a descendant of the original Czech program that recovered Příbram, led to

7084-423: The minimum impact velocity is 11 km/s with asteroid impacts averaging around 17 km/s on the Earth. The most probable impact angle is 45 degrees. Impact conditions such as asteroid size and speed, but also density and impact angle determine the kinetic energy released in an impact event. The more energy is released, the more damage is likely to occur on the ground due to the environmental effects triggered by

7176-571: 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 Penfield 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. This convinced

7268-508: The number of deaths implausible. Kamil Crater , discovered from Google Earth image review in Egypt , 45 m (148 ft) in diameter and 10 m (33 ft) 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. One of

7360-653: The oceans. The Maniitsoq structure , dated to around 3 billion years old (3 Ga), was once thought to be the result of an impact; however, follow-up studies have not confirmed its nature as an impact structure. The Maniitsoq structure is not recognised as an impact structure by the Earth Impact Database . In 2020, scientists discovered the world's oldest confirmed impact crater, the Yarrabubba crater , caused by an impact that occurred in Yilgarn Craton (what

7452-419: The presence of oxygen. Accidental explosions may occur in fuel tanks, rocket engines, etc. A high current electrical fault can create an "electrical explosion" by forming a high-energy electrical arc which rapidly vaporizes metal and insulation material. This arc flash hazard is a danger to people working on energized switchgear . Excessive magnetic pressure within an ultra-strong electromagnet can cause

7544-498: The said law, skyrockets (known in the Philippines as kwitis ) are legal and are designed to propel from 40–50 feet (12–15 m) before exploding. Despite being legal, it poses danger to those using it. In 2012, it was recorded that skyrockets were the second most harmful firecracker after piccolo . In Thailand 's Isan region, many are made by hand and sold in conjunction with Rocket Festivals . The largest bottle rockets used at

7636-490: The size of the Chicxulub crater, which did not result in any mass extinctions, and there is no clear linkage between an impact and any other incident of mass extinction. Paleontologists David M. Raup and Jack Sepkoski have proposed that an excess of extinction events 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

7728-483: The stage by making noise", from ex- ("out") + plaudō ("to clap; to applaud"). The modern meaning developed later: In English: Impact event An impact event is a collision between astronomical objects causing measurable effects. Impact events have been found to regularly occur in planetary systems , though the most frequent involve asteroids , comets or meteoroids and have minimal effect. When large objects impact terrestrial planets such as

7820-446: The strongest empirical evidence for their frequency and scale. Impact events appear to have played a significant role in the evolution of the Solar System since its formation. Major impact events have significantly shaped Earth's history , and have been implicated in the formation of the Earth–Moon system . Impact events also appear to have played a significant role in the evolutionary history of life . Impacts may have helped deliver

7912-430: The use of explosives , or through nuclear fission or fusion , as in a nuclear weapon . Explosions frequently occur during bushfires in eucalyptus forests where the volatile oils in the tree tops suddenly combust. Among the largest known explosions in the universe are supernovae , which occur after the end of life of some types of stars . Solar flares are an example of common, much less energetic, explosions on

8004-535: 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). 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, smaller impacts, some nearing half

8096-522: Was at the Cretaceous–Paleogene extinction event 66 million years ago. The energy released by an impactor depends on diameter, density, velocity, and angle. The diameter of most near-Earth asteroids that have not been studied by radar or infrared can generally only be estimated within about a factor of two, by basing it on the asteroid's brightness. The density is generally assumed, because the diameter and mass, from which density can be calculated, are also generally estimated. Due to Earth's escape velocity ,

8188-627: Was badly bruised by the fragments . Several persons have since claimed to have been struck by "meteorites" but no verifiable meteorites have resulted. A small number of meteorite falls have been observed with automated cameras and recovered following calculation of the impact point. The first was the Příbram meteorite , which fell in Czechoslovakia (now the Czech Republic) in 1959. In this case, two cameras used to photograph meteors captured images of

8280-422: Was correctly identified as 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

8372-474: Was indeed the result of an impact event. The prehistoric Chicxulub impact , 66 million years ago, believed to be the cause of the Cretaceous–Paleogene extinction event, was caused by an asteroid estimated to be about 10 kilometres (6.2 mi) wide. Analysis of the Hiawatha Glacier reveals the presence of a 31 km wide impact crater dated at 58 million years of age, less than 10 million years after

8464-469: 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 48 km or 30 mi 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

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