Impact event
An impact event is a collision between astronomical objects causing measurable effects.[1] 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 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[2]), 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 the strongest empirical evidence for their frequency and scale.
Impact events appear to have played a significant role in the
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.[5] 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 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 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.[6] Impact events have been a plot and background element in science fiction.
In April 2018, the
Impacts and the Earth
Major impact events have significantly shaped
Frequency and risk
Small objects frequently collide with Earth. There is an
The energy released by an impactor depends on diameter, density, velocity, and angle.
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 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.
Airbursts
Stony asteroids with a diameter of 4 m (13 ft) enter Earth's atmosphere about once a year.
Impactor diameter |
Kinetic energy at | Airburst altitude |
Average frequency (years) |
Recorded fireballs (CNEOS) (1988–2018) | |
---|---|---|---|---|---|
atmospheric entry |
airburst | ||||
4 m (13 ft) | 3 kt | 0.75 kt | 42.5 km (139,000 ft) | 1.3 | 54 |
7 m (23 ft) | 16 kt | 5 kt | 36.3 km (119,000 ft) | 4.6 | 15 |
10 m (33 ft) | 47 kt | 19 kt | 31.9 km (105,000 ft) | 10 | 2 |
15 m (49 ft) | 159 kt | 82 kt | 26.4 km (87,000 ft) | 27 | 1
|
20 m (66 ft) | 376 kt | 230 kt | 22.4 km (73,000 ft) | 60 | 1 |
30 m (98 ft) | 1.3 Mt | 930 kt | 16.5 km (54,000 ft) | 185 | 0 |
50 m (160 ft) | 5.9 Mt | 5.2 Mt | 8.7 km (29,000 ft) | 764 | 0 |
70 m (230 ft) | 16 Mt | 15.2 Mt | 3.6 km (12,000 ft) | 1,900 | 0 |
85 m (279 ft) | 29 Mt | 28 Mt | 0.58 km (1,900 ft) | 3,300 | 0 |
Based on density of 2600 kg/m3, speed of 17 km/s, and an impact angle of 45° |
Impactor diameter |
Kinetic energy at | Crater diameter |
Frequency (years) | |
---|---|---|---|---|
atmospheric entry |
impact | |||
100 m (330 ft) | 47 Mt | 3.4 Mt | 1.2 km (0.75 mi) | 5,200 |
130 m (430 ft) | 103 Mt | 31.4 Mt | 2 km (1.2 mi) | 11,000 |
150 m (490 ft) | 159 Mt | 71.5 Mt | 2.4 km (1.5 mi) | 16,000 |
200 m (660 ft) | 376 Mt | 261 Mt | 3 km (1.9 mi) | 36,000 |
250 m (820 ft) | 734 Mt | 598 Mt | 3.8 km (2.4 mi) | 59,000 |
300 m (980 ft) | 1270 Mt | 1110 Mt | 4.6 km (2.9 mi) | 73,000 |
400 m (1,300 ft) | 3010 Mt | 2800 Mt | 6 km (3.7 mi) | 100,000 |
700 m (2,300 ft) | 16100 Mt | 15700 Mt | 10 km (6.2 mi) | 190,000 |
1,000 m (3,300 ft) | 47000 Mt | 46300 Mt | 13.6 km (8.5 mi) | 440,000 |
Based on ρ = 2600 kg/m3; v = 17 km/s; and an angle of 45° |
Objects with a diameter less than 1 m (3.3 ft) are called
The late
Although no human is known to have been killed directly by an impact[
Geological significance
Impacts have had, during the history of the Earth, a significant geological and climatic influence.[29][30]
The
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
It was not until 1903–1905 that the Barringer Crater was correctly identified as an impact crater, and it was not until as recently as 1963 that research by
Based on crater formation rates determined from the Earth's closest celestial partner, the Moon,
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 the
While numerous impact craters have been confirmed on land or in the shallow seas over
Biospheric effects
The effect of impact events on 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
In 1980, physicist
at levels tens of thousands times normal levels were found with the above.Anomalies in chromium isotopic ratios found within the
Probably the most convincing evidence for a worldwide catastrophe was the discovery of the crater which has since been named
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 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.[42]
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 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 a Nemesis-style periodicity.[49]
Sociological and cultural effects
An impact event is commonly seen as a scenario that would bring about the
A joint
Earth impacts
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 kilometres 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.
Precambrian
The leading theory of 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.[52]
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 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 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).[53] The event caused global tsunamis. It is also coincidental to some of the earliest evidence of life on Earth, fossilized Stromatolites.
Evidence of a massive impact, (named S2; "S" for
The Maniitsoq structure, dated to around 3 billion years old (3 Ga), was once thought to be the result of an impact;[56][57] however, follow-up studies have not confirmed its nature as an impact structure.[57][58][59][60][61][62] The Maniitsoq structure is not recognised as an impact structure by the Earth Impact Database.[63]
In 2020, scientists discovered the world's oldest confirmed impact crater, the
The Vredefort impact event, which occurred around 2 billion years ago in Kaapvaal Craton (what is now South Africa), caused 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.[67][68]
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[69] Debris from the event would have been scattered across the globe.
Paleozoic and Mesozoic
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.[70] 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 was indeed the result of an impact event.[71]
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.[3]
Paleogene
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 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.[72]
Pleistocene
Holocene
The
The
Whitecourt crater in Alberta, Canada 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.[78][79]
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 the number of deaths implausible.[80]
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.[81]
20th-century impacts
One of the best-known recorded impacts in modern times was the Tunguska event, which occurred in Siberia, Russia, in 1908.[82] 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).[83]
In February 1947, another large bolide impacted the Earth in the
A case of a human injured by a space rock occurred on November 30, 1954, in
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.[86] 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 Příbram fall, other nations established automated observing programs aimed at studying infalling meteorites.
On August 10, 1972, a meteor which became known as the 1972 Great Daylight Fireball was witnessed by many people as it moved 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-mm color movie camera.[91] In size range the object was roughly between a car and a house, and while it could have ended its life in a Hiroshima-sized blast, 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.
Many impact events occur without being observed by anyone on the ground. Between 1975 and 1992, American missile
In the dark morning hours of January 18, 2000, a
21st-century impacts
On 7 June 2006, a meteor was observed striking Reisadalen in Nordreisa municipality in Troms County, Norway. 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 to 500 tonnes TNT equivalent, around three percent of Hiroshima's yield.[94]
On 15 September 2007, a chondritic
On 7 October 2008, an approximately 4 m asteroid 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.[95]
On 15 February 2013, an asteroid entered Earth's atmosphere over Russia as a fireball and exploded above the city of Chelyabinsk during its passage through the Ural Mountains region at 09:13 YEKT (03:13 UTC).[96][97] The object's air burst occurred at an altitude between 30 and 50 km (19 and 31 mi) above the ground,[98] and about 1,500 people were injured, mainly by broken window glass shattered by the shock wave. Two were reported in serious condition; however, there were no fatalities.[99] Initially some 3,000 buildings in six cities across the region were reported damaged due to the explosion's shock wave, a figure which rose to over 7,200 in the following weeks.[100][101] The Chelyabinsk meteor was estimated to have caused over $30 million in damage.[102][103] It is the largest recorded object to have encountered the Earth since the 1908 Tunguska event.[104][105] The meteor is estimated to have an initial diameter of 17–20 metres and a mass of roughly 10,000 tonnes. On 16 October 2013, a team from Ural Federal University led by Victor Grokhovsky recovered a large fragment of the meteor from the bottom of Russia's Lake Chebarkul, about 80 km west of the city.[106]
On 1 January 2014, a 3 m (10 ft) asteroid, 2014 AA, was discovered by the Mount Lemmon Survey and observed over the next hour, and was soon found to be on a collision course with Earth. The exact location was uncertain, constrained to a line between Panama, the central Atlantic Ocean, The Gambia, and Ethiopia. Around roughly the time expected (2 January 3:06 UTC) an infrasound burst was detected near the center of the impact range, in the middle of the Atlantic Ocean.[107][108] This marks the second time a natural object was identified prior to impacting earth after 2008 TC3.
Nearly two years later, on October 3, WT1190F was detected orbiting Earth on a highly eccentric orbit, taking it from well within the Geocentric satellite ring to nearly twice the orbit of the Moon. It was estimated to be perturbed by the Moon onto a collision course with Earth on November 13. With over a month of observations, as well as precovery observations found dating back to 2009, it was found to be far less dense than a natural asteroid should be, suggesting that it was most likely an unidentified artificial satellite. As predicted, it fell over Sri Lanka at 6:18 UTC (11:48 local time). The sky in the region was very overcast, so only an airborne observation team was able to successfully observe it falling above the clouds. It is now thought to be a remnant of the Lunar Prospector mission in 1998, and is the third time any previously unknown object – natural or artificial – was identified prior to impact.
On 22 January 2018, an object,
On 2 June 2018, the Mount Lemmon Survey detected 2018 LA (ZLAF9B2), a small 2–5 m asteroid which further observations soon found had an 85% chance of impacting Earth. Soon after the impact, a fireball report from Botswana arrived to the American Meteor Society. Further observations with ATLAS extended the observation arc from 1 hour to 4 hours and confirmed that the asteroid orbit indeed impacted Earth in southern Africa, fully closing the loop with the fireball report and making this the third natural object confirmed to impact Earth, and the second on land after 2008 TC3.[110][111][112]
On 8 March 2019,
2019 MO, an approximately 4 m asteroid, was detected by ATLAS a few hours before it impacted the Caribbean Sea near Puerto Rico in June 2019.[113]
In 2023, a small meteorite is believed to have crashed through the roof of a home in Trenton, New Jersey. The metallic rock was approximately 4 inches by 6 inches and weighed 4 pounds. The item was seized by police and tested for radioactivity.[114] The object was later confirmed to be a meteorite by scientists at The College of New Jersey, as well as meteorite expert Jerry Delaney, who previously worked at Rutgers University and the American Museum of Natural History.[115]
Asteroid impact prediction
In the late 20th and early 21st century scientists put in place measures to detect
Currently prediction is mainly based on cataloging
Current response status
In April 2018, the
Elsewhere in the Solar System
Evidence of massive past impact events
Impact craters provide evidence of past impacts on other planets in the Solar System, including possible interplanetary terrestrial impacts. Without carbon dating, other points of reference are used to estimate the timing of these impact events. Mars provides some significant evidence of possible interplanetary collisions. The
Observed events
Jupiter
Jupiter is the most massive planet in the Solar System, and because of its large mass it has a vast sphere of gravitational influence, the region of space where an asteroid capture can take place under favorable conditions.[123]
Jupiter is able to capture comets in orbit around the Sun with a certain frequency. In general, these comets travel some revolutions around the planet following unstable orbits as highly elliptical and perturbable by solar gravity. While some of them eventually recover a heliocentric orbit, others crash on the planet or, more rarely, on its satellites.[124][125]
In addition to the mass factor, its relative proximity to the inner solar system allows Jupiter to influence the distribution of minor bodies there. For a long time it was believed that these characteristics led the gas giant to expel from the system or to attract most of the wandering objects in its vicinity and, consequently, to determine a reduction in the number of potentially dangerous objects for the Earth. Subsequent dynamic studies have shown that in reality the situation is more complex: the presence of Jupiter, in fact, tends to reduce the frequency of impact on the Earth of objects coming from the Oort cloud,[126] while it increases it in the case of asteroids[127] and short period comets.[128]
For this reason Jupiter is the planet of the Solar System characterized by the highest frequency of impacts, which justifies its reputation as the "sweeper" or "cosmic vacuum cleaner" of the Solar System.[129] 2009 studies suggest an impact frequency of one every 50–350 years, for an object of 0.5–1 km in diameter; impacts with smaller objects would occur more frequently. Another study estimated that comets 0.3 km (0.19 mi) in diameter impact the planet once in approximately 500 years and those 1.6 km (0.99 mi) in diameter do so just once in every 6,000 years.[130]
In July 1994,
The
Later minor impacts were observed by amateur astronomers in 2010, 2012, 2016, and 2017; one impact was observed by Juno in 2020.
Other impacts
In 1998, two comets were observed plunging toward the
In 2010, between January and May,
Around March 27, 2012, based on evidence, there were signs of an impact on Mars. Images from the Mars Reconnaissance Orbiter provide compelling evidence of the largest impact observed to date on Mars in the form of fresh craters, the largest measuring 48.5 by 43.5 meters. It is estimated to be caused by an impactor 3 to 5 meters long.[138]
On March 19, 2013, an impact occurred on the Moon that was visible from Earth, when a boulder-sized 30 cm meteoroid slammed into the lunar surface at 90,000 km/h (25 km/s; 56,000 mph) creating a 20-meter crater.[139][140] NASA has actively monitored lunar impacts since 2005,[141] tracking hundreds of candidate events.[142][143]
On 18 September 2021 an impact event on Mars formed a cluster of craters, the largest being 130m in diameter. On 24 December 2021 an impact created a 150m-wide crater. Debris was ejected up to 35 km (19 miles) from the impact site.[144]
Extrasolar impacts
Collisions between galaxies, or
In 2013, an impact between minor planets was detected around the star NGC 2547 ID 8 by Spitzer and confirmed by ground observations. Computer modelling suggests that the impact involved large asteroids or protoplanets similar to the events believed to have led to the formation of terrestrial planets like the Earth.[6]
See also
- Asteroid capture – Orbital insertion of an asteroid around a larger planetary body
- Asteroid impact avoidance – Methods to prevent destructive asteroid hits
- Asteroids in fiction
- B612 Foundation – Planetary defense nonprofit organization
- Central-peak crater– Large impact craters with uplifted centres
- Earth Impact Database – Database of impact structures on Earth
- Global catastrophic risk – Potentially harmful worldwide events
- Impact events in fiction
- Impact gardening – Effects of astronomic impacts on crusts of moons and planets
- Late Heavy Bombardment – Hypothesized astronomical event
- List of bolides
- List of impact craters on Earth
- List of possible impact structures on Earth
- Meteor air burst – Atmospheric explosion of a meteor
- Near-Earth asteroids– Small Solar System body with an orbit that can bring it close to Earth
- Near-Earth object – Small Solar System body with an orbit that can bring it close to Earth
- Near-Earth Object Camera– Space-based infrared telescope
- Palermo Technical Impact Hazard Scale – Logarithmic scale in astronomy
- Pan-STARRS – Multi-telescope astronomical survey
- Peak ring (crater)– Roughly circular ring or plateau, possibly discontinuous, surrounding an impact crater's center
- Potentially hazardous object – Hazardous near-Earth asteroid or comet
- Spaceguard – Efforts to study asteroids that might impact Earth
- Torino scale – Measure for the hazard from asteroids and comets, 0 to 10
References
- ^ S2CID 34867206.
- ^ Koeberl, Christian; Sharpton, Virgil L. "Terrestrial Impact Craters, Second Edition". Lunar and Planetary Institute. Retrieved 2024-01-27.
- ^ PMID 11857903.
- PMID 34765124.
- ISBN 978-0201489507
- ^ a b Wall, Mike (August 28, 2014). "Smash! Aftermath of Colossal Impact Spotted Around Sunlike Star". Space.com.
- ^ a b Homer, Aaron (28 April 2018). "Earth Will Be Hit by an Asteroid with 100 Percent Certainty, Says Space-Watching Group B612 – The group of scientists and former astronauts is devoted to defending the planet from a space apocalypse". Inquisitr. Archived from the original on 24 January 2020. Retrieved 28 April 2018.
- ^ a b Stanley-Becker, Isaac (15 October 2018). "Stephen Hawking feared race of 'superhumans' able to manipulate their own DNA". The Washington Post. Retrieved 26 November 2018.
- ^ a b Haldevang, Max de (14 October 2018). "Stephen Hawking left us bold predictions on AI, superhumans, and aliens". Quartz. Retrieved 26 November 2018.
- ^ a b Bogdan, Dennis (18 June 2018). "Comment – Better Way To Avoid Devastating Asteroids Needed?". The New York Times. Retrieved 26 November 2018.
- ^ National Archives.
- ^ a b Mandelbaum, Ryan F. (21 June 2018). "America Isn't Ready to Handle a Catastrophic Asteroid Impact, New Report Warns". Gizmodo. Retrieved 22 June 2018.
- ^ .
- ^ a b Chang, Kenneth (14 June 2018). "Asteroids and Adversaries: Challenging What NASA Knows About Space Rocks – Two years ago, NASA dismissed and mocked an amateur's criticisms of its asteroids database. Now Nathan Myhrvold is back, and his papers have passed peer review". The New York Times. Retrieved 22 June 2018.
- ^ a b Chang, Kenneth (14 June 2018). "Asteroids and Adversaries: Challenging What NASA Knows About Space Rocks – Relevant Comments". The New York Times. Retrieved 22 June 2018.
- ^ a b U.S.Congress (Spring 2013). "Threats From Space: a Review of U.S. Government Efforts to Track and mitigate Asteroids and Meteors (Part I and Part II) – Hearing Before the Committee on Science, Space, and Technology House of Representatives One Hundred Thirteenth Congress First Session" (PDF). United States Congress (Hearings held 19 March 2013 and 10 April 2013). p. 147. Retrieved 3 May 2014.
- S2CID 118171810.
- ^ a b Paine, Michael; Peiser, Benny (2002). "The Frequency and Consequences of Cosmic Impacts Since the Demise of the Dinosaurs". Bioastronomy 2002: Life Among the Stars.
- ^ Bostrom, Nick (March 2002), "Existential Risks: Analyzing Human Extinction Scenarios and Related Hazards", Journal of Evolution and Technology, 9
- ^ a b c d e f g h Robert Marcus; H. Jay Melosh; Gareth Collins (2010). "Earth Impact Effects Program". Imperial College London / Purdue University. Retrieved 2013-02-04. (solution using 2600kg/m^3, 17km/s, 45 degrees)
- ^ Robert Sanders (February 7, 2013). "New evidence comet or asteroid impact was last straw for dinosaurs". UC Berkeley News Center. Retrieved 2013-02-11.
- Robert DePalma et al., published 1 April 2019.)
- S2CID 4305299
- ^ ["Число пострадавших при падении метеорита приблизилось к 1500" (in Russian). РосБизнесКонсалтинг. Retrieved 25 February 2013.]
- ^ "The word: Torino scale". New Scientist. 25 October 2005. p. 56.
- ^ [Roylance, Frank (2008-10-07). "Predicted meteor may have been sighted". MarylandWeather. Archived from the original on 10 October 2008. Retrieved 2008-10-08.]
- ^ "The First Discovered Asteroid of 2014 Collides With The Earth – An Update". NASA/JPL. 3 January 2014. Archived from the original on 11 February 2017. Retrieved 11 January 2014.
- ^ "Small-Body Database Lookup". Ssd.jpl.nasa.gov. Retrieved 2022-03-16.
- ^ French, B. M. (1998). Traces of catastrophe: A handbook of shock-metamorphic effects in terrestrial meteorite impact structures.
- S2CID 16017767.
- S2CID 4413525. Archived from the original(PDF) on July 30, 2010. Retrieved 2011-12-10.
- ^ "Russia's Popigai Meteor Crash Linked to Mass Extinction". Live Science. June 13, 2014.
- .
- ^ Dvorsky, George (2017-09-17). "The Hottest Known Temperature On Earth Was Caused By An Ancient Asteroid Strike". Gizmodo. Retrieved 2017-09-17.
- ^ Grossman, Lisa. "Multiple Asteroid Strikes May Have Killed Mars's Magnetic Field". Archived from the original on December 30, 2013 – via www.wired.com.
- .
- PMID 29441360.
- S2CID 3463018.
- ^ Dypvik, Henning; Burchell, Mark; Claeys, Philippe. "Impacts into Marine and Icy Environments: A Short Review in Cratering in Marine Environments and on Ice".
{{cite journal}}
: Cite journal requires|journal=
(help) - ^ Gault, D. E.; Sonnet, C. P.; Wedekind, J. A. (1979). "Tsunami Generation by Pelagic Planetoid Impact". Lunar and Planetary Science Conference Abstract.
- Bibcode:2003LPI....34.2013M.
- ^ S2CID 39063747.
- ^ "extinction". math.ucr.edu.
- PMID 18198148
- .
- S2CID 23476732.
- PMID 9794759.
- ^ Penfield, December 2019 Glen (2019-12-01). "Unlikely Impact". AAPG Explorer. Retrieved 2020-08-17.
{{cite web}}
: CS1 maint: numeric names: authors list (link) - S2CID 7911150
- ^ "Twenty ways the world could end suddenly". Discover.
- ^ "Public sees a future full of promise and peril" (PDF). Archived from the original on 2011-02-04. Retrieved 2014-07-11.
{{cite web}}
: CS1 maint: bot: original URL status unknown (link) - .
- S2CID 234265636
- ^ Achenbach, Joel (19 December 2023). "Giant space rock made Earth's ocean boil but also helped early life". The Washington Post. Archived from the original on 19 December 2023. Retrieved 19 December 2023.
- ^ "Scientists reconstruct ancient impact that dwarfs dinosaur-extinction blast". AGU Newsroom.
- .
- ^ doi:10.1016/j.epsl.2013.04.014 – via Elsevier Science Direct.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - S2CID 128625029.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - S2CID 135213870.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - S2CID 134027320.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - S2CID 213973363.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - hdl:10023/20744.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - ^ "Earth Impact Database". www.passc.net. Retrieved 2020-09-30.
- ^ Kornel, Katherine (21 January 2020). "Earth's Oldest Asteroid Impact Found in Australia – The cataclysm, which occurred roughly 2.2 billion years ago, might have catapulted the planet out of an ice age". The New York Times. Retrieved 22 January 2020.
- PMID 31964860.
- PMID 31964860.
- ^ "Vredefort". Earth Impact Database. Planetary and Space Science Centre University of New Brunswick Fredericton. Retrieved 2008-12-30.
- ^ "Deep Impact – The Vredefort Dome". Hartebeesthoek Radio Astronomy Observatory. 2006-08-01. Retrieved 2007-09-19.
- .
- ^ "World's largest asteroid impact found in Australia". Australian Geographic. March 24, 2015.
- ^ "Potential asteroid impact identified in western Queensland". Geoscience Australia. 2015-03-17. Retrieved 26 June 2016.
- PMID 30443592.
- ^ "Handaxe and Tektites from Bose, China". The Smithsonian Institution's Human Origins Program. Archived from the original on October 8, 2014.
- ^ "Asia's oldest axe tools discovered". BBC News. March 3, 2000.
- .
- ^ "Four arrested in Argentina smuggling more than ton of meteorites". news.yahoo.com.
- ^ "Henbury Meteorites Conservation Reserve". 2018-12-17.
- ^ "Whitecourt". Archived from the original on 2017-07-18. Retrieved 2017-07-28.
- ^ "Whitecourt Star". Archived from the original on 2016-03-05.
- .
- ^ USGS Meteoritical Society, Bulletin database, Gebel Kamil Crater ... http://www.lpi.usra.edu/meteor/metbull.php?code=52031
- ^ "Tunguska event | Summary, Cause, & Facts". Encyclopedia Britannica. Retrieved 2021-09-25.
- ^ Hogenboom, Melissa. "In Siberia in 1908, a huge explosion came out of nowhere". Retrieved 2017-03-30.
- Bibcode:1996Met.....2....8G. Archived from the originalon 2010-06-12.
- ^ Meteorite Hits Page Archived August 31, 2009, at the Wayback Machine
- Bibcode:1961BAICz..12...21C
- ^ Gritsevich, M.I. The Pribram, Lost City, Innisfree, and Neuschwanstein falls: An analysis of the atmospheric trajectories. Sol Syst Res 42, 372–390 (2008). https://doi.org/10.1134/S003809460805002X
- S2CID 140675097
- S2CID 121255827
- YouTube
- ^ "Collisions with Near Earth Objects". www.aerospaceweb.org.
- ^ Satellite Study Establishes Frequency of Megaton-sized Asteroid Impacts (SpaceRef November 20, 2002)
- ^ Norway Impact Gentler Than Atomic Bomb (Sky & Telescope June 16, 2006)
- ^ First-Ever Asteroid Tracked From Space to Earth, Wired, March 25, 2009 Archived March 21, 2014, at the Wayback Machine
- ^ "Russian Meteor". NASA. Archived from the original on 18 February 2013. Retrieved 15 February 2013.
- ^ Arutunyan, Anna; Bennetts, Marc (15 February 2013). "Meteor in central Russia injures at least 500". USA Today. Retrieved 15 February 2013.
- ^ "Meteor falls in Russia, 700 injured by blasts". Associated Press. Archived from the original on 18 February 2013. Retrieved 15 February 2013.
- ^ Метеоритный дождь над Уралом: пострадали 1200 человек. Vesti (in Russian). RU. 15 February 2013. Retrieved 15 February 2013.
- ^ Marson, James; Gautam Naik. "Meteorite Hits Russia, Causing Panic". Wall Street Journal. Retrieved 15 February 2013.
- ^ Ewait, David. "Exploding Meteorite Injures A Thousand People In Russia". Forbes. Retrieved 15 February 2013.
- ^ Andrey Kuzmin (16 February 2013). "Meteorite explodes over Russia, more than 1,000 injured". Reuters. Archived from the original on 6 March 2016. Retrieved 16 February 2013.
- ^ "Meteorite-caused emergency situation regime over in Chelyabinsk region". Russia Beyond The Headlines. Rossiyskaya Gazeta. Interfax. 5 March 2013. Archived from the original on 23 June 2013. Retrieved 6 March 2013.
- ^ "Asteroid impacts – How to avert Armageddon". The Economist. 15 February 2013. Retrieved 16 February 2013.
- ^ Kenneth Chang (15 February 2013). "Size of Blast and Number of Injuries Are Seen as Rare for a Rock From Space". The New York Times. Retrieved 16 February 2013.
- ISSN 1832-0457.
- .
- S2CID 119251345.
- ^ Bill Gray MPML[dead link]
- S2CID 119325928.
- S2CID 119208392.
- S2CID 119538516.
- ^ "Breakthrough: UH team successfully locates incoming asteroid". Institute for Astronomy – University of Hawaii. 25 June 2019. Retrieved 12 March 2023.
- AP News. May 9, 2023. Retrieved May 10, 2023.
- AP News. May 11, 2023. Retrieved May 14, 2023.
- YouTube
- ^ "Sentry: Earth Impact Monitoring". Jet Propulsion Laboratory. NASA. Retrieved 25 August 2018.
- ^ "Update to Determine the Feasibility of Enhancing the Search and Characterization of NEOs" (PDF). Near-Earth Object Science Definition Team Report 2017. NASA. Retrieved 7 July 2018.
- ^ Johns Hopkins University (4 March 2019). "Asteroids are stronger, harder to destroy than previously thought". Phys.org. Retrieved 4 March 2019.
- S2CID 127119234.
- ^ Andrews, Robin George (8 March 2019). "If We Blow Up an Asteroid, It Might Put Itself Back Together – Despite what Hollywood tells us, stopping an asteroid from creating an extinction-level event by blowing it up may not work". The New York Times. Retrieved 9 March 2019.
- S2CID 54498331.
- Bibcode:1964SvA.....7..618C.
- Bibcode:1990A&A...239..375T.
- S2CID 14201751. Archived from the original(PDF) on 2013-02-26.
- S2CID 1103987.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - S2CID 8870726.
- S2CID 8032181.
- ^ Dennis Overbye (2009). "Jupiter: Our Cosmic Protector?". The New York Times. p. WK7.
- .
- National Space Science Data Center. February 2005. Retrieved 2008-08-26.
- ^ "Mystery impact leaves Earth-sized mark on Jupiter". CNN. July 21, 2009.
- ^ Overbye, Dennis (July 22, 2009). "All Eyepieces on Jupiter After a Big Impact". New York Times.
- ^ Amateur astronomer spots Earth-size scar on Jupiter, Guardian, July 21, 2009
- ^ "SOHO Hotshots". sohowww.nascom.nasa.gov. Retrieved 2019-01-23.
- ^ "A SOHO and Sungrazing Comet FAQ". home.earthlink.net. Archived from the original on 2012-08-05. Retrieved 2019-01-23.[self-published source]
- ^ Hubble finds that a bizarre X-shaped intruder is linked to an unseen asteroid collision, www.spacetelescope.org October 13, 2010.
- ^ mars.nasa.gov. "NASA Mars Weathercam Helps Find Big New Crater". NASA's Mars Exploration Program. Retrieved 2019-01-23.
- ^ "NASA Announces Brightest Lunar Explosion Ever Recorded". National Geographic Society Newsroom. 2013-05-17. Archived from the original on November 27, 2018. Retrieved 2019-01-23.
- ^ Kramer, Miriam; May 22, Space com Staff Writer |; ET, 2013 12:09pm (22 May 2013). "Moon Crash Scene Investigation Tonight: See Telescope Views of Meteorite Impact". Space.com. Retrieved 2019-01-23.
{{cite web}}
: CS1 maint: numeric names: authors list (link) - ^ Mohon, Lee (2017-02-13). "Lunar Impacts". NASA. Archived from the original on 2018-12-23. Retrieved 2019-01-23.
- ^ "NASA Marshall Space Flight Center (MSFC) – Automated Lunar and Meteor Observatory (ALaMO) – Candidate lunar impact observation database" (PDF). Archived from the original (PDF) on 2013-04-06. Retrieved 2013-05-27.
- ^ Marshall, Spaceflight Center. "List of lunar impact events" (PDF). Archived from the original (PDF) on 2020-08-01. Retrieved 2019-01-23.
- ^ Amos, Jonathan (27 October 2022). "Nasa space probes document big impacts on Mars". BBC News. Archived from the original on 28 October 2022. Retrieved 28 October 2022.
Further reading
- Alvarez, L. W.; Alvarez, W.; Asaro, F.; Michel, H. V. (1980), "Extraterrestrial Cause for the Cretaceous-Tertiary Extinction", S2CID 16017767
- Benton, Michael J. (2003), When Life Nearly Died: The Greatest Mass Extinction of All Time, New York: Thames and Hudson, ISBN 978-0500051160
- Brown, P. G.; Assink, J. D.; Astiz, L.; Blaauw, R.; Boslough, M. B.; Borovička, J.; Brachet, N.; Brown, D.; Campbell-Brown, M.; Ceranna, L.; Cooke, W.; de Groot-Hedlin, C.; Drob, D. P.; Edwards, W.; Evers, L. G.; Garces, M.; Gill, J.; Hedlin, M.; Kingery, A.; Laske, G.; Le Pichon, A.; Mialle, P.; Moser, D. E.; Saffer, A.; Silber, E.; Smets, P.; Spalding, R. E.; Spurný, P.; Tagliaferri, E.; et al. (2013). "A 500-kiloton airburst over Chelyabinsk and an enhanced hazard from small impactors". S2CID 4450349.
- Smit, J.; Hertogen, J. (1980), "An extraterrestrial event at the Cretaceous-Tertiary boundary", S2CID 4339429
- Stone, R. (August 2008), "Target earth", National Geographic Magazine, archived from the originalon July 18, 2008
- Yau, Kevin; Weissman, Paul; Yeomans, Donald (1994). "Meteorite falls in China and some related human casualty events". ISSN 0026-1114.
External links
- Earth Impact Database
- Earth Impact Effects Program Estimates crater size and other effects of a specified body colliding with Earth.
- Exploring North American Impact Craters