Impact winter
An impact winter is a hypothesized period of
Possibility of impact
Each year, the Earth is hit by 5 m (16 ft) diameter
Over 300 short-period
Necessary impact factors
The Earth experiences a never-ending barrage of cosmic debris. Small particles burn up as they enter the
Size
A large
Composition
There are three different composition types for an asteroid or comet:
Possible mechanisms
Although the
Mass ejection of regolith
In a study conducted by Curt Covey et al., it was found that an
These pulverized rock particles would remain in the
However, this effect could be largely mitigated, even reversed, by a release of enormous quantities of water vapor and carbon dioxide caused by the initial global heat pulse after the impact. If the asteroid hit an ocean (which would be the case with the majority of impact events), water vapor would form the majority of any ejected matter, and would likely result in a major greenhouse effect and a net increase in temperature.[citation needed]
If the impact event is sufficiently energetic it might cause mantle plume (volcanism) at the antipodal point (the opposite side of the world).[15] This volcanism could alone therefore create a volcanic winter, irrespective of the other impact effects.
Multiple firestorms
In combination with the initial debris ejected into the
Past events
In 2016, a scientific drilling project drilled deep into the
The discoveries were widely seen as confirming current theories related to both the crater impact and its effects. They confirmed that the rock comprising the peak ring had been subjected to immense pressures and forces, and had been melted by immense heat and shocked by immense pressure from its usual state into its present form in just minutes. The fact that the peak ring was made of granite was also significant, since granite is not a rock found in sea-floor deposits – it originates much deeper in the earth and had been ejected to the surface by the immense pressures of impact. Gypsum, a sulfate-containing rock that is usually present in the shallow seabed of the region, had been almost entirely removed and must therefore have been almost entirely vaporized and entered the atmosphere, and that the event was immediately followed by a huge megatsunami (a massive movement of sea waters) sufficient to lay down the largest known layer of sand separated by grain size directly above the peak ring.
These strongly support the hypothesis that the impactor was large enough to create a 120-mile peak ring, eject molten granite from deep within the earth, create colossal water movements, and eject an immense quantity of vaporized rock and sulfates into the atmosphere, where they would have persisted for a long time. This global dispersion of dust and sulfates would have led to a sudden and catastrophic effect on the climate worldwide by causing large temperature drops, devastating the food chain.[16][17]
Impact on humans
An impact winter would have a devastating effect on humans, as well as the other species on Earth. With the
Agriculture
With the
Economics
The cost to clean up after an asteroid or comet impact would cost billions to trillions of dollars, depending on the location impacted.[19][20] An impact in New York City (the 16th most populated city in the world) could cost billions of dollars in financial losses and it could take years for the financial sector (i.e. stock market) to recover.[19] However, the probability of such a naturally specifically aimed impact would be exceedingly low.
Survivability
As of February 20, 2018[update], there are 17,841 near-Earth objects known. 8,059 potentially hazardous objects are known; they are larger than 140 m (460 ft) and may approach the Earth closer than 20 times the distance to the Moon.[6] 888 NEAs larger than 1 km have been discovered,[21] or 96.5% of an estimated total of about 920.[22]
See also
- Asteroid deflection strategies
- Earth Impact Database
- Impact event
- List of notable asteroids
- Near-Earth objects
- Nuclear winter
- Volcanic winter
- Comets in fiction
- Asteroids in fiction
References
- ^ Osterloff, Emily (2018). "How an asteroid ended the age of the dinosaurs". London: Natural History Museum. Archived from the original on 26 April 2022. Retrieved 18 May 2022.
- ^ S2CID 4305299
- ^
- ^ ISBN 978-0-201-48950-7
- ISBN 978-1-55868-522-2.
- ^
- ^ "Sentry Risk Table". NASA/JPL Near-Earth Object Program Office. 9 December 2014. Archived from the original on December 31, 2014. Retrieved 2014-12-10.
- Science Daily. 1 April 2010. Retrieved 5 November 2014.
- ^ Roach, John (7 April 2010). "Comet "Shower" Killed Ice Age Mammals?". National Geographic. Archived from the original on April 10, 2010. Retrieved 5 November 2014.
- ^ Hecht, John (2 April 2010). "Did a comet swarm strike America 13,000 years ago?". New Scientist. Retrieved 5 November 2014.
- ISBN 978-0521853491.
- ^
- S2CID 16017767.
- ^ PMID 11539442
- .
- ^ "Updated: Drilling of dinosaur-killing impact crater explains buried circular hills". 2016-05-03.
- ^ Fleur, Nicholas St (2016-11-17). "Drilling into the Chicxulub Crater, Ground Zero of the Dinosaur Extinction". The New York Times.
- ^ Michael R. Rampino, Stanley H. Ambrose, 2000. "Volcanic winter in the Garden of Eden: The Toba supereruption and the late Pleistocene human population crash", Volcanic Hazards and Disasters in Human Antiquity, Floyd W. McCoy, Grant Heiken
- ^ ISBN 978-3-540-32711-0
- ^ ISBN 978-0-12-446760-6
- ^ "Discovery Statistics – Cumulative Totals". NASA/JPL CNEOS. February 5, 2018. Retrieved 2018-02-08.
- ^ Matt Williams (October 20, 2017). "Good News Everyone! There are Fewer Deadly Undiscovered Asteroids than we Thought". Universe Today. Retrieved 2017-11-14.