Editing Impact event (section)

===Observed events===

====Jupiter====
[[File:Impact site of fragment G.png|thumb|[[Comet Shoemaker-Levy 9]]'s scar on Jupiter (dark area near Jupiter's [[wikt:limb#Etymology 2|limb]])]]
{{Main|Impact events on Jupiter}}
{{See also|List of Jupiter events}}

[[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.<ref>{{cite journal|first=G.A. |last=Chebotarev |title=Gravitational Spheres of the Major Planets, Moon and Sun |journal=Soviet Astronomy |volume=7 |page=620 |url= http://adsabs.harvard.edu/full/1964SvA.....7..618C |year=1964|bibcode=1964SvA.....7..618C }}</ref>

Jupiter is able to capture [[comet]]s 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.<ref>{{cite journal|last=Tancredi |first=G. |year=1990 |title=Temporary Satellite Capture and Orbital Evolution of Comet P/Helin-Roman-Crockett |journal=Astronomy and Astrophysics |volume=239 |issue=1–2 |bibcode=1990A&A...239..375T |pages=375–380 |url=http://adsabs.harvard.edu/abs/1990A%26A...239..375T }}</ref><ref>{{cite journal|last=Ohtsuka |first=Katsuhito|title=Quasi-Hilda Comet 147P/Kushida-Muramatsu: Another long temporary satellite capture by Jupiter |journal=Astronomy & Astrophysics |year=2008|volume=489|issue=3|page=1355|doi=10.1051/0004-6361:200810321|arxiv=0808.2277|bibcode=2008A&A...489.1355O|s2cid=14201751|url=http://www.arm.ac.uk/preprints/2008/531.pdf |archive-url=https://web.archive.org/web/20130226040659/http://www.arm.ac.uk/preprints/2008/531.pdf|url-status=dead |archive-date=2013-02-26 }}</ref>

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]],<ref>{{cite journal|url=http://adsabs.harvard.edu/abs/2010IJAsB...9....1H |title=Jupiter – friend or foe? III: the Oort cloud comets |first=J. |last=Horner |author2=Jones, B.W.; Chambers, J. |year=2010 |journal=International Journal of Astrobiology |volume=9 |number=1 |pages=1–10 |doi=10.1017/S1473550409990346 |arxiv=0911.4381 |bibcode=2010IJAsB...9....1H |s2cid=1103987 }}</ref> while it increases it in the case of asteroids<ref>{{cite journal |first=J. |last=Horner |author2=Jones, B.W. |title=Jupiter: Friend or foe? I: the asteroids |year=2008 |journal=International Journal of Astrobiology |volume=7 |number=3&4 |pages=251–261 |doi=10.1017/S1473550408004187 |arxiv=0806.2795 |bibcode=2008IJAsB...7..251H |s2cid=8870726 }}</ref> and short period comets.<ref>{{cite journal |first=J. |last=Horner |author2=Jones, B.W. |title=Jupiter – friend or foe? II: the Centaurs |year=2009 |journal=International Journal of Astrobiology |volume=8 |number=2 |pages=75–80 |doi=10.1017/S1473550408004357 |arxiv=0903.3305 |bibcode=2009IJAsB...8...75H |s2cid=8032181 |url=http://adsabs.harvard.edu/abs/2009IJAsB...8...75H }}</ref>

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.<ref name=Overbye>{{cite news |title=Jupiter: Our Cosmic Protector?|url=https://www.nytimes.com/2009/07/26/weekinreview/26overbye.html|author=Dennis Overbye|magazine=The New York Times|page=WK7|year=2009}}</ref> 2009 studies suggest an impact frequency of one every 50–350 years, for an object of 0.5–1&nbsp;km in diameter; impacts with smaller objects would occur more frequently. Another study estimated that comets {{convert|0.3|km|abbr=on}} in diameter impact the planet once in approximately 500 years and those {{convert|1.6|km|abbr=on}} in diameter do so just once in every 6,000 years.<ref>{{cite journal |last1=Roulston |first1=M.S. |date=March 1997 |title=Impact Mechanics and Frequency of SL9-Type Events on Jupiter |journal=[[Icarus (journal)|Icarus]] |volume=126 |issue=1 |pages=138–147 |doi=10.1006/icar.1996.5636 |last2=Ahrens |first2=T |bibcode=1997Icar..126..138R}}</ref>

In July 1994, [[Comet Shoemaker–Levy 9]] was a comet that broke apart and collided with Jupiter, providing the first direct observation of an extraterrestrial collision of Solar System objects.<ref name=NASA2005>{{cite web|url=http://nssdc.gsfc.nasa.gov/planetary/comet.html |title=Comet Shoemaker–Levy 9 Collision with Jupiter |access-date=2008-08-26 |publisher=[[National Space Science Data Center]] |date=February 2005}}</ref> The event 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.

The [[Jupiter 2009 impact event|2009 impact event]] happened on July 19 when a new black spot about the size of Earth was discovered in Jupiter's southern hemisphere by [[amateur astronomy|amateur astronomer]] [[Anthony Wesley]]. Thermal infrared analysis showed it was warm and spectroscopic methods detected ammonia. [[Jet Propulsion Laboratory|JPL]] scientists confirmed that there was another impact event on Jupiter, probably involving a small undiscovered comet or other icy body.<ref>{{cite news|url=http://www.cnn.com/2009/TECH/space/07/21/jupiter.nasa.meteor.scar/index.html|title=Mystery impact leaves Earth-sized mark on Jupiter|publisher=CNN | date=July 21, 2009}}</ref><ref>{{cite news|last=Overbye|first=Dennis|title=All Eyepieces on Jupiter After a Big Impact|url=https://www.nytimes.com/2009/07/22/science/space/22jupiter.html?hpw|newspaper=New York Times|date=July 22, 2009}}</ref><ref>[https://www.theguardian.com/science/2009/jul/21/jupiter-scar-comet-asteroid-crash Amateur astronomer spots Earth-size scar on Jupiter], Guardian, July 21, 2009</ref> The impactor is estimated to have been about 200–500 meters in diameter.

Later minor impacts were observed by amateur astronomers in 2010, 2012, 2016, and 2017; one impact was observed by ''[[Juno (spacecraft)|Juno]]'' in 2020.

====Other impacts====
{{See also|Impact events on Mars}}
[[File:Asteroid Collision Hubble.jpg|thumb|[[Hubble Space Telescope|Hubble]]'s [[Wide Field Camera 3]] clearly shows the slow evolution of the debris coming from asteroid [[P/2010 A2]], assumed to be due to a collision with a smaller asteroid.]]

In 1998, two comets were observed plunging toward 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 (unrelated to the impacts), can be found at the NASA<ref>{{cite web|url=https://sohowww.nascom.nasa.gov/hotshots/2000_02_07/|title=SOHO Hotshots|website=sohowww.nascom.nasa.gov|access-date=2019-01-23}}</ref> 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" [[C/1979 Q1|Howard-Koomen-Michels]], also known as Solwind 1, on August 30, 1979.<ref>{{cite web|url=http://home.earthlink.net/~tonyhoffman/SOHOfaq.htm#sunstrikers|title=A SOHO and Sungrazing Comet FAQ|website=home.earthlink.net|access-date=2019-01-23|archive-url=https://web.archive.org/web/20120805113942/http://home.earthlink.net/~tonyhoffman/SOHOfaq.htm#sunstrikers|archive-date=2012-08-05|url-status=dead}}{{self-published source|date=February 2017}}</ref>{{self-published inline|date=February 2017}} (See also [[sungrazer]].)

In 2010, between January and May, [[Hubble Space Telescope|Hubble]]'s Wide Field Camera 3<ref>[http://www.spacetelescope.org/news/heic1016/ Hubble finds that a bizarre X-shaped intruder is linked to an unseen asteroid collision] {{Webarchive|url=https://web.archive.org/web/20201127235555/http://www.spacetelescope.org/news/heic1016/ |date=2020-11-27 }}, www.spacetelescope.org October 13, 2010.</ref> took images of an unusual X shape originated in the aftermath of the collision between asteroid [[P/2010 A2]] with a smaller [[asteroid]].

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.<ref>{{cite web|url=https://mars.nasa.gov/news/nasa-mars-weathercam-helps-find-big-new-crater|title=NASA Mars Weathercam Helps Find Big New Crater|last=mars.nasa.gov|website=NASA's Mars Exploration Program|language=en|access-date=2019-01-23}}</ref>

On March 19, 2013, an impact occurred on the Moon that was visible from Earth, when a boulder-sized 30&nbsp;cm meteoroid slammed into the lunar surface at 90,000&nbsp;km/h (25&nbsp;km/s; 56,000&nbsp;mph) creating a 20-meter crater.<ref>{{cite web|url=https://blog.nationalgeographic.org/2013/05/17/nasa-announces-brightest-lunar-explosion-ever-recorded/|archive-url=https://web.archive.org/web/20181127131344/https://blog.nationalgeographic.org/2013/05/17/nasa-announces-brightest-lunar-explosion-ever-recorded/|url-status=dead|archive-date=November 27, 2018|title=NASA Announces Brightest Lunar Explosion Ever Recorded|date=2013-05-17|website=National Geographic Society Newsroom|language=en-US|access-date=2019-01-23}}</ref><ref>{{cite web|url=https://www.space.com/21259-moon-crash-meteor-impact-webcast.html|title=Moon Crash Scene Investigation Tonight: See Telescope Views of Meteorite Impact|last1=Kramer|first1=Miriam|last2=May 22|first2=Space com Staff Writer {{!}}|website=Space.com|access-date=2019-01-23|last3=ET|first3=2013 12:09pm|date=22 May 2013}}</ref> NASA has actively monitored lunar impacts since 2005,<ref>{{cite web|url=http://www.nasa.gov/centers/marshall/news/lunar/index.html|title=Lunar Impacts|last=Mohon|first=Lee|date=2017-02-13|website=NASA|access-date=2019-01-23|archive-date=2018-12-23|archive-url=https://web.archive.org/web/20181223031432/https://www.nasa.gov/centers/marshall/news/lunar/index.html|url-status=dead}}</ref> tracking hundreds of candidate events.<ref>{{Cite web|url=http://www.nasa.gov/centers/marshall/pdf/155422main_ALAMO_lunar_impact_observations294.pdf|title=NASA Marshall Space Flight Center (MSFC) – Automated Lunar and Meteor Observatory (ALaMO) – Candidate lunar impact observation database|access-date=2013-05-27|archive-date=2013-04-06|archive-url=https://web.archive.org/web/20130406093118/http://www.nasa.gov/centers/marshall/pdf/155422main_ALAMO_lunar_impact_observations294.pdf|url-status=dead}}</ref><ref>{{cite web|url=https://www.nasa.gov/centers/marshall/pdf/155422main_ALAMO_lunar_impact_observations294.pdf|title=List of lunar impact events|last=Marshall|first=Spaceflight Center|access-date=2019-01-23|archive-date=2020-08-01|archive-url=https://web.archive.org/web/20200801205744/https://www.nasa.gov/centers/marshall/pdf/155422main_ALAMO_lunar_impact_observations294.pdf|url-status=dead}}</ref>

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&nbsp;km (19 miles) from the impact site.<ref>{{Cite news |last=Amos |first=Jonathan |date=27 October 2022 |title=Nasa space probes document big impacts on Mars |language=en-GB |work=BBC News |url=https://www.bbc.com/news/science-environment-63418056 |access-date=28 October 2022 |archive-url=https://web.archive.org/web/20221028013508/https://www.bbc.com/news/science-environment-63418056 |archive-date=28 October 2022}}</ref>

=====Human caused impacts=====
[[File:DART-impact-SAAO-Lesedi-Mookodi.gif|thumb|right|Double Asteroid Redirection Test impact and its corresponding plume as seen by using the Mookodi instrument on the [[SAAO]]'s 1-m Lesedi telescope]]
In recent decades, human made probes have impacted either intentionally or unintentionally on several objects. Most of these probes were destroyed with little observable damage to their target. Some such probes on the Moon and Mars have left observable craters and debris. This includes landings such as the 1969 [[Apollo 11]] Moon Landing Site. High velocity crashes such as the 1972 [[Apollo 16]] S-IVB rocket,<ref name=":0">{{cite web|title=Apollo – Current Locations|url=http://nssdc.gsfc.nasa.gov/planetary/lunar/apolloloc.html|publisher=[[NASA]]|access-date=December 2, 2011}}</ref><ref>{{cite news|url=http://www.space.com/31503-apollo-16-moon-rocket-crash-site-photo.html|title=Moon Mystery Solved! Apollo Rocket Impact Site Finally Found|work=Space|first=Jesse|last=Emspak|publisher=[[Space.com]]|date=January 4, 2016|access-date=January 5, 2016}}</ref> 2019 [[Schiaparelli EDM]]<ref name="ReferenceC">{{cite web |url=http://www.esa.int/Our_Activities/Space_Science/ExoMars/Detailed_images_of_Schiaparelli_and_its_descent_hardware_on_Mars |title=Detailed images of Schiaparelli and its descent hardware on Mars |publisher=European Space Agency |date=27 October 2016 |access-date=4 November 2016}}</ref><ref>{{cite web |url=http://phys.org/news/2016-10-images-schiaparelli-descent-hardware-mars.html |title=Detailed images of Schiaparelli and its descent hardware on Mars |website=Phys.org |access-date=4 November 2016}}</ref> and 2023 [[Luna 25]]<ref>{{Cite web |last=Steigerwald |first=Bill |date=2023-08-30 |title=NASA's LRO Observes Crater Likely from Luna 25 Impact |url=http://www.nasa.gov/feature/goddard/2023/lro-luna-25-impact |access-date=2023-09-01 |website=NASA}}</ref> have also made physical changes to the landscape in the form of impact craters.

Specific missions designed to study effects including ejecta on target objects included 2005 [[Deep Impact (spacecraft)|Deep Impact]] mission on [[Tempel 1]] which caused an 100+ meter diameter crater,<ref name = "Stardust_prepares">{{Cite web
  | last = Lakdawalla
  | first = Emily
  | title = Stardust prepares for a first-second look at a comet: Tempel 1 on February 14
  | website = Planetary Society blog
  | publisher = [[The Planetary Society]]
  | date = 2011-01-19
  | url = http://www.planetary.org/blog/article/00002884/
  | access-date = 2011-02-19
  | archive-date = 2012-04-01
  | archive-url = https://web.archive.org/web/20120401234344/http://www.planetary.org/blog/article/00002884/
  | url-status = dead
  }}</ref> 2019 [[Hayabusa2]] mission on [[162173 Ryugu]], 2020 [[OSIRIS-REx]] mission on [[101955 Bennu]]<ref name="NYT-20181203">{{cite news|last=Chang|first=Kenneth|date=3 December 2018|title=NASA's Osiris-Rex Arrives at Asteroid Bennu After a Two-Year Journey|work=[[The New York Times]]|url=https://www.nytimes.com/2018/12/03/science/osiris-rex-bennu-asteroid-arrival.html|access-date=12 February 2021}}</ref> and 2022 [[Double Asteroid Redirection Test]] on [[Dimorphos]].<ref name="nasa-march2023">{{cite web |last1=Furfaro |first1=Emily |title=NASA's DART Data Validates Kinetic Impact as Planetary Defense Method |url=https://www.nasa.gov/feature/nasa-s-dart-data-validates-kinetic-impact-as-planetary-defense-method |website=NASA |access-date=9 March 2023 |date=28 February 2023}} {{PD-notice}}</ref><ref>{{cite journal |last1=Li |first1=Jian-Yang |last2=Hirabayashi |first2=Masatoshi |last3=Farnham |first3=Tony L. |last4=Sunshine |first4=Jessica M. |last5=Knight |first5=Matthew M. |last6=Tancredi |first6=Gonzalo |last7=Moreno |first7=Fernando |last8=Murphy |first8=Brian |last9=Opitom |first9=Cyrielle |last10=Chesley |first10=Steve |last11=Scheeres |first11=Daniel J. |last12=Thomas |first12=Cristina A. |last13=Fahnestock |first13=Eugene G. |last14=Cheng |first14=Andrew F. |last15=Dressel |first15=Linda |last16=Ernst |first16=Carolyn M. |last17=Ferrari |first17=Fabio |last18=Fitzsimmons |first18=Alan |last19=Ieva |first19=Simone |last20=Ivanovski |first20=Stavro L. |last21=Kareta |first21=Teddy |last22=Kolokolova |first22=Ludmilla |last23=Lister |first23=Tim |last24=Raducan |first24=Sabina D. |last25=Rivkin |first25=Andrew S. |last26=Rossi |first26=Alessandro |last27=Soldini |first27=Stefania |last28=Stickle |first28=Angela M. |last29=Vick |first29=Alison |last30=Vincent |first30=Jean-Baptiste |last31=Weaver |first31=Harold A. |last32=Bagnulo |first32=Stefano |last33=Bannister |first33=Michele T. |last34=Cambioni |first34=Saverio |last35=Bagatin |first35=Adriano Campo |last36=Chabot |first36=Nancy L. |last37=Cremonese |first37=Gabriele |last38=Daly |first38=R. Terik |last39=Dotto |first39=Elisabetta |last40=Glenar |first40=David A. |last41=Granvik |first41=Mikael |last42=Hasselmann |first42=Pedro H. |last43=Herreros |first43=Isabel |last44=Jacobson |first44=Seth |last45=Jutzi |first45=Martin |last46=Kohout |first46=Tomas |last47=La Forgia |first47=Fiorangela |last48=Lazzarin |first48=Monica |last49=Lin |first49=Zhong-Yi |last50=Lolachi |first50=Ramin |last51=Lucchetti |first51=Alice |last52=Makadia |first52=Rahil |last53=Epifani |first53=Elena Mazzotta |last54=Michel |first54=Patrick |last55=Migliorini |first55=Alessandra |last56=Moskovitz |first56=Nicholas A. |last57=Ormö |first57=Jens |last58=Pajola |first58=Maurizio |last59=Sánchez |first59=Paul |last60=Schwartz |first60=Stephen R. |last61=Snodgrass |first61=Colin |last62=Steckloff |first62=Jordan |last63=Stubbs |first63=Timothy J. |last64=Trigo-Rodríguez |first64=Josep M. |title=Ejecta from the DART-produced active asteroid Dimorphos |journal=Nature |date=1 March 2023 |volume=616 |issue=7957 |pages=452–456 |doi=10.1038/s41586-023-05811-4 |pmid=36858074 |pmc=10115637 |arxiv=2303.01700 |bibcode=2023Natur.616..452L |s2cid=257282549 |language=en |issn=1476-4687 |display-authors=3}}</ref> Observations show that Dimorphos lost approximately 1 million kilograms of mass and had its orbit changed as a result of the deliberate impact with the human made probe.<ref name="Lost 1M kg">{{cite journal |last1=Witze |first1=Alexandra |title=Asteroid lost 1 million kilograms as a result of the collision with DART spacecraft |journal=Nature |date=1 March 2023 |volume=615 |issue=7951 |pages=195 |doi=10.1038/d41586-023-00601-4 |pmid=36859675 |bibcode=2023Natur.615..195W |s2cid=257282080 |url=https://www.nature.com/articles/d41586-023-00601-4 |access-date=9 March 2023 |language=en}}</ref>