Editing Asteroid impact avoidance (section)

== Deflection efforts ==
[[File:Asteroids-KnownNearEarthObjects-Animation-UpTo20180101.gif|thumb|upright=1.5|Known [[Near-Earth objects]]{{Snd}} as of January 2018<br />[https://www.youtube.com/watch?v=vfvo-Ujb_qk Video (0:55; July 23, 2018)]<br />(Earth's orbit in white)]]
[[File:SmallAsteroidImpacts-Frequency-Bolide-20141114.jpg|thumb|upright=1.5|Frequency of small asteroids roughly 1 to 20 meters in diameter impacting Earth's atmosphere.]]

According to expert testimony in the [[United States Congress]] in 2013, [[NASA]] would require at least five years of preparation before a mission to intercept an asteroid could be launched.<ref name="US-Congress-20130410">{{cite web |author=U.S.Congress |title=Threats From Space: a Review of U.S. Government Efforts to Track and mitigate Asteroids and Meteors (Part I and Part II){{Snd}} Hearing Before the Committee on Science, Space, and Technology House of Representatives One Hundred Thirteenth Congress First Session |url=http://www.gpo.gov/fdsys/pkg/CHRG-113hhrg80552/pdf/CHRG-113hhrg80552.pdf |date=19 March 2013 |page=147 |work=[[United States Congress]] |access-date=3 May 2014 }}</ref> In June 2018, the US [[National Science and Technology Council]] warned that the United States was unprepared for an asteroid impact event, and developed and released the "National Near-Earth Object Preparedness Strategy Action Plan" to better prepare.<ref name="WH-20180621">{{cite web|url=https://trumpwhitehouse.archives.gov/wp-content/uploads/2018/06/National-Near-Earth-Object-Preparedness-Strategy-and-Action-Plan-23-pages-1MB.pdf|title=National Near-Earth Object Preparedness Strategy Action Plan|author=Staff|date=21 June 2018|via=[[NARA|National Archives]]|work=[[whitehouse.gov]]|access-date=22 June 2018}}</ref><ref name="GIZ-20180621">{{cite news|url=https://gizmodo.com/america-isnt-ready-to-handle-a-catastrophic-asteroid-im-1827014709|title=America Isn't Ready to Handle a Catastrophic Asteroid Impact, New Report Warns|last=Mandelbaum|first=Ryan F.|date=21 June 2018|work=[[Gizmodo]]|access-date=22 June 2018}}</ref><ref name="ICARUS-220180522">{{cite journal|last=Myhrvold|first=Nathan|author-link=Nathan Myhrvold|date=22 May 2018|title=An empirical examination of WISE/NEOWISE asteroid analysis and results|journal=[[Icarus (journal)|Icarus]]|volume=314|pages=64–97|bibcode=2018Icar..314...64M|doi=10.1016/j.icarus.2018.05.004|doi-access=free}}</ref><ref name="NYT-20180614">{{cite news|url=https://www.nytimes.com/2018/06/14/science/asteroids-nasa-nathan-myhrvold.html|title=Asteroids and Adversaries: Challenging What NASA Knows About Space Rocks|last=Chang|first=Kenneth|date=14 June 2018|work=[[The New York Times]]|access-date=22 June 2018}}</ref>

Most deflection efforts for a large object require from a year to decades of warning, allowing time to prepare and carry out a collision-avoidance project, as no known planetary defense hardware has yet been developed. It has been estimated that a velocity change of just {{nowrap|.035 m/s ÷ t}} (where t is the number of years until potential impact) is needed to successfully deflect a body on a direct collision trajectory. Thus for a large number of years before impact, much smaller velocity changes are needed.<ref name="ParkRoss">S.-Y. Park and [[I. Michael Ross|I. M. Ross]], "Two-Body Optimization for Deflecting Earth-Crossing Asteroids",  ''Journal of Guidance, Control and Dynamics'', Vol. 22, No. 3, 1999, pp.415–420.</ref> For example, it was estimated there was a high chance of [[99942 Apophis]] swinging by Earth in 2029 with a 10<sup>−4</sup> probability of returning on an impact trajectory in 2035 or 2036. It was then determined that a deflection from this potential return trajectory, several years before the swing-by, could be achieved with a velocity change on the order of 10<sup>−6</sup>&nbsp;m/s.<ref>Lu, Edward T. and Stanley G. Love. [https://web.archive.org/web/20160603070302/http://arxiv.org/abs/astro-ph/0509595 A Gravitational Tractor for Towing Asteroids], [[NASA]], Johnson Space Center, submitted to arxiv.org September 20, 2005. ([https://arxiv.org/abs/astro-ph/0509595 PDF document] {{webarchive |url=https://web.archive.org/web/20161005024351/http://arxiv.org/abs/astro-ph/0509595 |date=October 5, 2016 }}).</ref>

[[Double Asteroid Redirection Test|NASA's Double Asteroid Redirection Test]] (DART), the world's first full-scale mission to test technology for defending Earth against potential asteroid or comet hazards, launched on a SpaceX Falcon 9 rocket from Space Launch Complex 4 East at Vandenberg Space Force Base in California.<ref>{{Cite web |title=NASA, SpaceX Launch DART: First Planetary Defense Test Mission – Double Asteroid Redirection Test (DART) Mission |url=https://blogs.nasa.gov/dart/2021/11/24/nasa-spacex-launch-dart-first-planetary-defense-test-mission/ |access-date=2022-08-24 |website=blogs.nasa.gov |date=24 November 2021 |language=en-US}}</ref>

An impact by a {{convert|10|km|sigfig=1|adj=on|sp=us}} asteroid on the Earth has historically caused an [[extinction-level event]] due to catastrophic damage to the [[biosphere]]. There is also the threat from [[comet]]s entering the inner Solar System. The impact speed of a long-period comet would likely be several times greater than that of a [[near-Earth asteroid]], making its impact much more destructive; in addition, the warning time is unlikely to be more than a few months.<ref>{{cite web | url=http://www.nss.org/resources/library/planetarydefense/2000-ReportOfTheTaskForceOnPotentiallyHazardousNearEarthObjects-UK.pdf | title=Report of the Task Force on potentially hazardous Near Earth Objects | publisher=British National Space Center | access-date=2008-10-21 | archive-url=https://web.archive.org/web/20161210142717/http://nss.org/resources/library/planetarydefense/2000-ReportOfTheTaskForceOnPotentiallyHazardousNearEarthObjects-UK.pdf | archive-date=2016-12-10 | url-status=dead }}, p. 12.</ref> Impacts from objects as small as {{convert|50|m|sp=us}} in diameter, which are far more common, are historically extremely destructive regionally (see [[Barringer crater]]).

Finding out the material composition of the object is also helpful before deciding which strategy is appropriate. Missions like the 2005 ''[[Deep Impact (spacecraft)|Deep Impact]]'' probe and the [[Rosetta (spacecraft)|Rosetta]] spacecraft, have provided valuable information on what to expect. In October 2022, a method of mapping the insides of a potentially problematic asteroid in order to determine the best area for impact was proposed.<ref name="WP-20221021">{{cite news |last=Verma |first=Pranshu |title=There's a new tool to help blow up asteroids - Researchers from MIT and Stanford have created a tool that could improve the aim of future planetary defense missions |url=https://www.washingtonpost.com/technology/2022/10/21/asteroid-destruction-tool/ |date=21 October 2022 |newspaper=The Washington Post |accessdate=22 October 2022 }}</ref>

=== History of US government mandates ===

Efforts in [[asteroid impact prediction]] have concentrated on the survey method. The 1992 NASA-sponsored Near-Earth-Object Interception Workshop hosted by [[Los Alamos National Laboratory]] evaluated issues involved in intercepting celestial objects that could hit Earth.<ref>{{cite journal|last1=Canavan|first1=G. H.|last2=Solem|first2=J. C.|last3=Rather|first3=D. G.|year=1993|title=Proceedings of the Near-Earth-Object Interception Workshop, January 14–16, 1992, Los Alamos, NM|journal= Los Alamos National Laboratory LA—12476-C|url= https://ntrs.nasa.gov/search.jsp?R=19930019383}}</ref> In a 1992 report to [[NASA]],<ref name="morrison_1992">Morrison, D., 25 January 1992, [https://archive.org/details/nasa_techdoc_19920025001 ''The Spaceguard Survey: Report of the NASA International Near-Earth-Object Detection Workshop''] {{webarchive |url=https://web.archive.org/web/20161013041451/https://archive.org/details/nasa_techdoc_19920025001 |date=October 13, 2016 }}, [[NASA]], Washington, D.C.</ref> a coordinated [[Spaceguard]] Survey was recommended to discover, verify and provide follow-up observations for Earth-crossing asteroids. This survey was expected to discover 90% of these objects larger than one kilometer within 25 years. Three years later, another NASA report<ref>Shoemaker, E.M., 1995, ''Report of the Near-Earth Objects Survey Working Group'', NASA Office of Space Science, Solar System Exploration Office</ref> recommended search surveys that would discover 60–70% of short-period, near-Earth objects larger than one kilometer within ten years and obtain 90% completeness within five more years.

In 1998, NASA formally embraced the goal of finding and cataloging, by 2008, 90% of all near-Earth objects (NEOs) with diameters of 1&nbsp;km or larger that could represent a collision risk to Earth. The 1&nbsp;km diameter metric was chosen after considerable study indicated that an impact of an object smaller than 1&nbsp;km could cause significant local or regional damage but is unlikely to cause a worldwide catastrophe.<ref name="morrison_1992"/> The impact of an object much larger than 1&nbsp;km diameter could well result in worldwide damage up to, and potentially including, [[Human extinction|extinction of the human species]]. The NASA commitment has resulted in the funding of a number of NEO search efforts, which made considerable progress toward the 90% goal by 2008. However the 2009 discovery of several NEOs approximately 2 to 3 kilometers in diameter (e.g. {{mp|2009 CR|2}}, {{mp|2009 HC|82}}, {{mp|2009 KJ}}, {{mp|2009 MS}} and {{mp|2009 OG}}) demonstrated there were still large objects to be detected.

United States Representative [[George Brown Jr.|George E. Brown Jr.]] (D-CA) was quoted as voicing his support for planetary defense projects in ''Air & Space Power Chronicles'', saying "If some day in the future we discover well in advance that an asteroid that is big enough to cause a mass extinction is going to hit the Earth, and then we alter the course of that asteroid so that it does not hit us, it will be one of the most important accomplishments in all of human history."<ref>{{Cite journal|last=France|first=Martin|date=7 August 2000|title=Planetary Defense: Eliminating the Giggle Factor|url=https://www.airuniversity.af.edu/Portals/10/ASPJ/journals/Chronicles/france2.pdf|journal=Air & Space Power Chronicles|volume=14|pages=12|via=Air University}}</ref>

Because of Congressman Brown's long-standing commitment to planetary defense, a U.S. House of Representatives' bill, H.R. 1022, was named in his honor: The George E. Brown Jr. Near-Earth Object Survey Act. This bill "to provide for a Near-Earth Object Survey program to detect, track, catalogue, and characterize certain near-Earth asteroids and comets" was introduced in March 2005 by Rep. [[Dana Rohrabacher]] (R-CA).<ref>[[National Academy of Sciences]]. 2010. Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies: Final Report. Washington, DC: The National Academies Press. Available at: {{cite web|url=https://books.nap.edu/catalog.php?record_id%3D12842 |title=Browse All Topics {{pipe}} the National Academies Press |access-date=2016-10-02 |url-status=live |archive-url=https://web.archive.org/web/20140806153938/http://books.nap.edu/catalog.php?record_id=12842 |archive-date=2014-08-06 }}.</ref> It was eventually rolled into S.1281, the [[NASA Authorization Act of 2005]], passed by Congress on December 22, 2005, subsequently signed by the President, and stating in part:

{{blockquote|The U.S. Congress has declared that the general welfare and security of the United States require that the unique competence of NASA be directed to detecting, tracking, cataloguing, and characterizing near-Earth asteroids and comets in order to provide warning and mitigation of the potential hazard of such near-Earth objects to the Earth. The NASA Administrator shall plan, develop, and implement a Near-Earth Object Survey program to detect, track, catalogue, and characterize the physical characteristics of near- Earth objects equal to or greater than 140 meters in diameter in order to assess the threat of such near-Earth objects to the Earth. It shall be the goal of the Survey program to achieve 90% completion of its near-Earth object catalogue (based on statistically predicted populations of near-Earth objects) within 15 years after the date of enactment of this Act. The NASA Administrator shall transmit to Congress not later than 1 year after the date of enactment of this Act an initial report that provides the following: (A) An analysis of possible alternatives that NASA may employ to carry out the Survey program, including ground-based and space-based alternatives with technical descriptions. (B) A recommended option and proposed budget to carry out the Survey program pursuant to the recommended option. (C) Analysis of possible alternatives that NASA could employ to divert an object on a likely collision course with Earth.}}

The result of this directive was a report presented to Congress in early March 2007. This was an [[Analysis of Alternatives]] (AoA) study led by NASA's Program Analysis and Evaluation (PA&E) office with support from outside consultants, the Aerospace Corporation, NASA Langley Research Center (LaRC), and SAIC (amongst others).

See also [[Asteroid impact prediction#Improving impact prediction|Improving impact prediction]].

=== Ongoing projects ===
[[File:NEA by survey.png|thumb|Number of NEOs detected by various projects.]]
[[File:PIA22419-Neowise-1stFourYearsDataFromDec2013-20180420.gif|thumb|[[NEOWISE]]{{Snd}} first four years of data starting in December 2013 (animated; April 20, 2018)]]
The [[Minor Planet Center]] in [[Cambridge, Massachusetts]] has been cataloging the orbits of asteroids and comets since 1947. It has recently been joined by surveys that specialize in locating the [[near-Earth object]]s (NEO), many (as of early 2007) funded by NASA's Near Earth Object program office as part of their Spaceguard program. One of the best-known is [[LINEAR]] that began in 1996. By 2004 LINEAR was discovering tens of thousands of objects each year and accounting for 65% of all new asteroid detections.<ref>{{cite conference|first = G.|last = Stokes|author2 = J. Evans|date = 18–25 July 2004|title = Detection and discovery of near-Earth asteroids by the linear program|conference = 35th COSPAR Scientific Assembly|location = Paris, France|pages = 4338|bibcode =2004cosp...35.4338S}}</ref> LINEAR uses two one-meter telescopes and one half-meter telescope based in New Mexico.<ref>{{cite web|url = http://neo.jpl.nasa.gov/programs/linear.html|archive-url = https://web.archive.org/web/20040114170809/http://neo.jpl.nasa.gov/programs/linear.html|url-status = dead|archive-date = 14 January 2004|title = Lincoln Near-Earth Asteroid Research (LINEAR)|publisher = National Aeronautics and Space Administration|date = 23 October 2007}}</ref>

The [[Catalina Sky Survey]] (CSS) is conducted at the [[Steward Observatory]]'s [[Catalina Station]], located near [[Tucson, Arizona]], in the United States. It uses two telescopes, a {{convert|1.5|m|in|adj=on|sp=us}} f/2 telescope on the peak of [[Mount Lemmon]], and a {{convert|68|cm|in|adj=on|sp=us}} f/1.7 [[Schmidt camera|Schmidt]] telescope near [[Mount Bigelow (Arizona)|Mount Bigelow]] (both in the Tucson, Arizona area). In 2005, CSS became the most prolific NEO survey surpassing [[Lincoln Near-Earth Asteroid Research]] (LINEAR) in total number of NEOs and potentially hazardous asteroids discovered each year since. CSS discovered 310 NEOs in 2005, 396 in 2006, 466 in 2007, and in 2008 564 NEOs were found.<ref>[https://web.archive.org/web/20040513230213/http://neo.jpl.nasa.gov/stats/ NEO discovery statistics] from JPL. Shows the number of asteroids of various types (potentially hazardous, size > 1&nbsp;km, etc.) that different programs have discovered, by year.</ref>

[[Spacewatch]], which uses a {{convert|90|cm|in|adj=on|sp=us}} telescope sited at the [[Kitt Peak Observatory]] in Arizona, updated with automatic pointing, imaging, and analysis equipment to search the skies for intruders, was set up in 1980 by [[Tom Gehrels]] and [[Robert S. McMillan (astronomer)|Robert S. McMillan]] of the Lunar and Planetary Laboratory of the [[University of Arizona]] in Tucson, and is now being operated by McMillan. The Spacewatch project has acquired a {{convert|1.8|m|in|adj=on|sp=us}} telescope, also at Kitt Peak, to hunt for NEOs, and has provided the old 90-centimeter telescope with an improved electronic imaging system with much greater resolution, improving its search capability.<ref>{{cite web|url = http://spacewatch.lpl.arizona.edu/index.html|title = The Spacewatch Project|access-date = 2007-10-23|url-status = dead|archive-url = https://web.archive.org/web/20110211071733/http://spacewatch.lpl.arizona.edu/index.html|archive-date = 2011-02-11}}</ref>

Other near-Earth object tracking programs include [[Near-Earth Asteroid Tracking]] (NEAT), [[Lowell Observatory Near-Earth-Object Search]] (LONEOS), [[Campo Imperatore Near-Earth Object Survey]] (CINEOS), [[Japanese Spaceguard Association]], and [[Asiago-DLR Asteroid Survey]].<ref>{{cite web|url = http://neo.jpl.nasa.gov/programs/|archive-url = https://web.archive.org/web/20040114063231/http://neo.jpl.nasa.gov/programs/|url-status = dead|archive-date = 14 January 2004|title = Near-Earth Objects Search Program|publisher = National Aeronautics and Space Administration|date = 23 October 2007}}</ref> [[Pan-STARRS]] completed telescope construction in 2010, and it is now actively observing.

The [[Asteroid Terrestrial-impact Last Alert System]], now in operation, conducts frequent scans of the sky with a view to later-stage detection on the collision stretch of the asteroid orbit. Those would be much too late for deflection, but still in time for evacuation and preparation of the affected Earth region.

Another project, supported by the [[European Union]], is '''NEOShield''', which analyses realistic options for preventing the collision of a NEO with Earth. Their aim is to provide test mission designs for feasible NEO mitigation concepts. The project particularly emphasises on two aspects.<ref name=neoshield>{{cite journal |title=Science and Technology for Near-Earth Object Impact Prevention |doi=10.3030/640351 |url=https://cordis.europa.eu/project/id/640351 |journal=CORDIS |access-date=21 May 2023|url-access=subscription }}</ref>

# The first one is the focus on technological development on essential techniques and instruments needed for guidance, navigation and control (GNC) in close vicinity of asteroids and comets. This will, for example, allow hitting such bodies with a high-velocity kinetic impactor spacecraft and observing them before, during and after a mitigation attempt, e.g., for orbit determination and monitoring.
# The second one focuses on refining Near Earth Object (NEO) characterisation. Moreover, NEOShield-2 will carry out astronomical observations of NEOs, to improve the understanding of their physical properties, concentrating on the smaller sizes of most concern for mitigation purposes, and to identify further objects suitable for missions for physical characterisation and NEO deflection demonstration.<ref>{{cite web|url = http://www.neoshield.net/science-technology-asteroid-impact/|title = NEOShield Project|publisher = European Union Consortium|date = 17 November 2016|access-date = 17 November 2016|archive-date = 4 March 2017|archive-url = https://web.archive.org/web/20170304190851/http://www.neoshield.net/science-technology-asteroid-impact/|url-status = dead}}</ref>

"[[Spaceguard]]" is the name for these loosely affiliated programs, some of which receive NASA funding to meet a U.S. Congressional requirement to detect 90% of near-Earth asteroids over 1&nbsp;km diameter by 2008.<ref>{{cite web|url = http://neo.jpl.nasa.gov/neo/report.html|archive-url = https://web.archive.org/web/20031001091527/http://neo.jpl.nasa.gov/neo/report.html|url-status = dead|archive-date = 2003-10-01|title = NASA Releases Near-Earth Object Search Report|publisher = National Aeronautics and Space Administration|access-date = 2007-10-23}}</ref> A 2003 NASA study of a follow-on program suggests spending US$250–450 million to detect 90% of all near-Earth asteroids {{convert|140|m|ft|sp=us}} and larger by 2028.<ref>{{cite web|url = http://impact.arc.nasa.gov/news_detail.cfm?ID=168|title = NASA NEO Workshop|author = David Morrison|publisher = National Aeronautics and Space Administration|url-status = dead|archive-url = https://web.archive.org/web/20080122123731/http://impact.arc.nasa.gov/news_detail.cfm?ID=168|archive-date = 2008-01-22}}</ref>

In October 2013, the [[United Nations Committee on the Peaceful Uses of Outer Space]] approved several measures to deal with terrestrial asteroid impacts, including the creation of an [[International Asteroid Warning Network]] (IAWN) to act as a clearinghouse for shared information on dangerous asteroids and for any future terrestrial impact events that are identified. [[Space Missions Planning Advisory Group]] (SMPAG) should coordinate joint studies of the technologies for deflection missions, and as well provide oversight of actual missions. This is due to deflection missions typically involving a progressive movement of an asteroid's predicted impact point across the surface of the Earth (and also across the territories of uninvolved countries) until the NEO has been deflected either ahead of, or behind the planet at the point their orbits intersect.<ref name="New Scientist-2013.10.28">Aron, Jacob. [https://www.newscientist.com/article/dn24478-un-sets-up-asteroid-peacekeepers-to-defend-earth.html#.U999lGPCeKJ  UN Sets Up Asteroid Peacekeepers to Defend Earth], ''[[New Scientist]]'' website, October 28, 2013.  Retrieved August 4, 2014.</ref><ref name="LA Times-2013.10.28">Netburn, Deborah. [http://www.latimes.com/science/sciencenow/la-sci-sn-un-asteroid-defense-plan-20131028-story.html#axzz2j5WHIgR1 UN Aims to Fight Asteroids, Creates a Global Warning Network], ''[[Los Angeles Times]]'', October 28, 2013.  Retrieved August 4, 2014.</ref><ref name="New York Times-2013.11.06">Chang, Kenneth. [https://www.nytimes.com/2013/11/07/science/space/more-large-asteroid-strikes-are-likely-scientists-find.html More Asteroid Strikes Are Likely, Scientists Say],   ''[[The New York Times]]'' website, November 6, 2013, and in print on November 7, 2013, p. A12 of the New York edition. Retrieved June 26, 2014.</ref> [[UN General Assembly]] endorsed the establishment of IAWN through its resolution 68/75 on 16 December 2023.<ref>{{cite web|url = https://iawn.net/about.shtml |title = About IAWN|publisher = IAWN}}</ref> IAWN’s main task is to warn of a possible impact threat, if the following criteria are reached: an impact probability of >1% within the next 20 years, for an object larger than about 10 meters in size.<ref>{{cite web|url = https://www.nature.com/articles/s41467-024-48600-x |title =About the International Asteroid Warning Network (IAWN) and the Space Mission Planning Advisory Group (SMPAG) |publisher = Nature}}</ref>  The number of known NEOs was 34,274 as of 30 January 2024, with 2,395 known asteroids whose orbits bring them within 8 million kilometers of Earth’s orbit and with diameters larger than about 140 m. Yet, it is estimated only about 44% of the NEOs of that size range have been found so far.<ref>{{cite web|url =https://www.unoosa.org/documents/pdf/copuos/stsc/2024/Statements/10_IAWN.pdf  |title = Statement by IAWN Representative to STSC 61th session|publisher = UN Office for Outer Space Affairs}}</ref>

[[NEODyS]] is an online database of known NEOs.

==== Sentinel mission ====
{{Main|B612 Foundation|Sentinel Space Telescope}}

The [[B612 Foundation]] is a private nonprofit [[Private foundation (United States)|foundation]] with headquarters in the United States, dedicated to protecting the Earth from [[Impact event|asteroid strikes]]. It is led mainly by scientists, former astronauts and engineers from the [[Institute for Advanced Study]], [[Southwest Research Institute]], [[Stanford University]], [[NASA]] and the [[space industry]].

As a non-governmental organization it has conducted two lines of related research to help detect NEOs that could one day strike the Earth, and find the technological means to divert their path to avoid such collisions. The foundation's goal had been to design and build a privately financed asteroid-finding [[Space observatory|space telescope]], [[Sentinel (space telescope)|Sentinel]], which was to be launched in 2017–2018. However the project was cancelled in 2015. Had the Sentinel's infrared telescope been parked in an orbit similar to that of [[Venus]], it would have helped identify threatening NEOs by cataloging 90% of those with diameters larger than {{convert|140|m|sp=us}}, as well as surveying smaller Solar System objects.<ref name="Discover-2013.09">Powell, Corey S. [http://discovermagazine.com/2013/september/17-hunting-season-for-asteroids "Developing Early Warning Systems for Killer Asteroids"] {{webarchive |url=https://web.archive.org/web/20161028014849/http://discovermagazine.com/2013/september/17-hunting-season-for-asteroids |date=October 28, 2016 }}, ''[[Discover (magazine)|Discover]]'', August 14, 2013, pp. 60–61 (subscription required).</ref><ref name="B612-Sentinel Mission" /><ref name="New York Times-2013.02.16" />

Data gathered by Sentinel would have helped identify [[asteroid]]s and other NEOs that pose a risk of collision with Earth, by being forwarded to scientific data-sharing networks, including [[NASA]] and academic institutions such as the Minor Planet Center.<ref name="B612-Sentinel Mission">{{cite web|title=The Sentinel Mission |publisher=B612 Foundation |url=http://b612foundation.org/media/sentinelmission/ |access-date=September 19, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120910234035/http://b612foundation.org/media/sentinelmission/ |archive-date=September 10, 2012 }}</ref><ref name="New York Times-2013.02.16">Broad, William J. [https://www.nytimes.com/2013/02/17/science/space/dismissed-as-doomsayers-advocates-for-meteor-detection-feel-vindicated.html Vindication for Entrepreneurs Watching Sky: Yes, It Can Fall] {{webarchive |url=https://web.archive.org/web/20141104050747/http://www.nytimes.com/2013/02/17/science/space/dismissed-as-doomsayers-advocates-for-meteor-detection-feel-vindicated.html |date=November 4, 2014 }}, ''[[The New York Times]]'' website, February 16, 2013 and in print on February 17, 2013, p. A1 of the New York edition. Retrieved June 27, 2014.</ref><ref name="Space.com-2012.07.10">{{cite web| first=Mike | last=Wall| title=Private Space Telescope Project Could Boost Asteroid Mining| work=[[Space.com]]| date=July 10, 2012 | access-date=September 14, 2012| url=http://www.space.com/16501-private-space-telescope-asteroid-mining.html}}</ref> The foundation also proposes asteroid deflection of potentially dangerous NEOs by the use of [[gravity tractor]]s to divert their trajectories away from Earth,<ref name="Discover-2013.10">Powell, Corey S. [http://discovermagazine.com/2013/oct/16-how-to-dodge-a-cosmic-bullet How to Deflect a Killer Asteroid: Researchers Come Up With Contingency Plans That Could Help Our Planet Dodge A Cosmic Bullet] {{webarchive |url=https://web.archive.org/web/20160828054622/http://discovermagazine.com/2013/oct/16-how-to-dodge-a-cosmic-bullet |date=August 28, 2016 }},  ''[[Discover (magazine)|Discover]]'' website, September 18, 2013  (subscription required), and in print as "How to Dodge a Cosmic Bullet", October 2013. Retrieved July 15, 2014.</ref><ref name="B612-2002">{{cite web|title=PROJECT B612: Deflecting an Asteroid using Nuclear-Powered Plasma Drive Propulsion (home page) |publisher=Project B612 (now B612 Foundation) |date=November 26, 2002 |url=http://b612.boulder.swri.edu/ |access-date=April 15, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20110712085255/http://b612.boulder.swri.edu/ |archive-date=July 12, 2011 }}</ref> a concept co-invented by the organization's CEO, physicist and former NASA astronaut [[Ed Lu]].<ref name="Nature-Vol. 438 No. 7065-Lu, Love">{{cite journal | last1 = Lu | first1 = Edward T. | last2 = Love | first2 = Stanley G. | year = 2005 | title = Gravitational Tractor For Towing Asteroids | journal = Nature | volume = 438 | issue = 7065| pages = 177–178 | doi = 10.1038/438177a | pmid = 16281025 | arxiv = astro-ph/0509595 |bibcode = 2005Natur.438..177L | s2cid = 4414357 }}</ref>

=== Prospective projects ===
[[Orbit@home]] intends to provide distributed computing resources to optimize search strategy. On February 16, 2013, the project was halted due to lack of grant funding.<ref>{{cite web|url=http://orbit.psi.edu/?q=node/32|title=Project Stopped|website=Orbit.psi.edu|access-date=2013-10-29|url-status=dead|archive-url=https://web.archive.org/web/20130802060805/http://orbit.psi.edu/?q=node%2F32|archive-date=2013-08-02}}</ref> However, on July 23, 2013, the orbit@home project was selected for funding by NASA's Near Earth Object Observation program and was to resume operations sometime in early 2014.<ref>{{cite web|url=http://orbit.psi.edu/?q=node/32|title=orbit@home is upgrading!|website=Orbit.psi.edu|access-date=2013-10-29|url-status=dead|archive-url=https://web.archive.org/web/20140227092309/http://orbit.psi.edu/?q=node%2F32|archive-date=2014-02-27}}</ref> As of July 13, 2018, the project is offline according to its website.<ref>{{cite web|url=http://orbit.psi.edu/?q=node/33|title=The orbit@home project is currently offline|website=Orbit.psi.edu|access-date=2018-07-13|url-status=live|archive-url=https://web.archive.org/web/20180713232632/http://orbit.psi.edu/?q=node%2F33|archive-date=2018-07-13}}</ref>

The [[Large Synoptic Survey Telescope]], currently under construction, is expected to perform a comprehensive, high-resolution survey starting in the early 2020s.<ref>{{cite conference |last1=Jones |first1=R. Lynne |last2=Juric |first2=Mario |last3=Ivezic |first3=Zeljko |date=10 November 2015 |title=Asteroid Discovery and Characterization with the Large Synoptic Survey Telescope (LSST) |conference=IAU-318 – Asteroids: New Observations, New Models |arxiv=1511.03199}}</ref>

===Detection from space===
On November 8, 2007, the [[House Committee on Science and Technology]]'s [[United States House Science Subcommittee on Space|Subcommittee on Space]] and Aeronautics held a hearing to examine the status of NASA's Near-Earth Object survey program. The prospect of using the [[Wide-field Infrared Survey Explorer]] was proposed by NASA officials.<ref>{{Cite web|url=http://www.spaceref.ca/news/viewsr.html?pid=25960|title=Hearing Charter: Near-Earth Objects: Status of the Survey Program and Review of NASA's 2007 Report to Congress {{pipe}} SpaceRef Canada – Your Daily Source of Canadian Space News<!-- Bot generated title -->|access-date=2021-02-27|archive-date=2012-12-05|archive-url=https://archive.today/20121205230352/http://www.spaceref.ca/news/viewsr.html?pid=25960|url-status=dead}}</ref>

WISE surveyed the sky in the infrared band at a very high sensitivity. Asteroids that absorb solar radiation can be observed through the infrared band. It was used to detect NEOs, in addition to performing its science goals. It is projected that WISE could detect 400 NEOs (roughly two percent of the estimated NEO population of interest) within the one-year mission.

[[Near Earth Object Surveillance Satellite|NEOSSat]], the Near Earth Object Surveillance Satellite, is a [[microsatellite]] launched in February 2013 by the [[Canadian Space Agency]] (CSA) that will hunt for NEOs in space.<ref name="Hildebrand2008">{{cite conference |url=http://www.lpi.usra.edu/meetings/acm2008/pdf/8293.pdf |title=The Near Earth Object Surveillance Satellite (NEOSSat) Mission Will Conduct an Efficient Space-Based Asteroid Survey at Low Solar Elongations |conference=Asteroids, Comets, Meteors |first1=A. R. |last1=Hildebrand |first2=E. F. |last2=Tedesco |first3=K. A. |last3=Carroll |year=2008 |id=Paper id 8293 |bibcode=2008LPICo1405.8293H|display-authors=etal}}</ref><ref name="CalHerald20080502">{{cite news|url=http://www.canada.com/topics/news/world/story.html?id=278ed690-ccf5-4bdd-88ee-ce83eecb2db4&k=41066 |title=Canada space mission targets asteroids |work=[[Calgary Herald]] via Canada.com |first=Tom |last=Spears |date=May 2, 2008 |access-date=June 27, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20121106103756/http://www.canada.com/topics/news/world/story.html?id=278ed690-ccf5-4bdd-88ee-ce83eecb2db4&k=41066 |archive-date=November 6, 2012 }}</ref> Furthermore [[NEOWISE|Near-Earth Object WISE (NEOWISE)]], an extension of the [[Wide-field Infrared Survey Explorer|WISE]] mission, started in September 2013 (in its second mission extension) to hunt [[asteroid]]s and [[comet]]s [[Near-Earth object|close to the orbit of Earth]].<ref name="nasa20130821">{{cite web |url=http://www.jpl.nasa.gov/wise/newsfeatures.cfm?release=2013-257 |title=NASA Spacecraft Reactivated to Hunt for Asteroids |publisher=[[NASA]] |first1=D. C. |last1=Agle |first2=Dwayne |last2=Brown |date=August 21, 2013 |access-date=April 24, 2018 |archive-date=August 30, 2013 |archive-url=https://web.archive.org/web/20130830000959/http://www.jpl.nasa.gov/wise/newsfeatures.cfm?release=2013-257 |url-status=dead }}</ref><ref>{{cite web |url=https://hackaday.com/2020/07/22/the-wise-in-neowise-how-a-hibernating-satellite-awoke-to-discover-the-comet/ |title=The WISE In NEOWISE: How A Hibernating Satellite Awoke To Discover The Comet |date=July 22, 2020 |first=Tom |last=Nardi}}</ref>

=== ''Deep Impact'' ===

Research published in the March 26, 2009 issue of the journal ''[[Nature (journal)|Nature]]'', describes how scientists were able to identify an asteroid in space before it entered Earth's atmosphere, enabling computers to determine its area of origin in the Solar System as well as predict the arrival time and location on Earth of its shattered surviving parts. The four-meter-diameter asteroid, called [[2008 TC3|2008 TC<sub>3</sub>]], was initially sighted by the automated [[Catalina Sky Survey]] telescope, on October 6, 2008. Computations correctly predicted that it would impact 19 hours after discovery and in the [[Nubian Desert]] of northern Sudan.<ref>{{cite web |url=https://www.newswise.com/articles/we-saw-it-coming-asteroid-monitored-from-outer-space-to-ground-impact |title=We Saw It Coming: Asteroid Monitored from Outer Space to Ground Impact |archive-url=https://web.archive.org/web/20160303201008/http://newswise.com/articles/view/550468/ |archive-date=March 3, 2016 |url-status=live |work=Newswise |access-date=March 26, 2009}}</ref>

A number of potential threats have been identified, such as [[99942 Apophis]] (previously known by its [[provisional designation]] {{mp|2004&nbsp;MN|4}}), which in 2004 temporarily had an impact probability of about 3% for the year 2029. Additional observations revised this probability down to zero.<ref>{{cite web |url=http://neo.jpl.nasa.gov/apophis/ |archive-url=https://web.archive.org/web/20071027032753/http://neo.jpl.nasa.gov/apophis/ |url-status=dead |archive-date=2007-10-27 |title=99942 Apophis (2004 MN4): Predicting Apophis' Earth Encounters in 2029 and 2036}}</ref>

=== ''Double Asteroid Redirection Test'' ===

On September 26, 2022 [[Double Asteroid Redirection Test|DART]] impacted [[Dimorphos]], reducing the minor-planet moon's orbital period by 32 minutes. This mission was the [[Timeline of space exploration|first successful attempt]] at asteroid deflection.<ref name=":2" />

=== 2019 VL5 Asteroid Deflection Mission ===

In 2025, China's [[CNSA]] intends to launch a deflection mission to near-Earth object [[2019 VL5]], a 30-meter wide asteroid. The mission will launch on a [[Long March 3B]] rocket and carry both an impactor and observer spacecraft.<ref name=":3" /><ref name=":4">{{Cite web |last=Andrew Jones published |date=2022-12-08 |title=China will launch 2-in-1 asteroid deflection mission in 2025 |url=https://www.space.com/china-asteroid-impact-mission-two-spacecraft |access-date=2023-04-17 |website=Space.com |language=en}}</ref><ref>{{Cite web |last=Young |first=Chris |date=2023-04-12 |title=China will launch an impactor spacecraft to alter asteroid trajectory |url=https://interestingengineering.com/science/china-to-alter-asteroid-trajectory |access-date=2023-04-17 |website=interestingengineering.com |language=en-US}}</ref>