Editing Near-Earth object (section)

==== Highly rated risks ====
The National Aeronautics and Space Administration [[NASA]] maintains an automated system to evaluate the threat from known NEOs over the next 100 years, which generates the continuously updated [[Sentry Risk Table]].<ref name="Current_Impact_Risks" /> All or nearly all of the objects are highly likely to drop off the list eventually as more observations come in, reducing the uncertainties and enabling more accurate orbital predictions.<ref name="Current_Impact_Risks"/><ref name="2006HZ51">{{cite news |first=David |last=Chandler |title=Big new asteroid has slim chance of hitting Earth |date=May 2, 2006 |work=New Scientist |url=https://www.newscientist.com/article/dn9095-big-new-asteroid-has-slim-chance-of-hitting-earth |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20241226121230/https://www.newscientist.com/article/dn9095-big-new-asteroid-has-slim-chance-of-hitting-earth/ |archive-date=December 26, 2024}}</ref> When the close approach of a newly discovered asteroid is first put on a risk list with a significant risk, it is normal for the risk to first increase, regardless of whether the potential impact will eventually be ruled out or confirmed with the help of additional observations.<ref name="Smithsonian_no-panic">{{Cite news |first=Margherita |last=Bassi |title=Astronomers Raise Odds of Asteroid Impact in 2032 to 2.3 Percent—Here's Why You Shouldn't Panic |date=February 6, 2025 |work=[[Smithsonian (magazine)|Smithsonian]] |url=https://www.smithsonianmag.com/smart-news/astronomers-raise-odds-of-asteroid-impact-in-2032-to-2-3-percent-heres-why-you-shouldnt-panic-180985949/ |access-date=February 8, 2025 |url-status=live |archive-url=https://archive.today/20250208215442/https://www.smithsonianmag.com/smart-news/astronomers-raise-odds-of-asteroid-impact-in-2032-to-2-3-percent-heres-why-you-shouldnt-panic-180985949/ |archive-date=February 8, 2025}}</ref> Similar tables are maintained by the [[Near-Earth Object Coordination Centre]] (NEOCC) of the [[European Space Agency]] (ESA)<ref name="NEOCC-risk-list">{{cite web |title=Risk List |publisher=ESA NEOCC |url=https://neo.ssa.esa.int/risk-list |access-date=February 9, 2025 |url-status=live |archive-url=https://web.archive.org/web/20250207044752/https://neo.ssa.esa.int/risk-list |archive-date=February 7, 2025}}</ref> and on the [[NEODyS]] (Near Earth Objects Dynamic Site) by the [[University of Pisa]] spin-off company SpaceDyS.<ref>{{cite web |title=NEODyS-2 Risk List |website=NEODyS-2 |publisher=ESA |url=https://newton.spacedys.com/neodys/index.php?pc=4.1 |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20250102113021/https://newton.spacedys.com/neodys/index.php?pc=4.1 |archive-date=January 2, 2025}}</ref>

In March 2002, {{mpl|(163132) 2002 CU|11}} became the first asteroid with a temporarily positive rating on the Torino Scale, with about a 1 in 9,300 chance of an impact in 2049.<ref>{{cite news |first1=Andrea |last1=Milani |first2=Giovanni |last2=Valsecchi |first3=Maria Eugenia |last3=Sansaturio |title=The problem with 2002 CU11 |work=Tumbling Stone |volume=12 |publisher=[[NEODyS]] |date=March 12, 2002 |url=http://spaceguard.rm.iasf.cnr.it/tumblingstone/issues/num12/eng/2002cu11.htm |access-date=January 29, 2018 |url-status=dead |archive-url=https://web.archive.org/web/20160304023838/http://spaceguard.rm.iasf.cnr.it/tumblingstone/issues/num12/eng/2002cu11.htm |archive-date=March 4, 2016}}</ref> Additional observations reduced the estimated risk to zero, and the asteroid was removed from the Sentry Risk Table in April 2002.<ref name="removed">{{cite web |title=Date/Time Removed |date=December 31, 2024 |publisher=NASA/JPL CNEOS |url=https://cneos.jpl.nasa.gov/sentry/removed.html |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20250101175144/https://cneos.jpl.nasa.gov/sentry/removed.html |archive-date=January 1, 2025}}</ref> It is now known that within the next two centuries, {{mp|2002 CU|11}} will pass the Earth at a safe closest distance (perigee) of {{convert|0.00425|AU|km mi|abbr=on|lk=off}} on August 31, 2080.<ref>{{cite web |title=Small-Body Database Lookup. 163132 (2002 CU11) |date=June 6, 2022 |publisher=NASA/JPL |url=https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2002CU11&view=OPC |access-date=January 2, 2025}}</ref>

[[File:1950 DA (color).png|thumb|Radar image of asteroid {{mpl|29075|1950 DA}}]]
Asteroid {{mpl|29075|1950 DA}} has a diameter of about a kilometer (0.6 miles), and an impact would therefore be globally catastrophic. Although this asteroid will not strike for at least 800 years and thus has no Torino scale rating, it was added to the Sentry list in April 2002 as the first object with a Palermo scale value greater than zero.<ref name="IAU-NEOs"/><ref name="NEO-1950DA">{{cite web |title=29075 (1950 DA) Analyses, 2001-2007 |publisher=NASA/JPL CNEOS |url=http://cneos.jpl.nasa.gov/doc/1950da/ |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20241228030108/https://cneos.jpl.nasa.gov/doc/1950da/ |archive-date=December 28, 2024}}</ref> The then-calculated 1 in 300 maximum chance of impact and +0.17 Palermo scale value was roughly 50% greater than the background risk of impact by all similarly large objects until 2880.<ref name="NEO-1950DA"/><ref>{{cite journal |last1=Giorgini |first1=J. D. |last2=Ostro |first2=S. J. |last3=Benner |first3=L. A. M. |last4=Chodas |first4=P. W. |last5=Chesley |first5=S. R. |last6=Hudson |first6=R. S. |last7=Nolan |first7=M. C. |last8=Klemola |first8=A. R. |last9=Standish |first9=E. M. |last10=Jurgens |first10=R. F. |last11=Rose |first11=R |last12=Chamberlin |first12=A. B. |last13=Yeomans |first13=D. K. |last14=Margot |first14=J. L. |display-authors=2 |date=April 5, 2002 |title=Asteroid 1950 DA's Encounter with Earth in 2880: Physical Limits of Collision Probability Prediction |journal=Science |volume=296 |pages=132–136 |url=https://cneos.jpl.nasa.gov/doc/1950da/1950da_published.pdf |access-date=January 26, 2024 |url-status=live |archive-url=https://web.archive.org/web/20241222123826/https://cneos.jpl.nasa.gov/doc/1950da/1950da_published.pdf |archive-date=December 22, 2024 |doi=10.1126/science.1068191 |pmid=11935024 |issue=5565|bibcode = 2002Sci...296..132G |s2cid=8689246}}</ref> After additional radar<ref name=Farnocchia2013>{{Cite journal |last1=Farnocchia |first1=Davide |last2=Chesley |first2=Steven R. |title=Assessment of the 2880 impact threat from asteroid (29075) 1950 DA |date=2013 |journal=Icarus |volume=229 |pages=321–327 |arxiv=1310.0861 |doi=10.1016/j.icarus.2013.09.022 |bibcode=2014Icar..229..321F |s2cid=56453734}}</ref> and optical observations, {{As of|2025|3|lc=y}}, the probability of this impact is assessed at 1 in 2,600.<ref name="Current_Impact_Risks"/> The corresponding Palermo scale value of −0.92 is the second-highest for all objects on the Sentry List Table.<ref name="Current_Impact_Risks"/>

On December 24, 2004, five days after discovery, {{convert|370|m|ft|abbr=on}} asteroid [[99942 Apophis]] was assigned a 4 on the Torino scale, the highest rating given to date, as the information available at the time translated to a 1.6% chance of Earth impact in April 2029.<ref>{{cite news |first1=D. |last1=Yeomans |first2=S. |last2=Chesley |first3=P. |last3=Chodas |title=Near-Earth Asteroid 2004 MN4 Reaches Highest Score To Date On Hazard Scale |date=December 23, 2004 |publisher=NASA/JPL CNEOS |url=https://cneos.jpl.nasa.gov/news/news146.html |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20241231201857/https://cneos.jpl.nasa.gov/news/news146.html |archive-date=December 31, 2024}} <small>(Note: at the time the object was yet unnamed and was known only by its provisional designation {{mp|2004 MN|4}}.)</small></ref> As observations were collected over the next three days, the calculated chance of impact first increased to as high as 2.7%,<ref name="cneosnews164">{{cite news |first1=Dwayne |last1=Brown |first2=DC |last2=Agle |title=NASA Refines Asteroid Apophis' Path Toward Earth |date=October 7, 2009 |publisher=NASA/JPL CNEOS |url=https://cneos.jpl.nasa.gov/news/news164.html |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20241218203929/https://cneos.jpl.nasa.gov/news/news164.html |archive-date=December 18, 2024}}</ref> then fell back to zero, as the shrinking uncertainty zone for this close approach no longer included the Earth.<ref>{{cite news |first1=D. |last1=Yeomans |first2=S. |last2=Chesley |first3=P. |last3=Chodas |title=Possibility of an Earth Impact in 2029 Ruled Out for Asteroid 2004 MN4 |date=December 27, 2004 |publisher=NASA/JPL CNEOS |url=https://cneos.jpl.nasa.gov/news/news148.html |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20241230120623/https://cneos.jpl.nasa.gov/news/news148.html |archive-date=December 30, 2024}}</ref> There was at that time still some uncertainty about potential impacts during later close approaches. However, as the precision of orbital calculations improved due to additional observations, the risk of impact at any date was eliminated<ref>{{cite news |title=NASA Analysis: Earth Is Safe From Asteroid Apophis for 100-Plus Years |date=March 25, 2021 |work=News |publisher=NASA/JPL |url=https://www.jpl.nasa.gov/news/nasa-analysis-earth-is-safe-from-asteroid-apophis-for-100-plus-years |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20241212054436/https://www.jpl.nasa.gov/news/nasa-analysis-earth-is-safe-from-asteroid-apophis-for-100-plus-years/ |archive-date=December 12, 2024}}</ref> and Apophis was removed from the Sentry Risk Table in February 2021.<ref name="removed"/>

{{As of|2025|3}}, {{mpl|2010 RF|12}} was listed on the Sentry List Table with the highest chance of impacting Earth, at 1 in 10 on September 5, 2095.<ref name="Current_Impact_Risks"/> At only {{convert|7|m|ft|abbr=on}} across, the asteroid however is much too small to be considered a [[potentially hazardous asteroid]] and it poses no serious threat: the possible 2095 impact therefore rates only −2.97 on the Palermo Scale.<ref name="Current_Impact_Risks"/>

In January 2025, {{convert|55|m|ft|abbr=on}} asteroid {{mpl|2024 YR|4}} reached a 3 rating on the Torino scale for a possible impact on December 22, 2032, triggering an action plan to schedule observations with more powerful telescopes as the object recedes and gets dimmer, to determine its orbit with more precision and thus refine the impact risk prediction.<ref>{{cite news |first=Ian |last=Sample |title=Asteroid triggers global defence plan amid chance of collision with Earth in 2032 |date=January 30, 2025 |work=The Guardian |url=https://www.theguardian.com/science/2025/jan/30/asteroid-spotted-chance-colliding-with-earth-2032 |access-date=February 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20250202133421/https://www.theguardian.com/science/2025/jan/30/asteroid-spotted-chance-colliding-with-earth-2032 |archive-date=February 2, 2025}}</ref> In February 2025, the impact risk peaked at 1 in 32, then dropped below 1 in 1000 and the Torino scale rating was reduced to 0.<ref>{{cite news |first=Robert |last=Lea |title='That's impact probability zero folks!' Earth safe from 'city-killer' asteroid 2024 YR4 |date=February 24, 2025 |work=Space.com |url=https://www.space.com/the-universe/asteroids/earth-safe-from-city-killer-asteroid-2024-yr4-thats-impact-probability-zero-folks |access-date=March 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20250302170948/https://www.space.com/the-universe/asteroids/earth-safe-from-city-killer-asteroid-2024-yr4-thats-impact-probability-zero-folks |archive-date=March 2, 2025}}</ref> {{As of|2025|3|2}}, the impact risk for the 2032 encounter was down to 1 in 120,000.<ref name="Current_Impact_Risks"/>  By April, {{mp|2024 YR|4}} was on the other hand estimated to have a 4% chance of impacting a 70% [[Lunar phase#waninggibbous|waning gibbous moon]] on 22 December 2032<ref name="Helsinki"/> around 15:17 to 15:21&nbsp;UTC.<ref name="BillGray"/>