Editing Near-Earth object (section)

==== Asteroid deflection tests ====
[[File:DART-impact-SAAO-Lesedi-Mookodi.gif|thumb|Spread of the plume from the impact of the [[Double Asteroid Redirection Test|DART]] space probe on asteroid moon [[Dimorphos]] ([[SAAO]])]]

On September 26, 2022, NASA's ''[[Double Asteroid Redirection Test|DART]]'' spacecraft reached the system of {{mpl|65803 Didymos|}} and impacted the Apollo asteroid's moon [[Dimorphos]], in a test of a method of [[Asteroid impact avoidance|planetary defense]] against near-Earth objects.<ref name="NASA220927">{{cite news |first=Roxana |last=Bardan |title=NASA's DART Mission Hits Asteroid in First-Ever Planetary Defense Test |date=September 27, 2022 |work=Press Releases |publisher=NASA |url=https://www.nasa.gov/news-release/nasas-dart-mission-hits-asteroid-in-first-ever-planetary-defense-test/ |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20250101142705/https://www.nasa.gov/news-release/nasas-dart-mission-hits-asteroid-in-first-ever-planetary-defense-test/ |archive-date=January 1, 2025}}</ref> In addition to telescopes on or in orbit around the Earth, the impact was observed by the Italian mini-spacecraft or [[CubeSat]] ''LICIACube'', which separated from ''DART'' 15 days before impact.<ref name="NASA220927"/> The impact shortened the orbital period of Dimorphos around Didymos by 33 minutes, indicating that the moon's momentum change was 3.6 times the momentum of the impacting spacecraft, thus most of the change was due to the ejected material of the moon itself.<ref name="NASA221215">{{cite news |first=Jessica |last=Merzdorf |title=Early Results from NASA's DART Mission |date=December 15, 2022 |work=Press Releases |publisher=NASA |url=https://www.nasa.gov/solar-system/early-results-from-nasas-dart-mission/ |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20250102153424/https://www.nasa.gov/solar-system/early-results-from-nasas-dart-mission/ |archive-date=January 2, 2025}}</ref>

In October 2024, ESA launched the spacecraft ''[[Hera (space mission)|Hera]]'', which is to enter orbit around Didymos in December 2026, to study the consequences of the DART impact.<ref>{{cite web |title=Hera |publisher=ESA |url=https://www.esa.int/Space_Safety/Hera |access-date=December 31, 2024 |url-status=live |archive-url=https://web.archive.org/web/20241231085805/https://www.esa.int/Space_Safety/Hera |archive-date=December 31, 2024}}</ref> China plans to launch its own pair of asteroid deflection and observation probes in 2027, which are to target {{convert|30|m|ft|abbr=on}} Aten asteroid {{mpl|2015 XF|261}}.<ref>{{cite web |first1=Andrew |last1=Jones |title=China targets its first planetary defense test mission |date=July 2, 2024 |publisher=The Planetary Society |url=https://www.planetary.org/articles/china-targets-its-first-planetary-defense-test-mission |access-date=January 3, 2025 |url-status=live |archive-url=https://web.archive.org/web/20241008065834/https://www.planetary.org/articles/china-targets-its-first-planetary-defense-test-mission |archive-date=October 8, 2024}}</ref>