{{Short description|Near-Earth asteroid}} {{Use dmy dates|date=March 2023}} {{DISPLAYTITLE:{{mp|2023 GQ|2}}}} {{Infobox planet | minorplanet = yes | name = {{mp|2023 GQ|2}} | background = #FFC2E0 | discovery_ref = <ref name="MPC-object" /> | discovered = 12 April 2023 | discovery_site = [[Bok Telescope]] @ [[Kitt Peak National Observatory]] | mpc_name = {{mp|2023 GQ|2}} | mp_category = {{Hlist | [[Near-Earth object|NEO]] | [[Potentially hazardous object|PHA]] | [[List of Apollo asteroids|Apollo]] }} | orbit_ref = <ref name="jpldata" /> | epoch = 25 February 2023 ([[Julian day|JD]] 2460000.5) | uncertainty = 3 | observation_arc = 3.93 years | earliest_precovery_date = 13 May 2019 | aphelion = {{val|2.305|ul=AU}} | perihelion = {{val|0.9837|u=AU}} | time_periastron = 2022-Jul-12 | semimajor = {{val|1.6444|u=AU}} | eccentricity = {{val|0.4017}} | period = {{val|2.11}} [[Julian year (astronomy)|yr]]<br/>({{val|770.17}} days) | mean_anomaly = {{val|106.38|ul=°}} | inclination = {{val|36.84|u=°}} | asc_node = {{val|53.83|u=°}} | arg_peri = {{val|349.34|u=°}} | moid = {{Convert|0.0012|AU|e3km LD|abbr=unit}} | dimensions = {{Ubl | 290–650 meters | ≈{{convert|400|m|sigfig=2|abbr=on}}<ref name="Sentry"/> }} | abs_magnitude = {{val|19.8|0.3|u=mag}}<ref name="jpldata" /> | magnitude = }}
'''{{mp|2023 GQ|2}}''' is an [[asteroid]] roughly 400 meters in diameter, classified as a [[near-Earth object]] and [[potentially hazardous object]] of the [[Apollo asteroid|Apollo group]]. It was first discovered on 12 April 2023, when it was {{Convert|1.3|AU|e6km|abbr=unit|lk=on}} from Earth, with the [[Bok Telescope]] at [[Kitt Peak National Observatory]].<ref name="MPC-object" /> On 19 April 2023, with an [[observation arc]] of 6.7 days, it was rated 1 on the [[Torino scale]] for a [[Sentry (monitoring system)|virtual impactor]] on 16 November 2028 at 00:58 [[Coordinated Universal Time|UTC]].<ref name="Sentry7" /> When it had a [[Palermo scale]] rating of –0.70,<ref name="Sentry7"/> the odds of impact were about 5 times less than the background hazard level and this gave the asteroid one of the highest Palermo scale ratings ever issued. On 20 April 2023 [[precovery]] images from May 2019 were announced extending the observation arc to 3.9 years,<ref name="MPC-object" /> and the 2028 virtual impactor was removed from the [[Sentry Risk Table]].<ref name=Sentry/> It is now known the [[Curve fitting|nominal]] approach will safely occur about 13 hours after the impact scenario on 16 November 2028 13:36 ± 40 minutes.<ref name="jpldata"/>
The asteroid will come to [[aphelion]] (farthest distance from the Sun) around 1 August 2023.<ref name="Aphelion"/>
== 2028 == With a short 6.7 day observation arc, virtual clones of the asteroid that fit the uncertainty region in the known trajectory showed a 1-in-24,000 chance that the asteroid could [[Impact event|impact]] Earth on 16 November 2028 00:58 UT.<ref name="Sentry7"/> With precovery images and a 3.9 year observation arc, the [[Curve fitting|nominal]] approach (line of variation) has the asteroid {{Convert|0.012|AU|e6km|abbr=unit|lk=on}} {{Nowrap|± 94 thousand km}} from Earth at the time of the potential impact on 16 November 2028.<ref name=Horizons2028/> The [[Curve fitting|nominal]] closest approach will occur about 13 hours after the impact scenario on 16 November 2028 13:36 ± 40 minutes.<ref name="jpldata"/>
{| class="wikitable sortable" style="text-align:center; font-size: 0.9em;" |+{{mp|2023 GQ|2}} [[Curve fitting|nominal]] approach for 16 November 2028 00:58 virtual impactor ! Solution ! [[Observation arc|Observation<br/>arc]]<br/>(in days) ! [[JPL Horizons]]<br />[[Curve fitting|nominal]] geocentric<br />distance ([[astronomical unit|AU]]) ! uncertainty<br />region<br />([[3-sigma]]) ! Impact<br />probability ! [[Torino Scale|Torino<br/>scale]] ! [[Palermo scale|Palermo<br/>scale]]<br/>(max) |- |JPL #1 [https://web.archive.org/web/20230417192026/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272023+GQ2%27&START_TIME=%272028-11-16%2000:58%27&STOP_TIME=%272028-11-17%27&STEP_SIZE=%272%20day%27&QUANTITIES=%2720,39%27 (2023-Apr-17)] || 5 (26 obs) || {{Convert|0.0085|AU|e6km|abbr=unit|lk=on}} || {{Nowrap|± 90 million km}} || 1:560000<ref name=Sentry5/> || 0 || –2.08 |- |JPL #3 [https://web.archive.org/web/20230419200629/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272023+GQ2%27&START_TIME=%272028-11-16%2000:58%27&STOP_TIME=%272028-11-17%27&STEP_SIZE=%272%20day%27&QUANTITIES=%2720,39%27 (2023-Apr-19)] || 7 (29 obs) || {{Convert|0.0053|AU|e6km|abbr=unit}} || {{Nowrap|± 16 million km}} || 1:24000<ref name="Sentry7"/> || 1 || –0.70 |- |JPL #4 [https://web.archive.org/web/20230420144523/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272023+GQ2%27&START_TIME=%272028-11-16%2000:58%27&STOP_TIME=%272028-11-17%27&STEP_SIZE=%272%20day%27&QUANTITIES=%2720,39%27 (2023-Apr-20)] || 1437 (35 obs) || {{Convert|0.0121|AU|e6km|abbr=unit}} || {{Nowrap|± 0.094 million km}} || none<ref name="Sentry"/> || N/A || N/A |}
{{anchor|2028CA}} {| class="wikitable" style="text-align:center; font-size: 0.9em;" |+{{mp|2023 GQ|2}} Earth approach on 16 November 2028<br/>(about 13 hours after the impact scenario) ! Date & time ! [[Curve fitting|Nominal]] distance ! uncertainty<br />region<br />([[3-sigma]]) |- |2028-Nov-16 13:36 ± 40 minutes || {{val|1522786|u=km}}<ref name=jpldata/> || {{Nowrap|± 80 thousand km}}<ref name=Horizons2028CA/> |}
== References == <references>
<ref name="jpldata">{{cite web |type=2023-04-19 last obs. |title=JPL Small-Body Database Browser: (2023 GQ2) |url=https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2023%20GQ2&view=OPC |publisher=[[Jet Propulsion Laboratory]] |archive-url=https://archive.today/20230419190151/https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html%23/?sstr=2023%20GQ2&view=OPC |archive-date=2023-04-19 |url-status=live |accessdate=2023-04-20}}</ref>
<ref name="MPC-object">{{cite web |title=2023 GQ2 Orbit |work=Minor Planet Center |url=https://www.minorplanetcenter.net/db_search/show_object?object_id=2023+GQ2 |accessdate=2023-04-20}}</ref>
<ref name="Sentry">{{cite web |title=Sentry Risk Table: 2023 GQ2 |publisher=NASA JPL [[Center for Near-Earth Object Studies|CNEOS]] |url=https://cneos.jpl.nasa.gov/sentry/details.html#?des=2023%20GQ2 |archive-url=https://archive.today/20230417191312/https://cneos.jpl.nasa.gov/sentry/details.html%23?des=2023%20GQ2 |archive-date=2023-04-17 |url-status=live }}</ref>
<ref name="Sentry5">{{cite web |title=Archive of Sentry Risk Table: 2023 GQ2 (4.9 day arc) |publisher=NASA JPL [[Center for Near-Earth Object Studies|CNEOS]] |url=https://archive.today/20230417191312/https://cneos.jpl.nasa.gov/sentry/details.html%23?des=2023%20GQ2 }}</ref>
<ref name="Sentry7">{{cite web |title=Archive of Sentry Risk Table: 2023 GQ2 (6.7 day arc) |publisher=NASA JPL [[Center for Near-Earth Object Studies|CNEOS]] |url=https://archive.today/20230419182431/https://cneos.jpl.nasa.gov/sentry/details.html%23?des=2023%20GQ2 }}</ref>
<ref name="Aphelion">{{cite web |title=Aphelion around 1 August 2023 |publisher=[[JPL Horizons On-Line Ephemeris System|JPL Horizons]] |type=Aphelion occurs when rdot flips from positive to negative |url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272023+GQ2%27&START_TIME=%272023-07-29%27&STOP_TIME=%272023-08-04%27&STEP_SIZE=%276%20hour%27&QUANTITIES=%2719%27 |accessdate=2023-04-20}}</ref>
<ref name="Horizons2028">{{cite web |title=JPL Horizons: 2023 GQ2 geocentric distance and uncertainty on 16 November 2028 VI |publisher=JPL Horizons |url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272023+GQ2%27&START_TIME=%272028-11-16%2000:58%27&STOP_TIME=%272028-11-17%27&STEP_SIZE=%272%20day%27&QUANTITIES=%2720,39%27 |accessdate=2023-04-20}}</ref>
<ref name=Horizons2028CA>{{cite web |title=JPL Horizons: 2023 GQ2 geocentric distance and uncertainty on 16 Nov 2028 close approach |publisher=JPL Horizons |url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272023+GQ2%27&START_TIME=%272028-11-16%2013:36%27&STOP_TIME=%272028-11-17%27&STEP_SIZE=%272%20day%27&QUANTITIES=%2720,39%27 |accessdate=2023-04-20}}</ref>
</references> <!-- end of reflist -->
== External links == * {{NeoDys|2023+GQ2}} * {{ESA-SSA|2023GQ2}} * {{JPL small body|id=54354410}}
{{2023 in space}} {{Small Solar System bodies}} {{Authority control}}
{{DEFAULTSORT:2023 GQ2}} [[Category:Apollo asteroids|#]] [[Category:Minor planet object articles (unnumbered)]] [[Category:Near-Earth objects removed from the Sentry Risk Table]] [[Category:Astronomical objects discovered in 2023|20230412]]