View source for 2022 NX1

{{Short description|Temporary satellite capture}}
{{DISPLAYTITLE:{{mp|2022 NX|1}}}}
{{Use dmy dates|date=July 2022}}
{{Infobox planet
| minorplanet = yes
| background = #FFC2E0
| name = {{mp|2022 NX|1}}
| discovery_ref = <ref name="MPEC2022-O04"/>
| discoverer = Moonbase South Observatory 
| discovered = 2 July 2022
| mpc_name = {{mp|2022 NX|1}}
| alt_names = xkos033
| mp_category = {{Hlist
 | Artificial?<ref name="MPEC2022-O04"/>
 | [[Near-Earth object|NEO]]
 | [[Apollo asteroid|Apollo]]
 | [[Sentry (monitoring system)|risk listed]]<ref name=sentry/>
 }}
| orbit_ref = <ref name="jpldata"/>
| epoch = 2023-Feb-25 ([[Julian day|JD]]&nbsp;2460000.5)
| uncertainty = 1
| observation_arc = 142 days
| moid = {{Convert|0.0120258|AU|km LD|abbr=on}} 
| jupiter_moid = {{Convert|3.93788|AU|km|abbr=on}}
| aphelion = {{val|1.04749104|ul=AU}} (Q)
| perihelion = {{val|0.99635808|u=AU}} (q)
| time_periastron = 2022-Dec-18.7784<ref name="perihelion"/>
| semimajor = {{val|1.02192456|u=AU}} (a)
| eccentricity = {{val|0.02501797}} (e)<br />(Geocentric [[Hyperbolic trajectory|hyperbolic]] e=1.1)<ref name="geocentric"/>
| period = {{val|1.03308595|u=years}}
| inclination = {{val|1.066697|u=°}} (i)
| asc_node = {{val|274.76734|u=°}} (Ω)
| mean_anomaly = {{val|65.0876|ul=°}} (M)
| arg_peri = {{val|169.58306|u=°}} (ω)
| dimensions = {{Ubl
 | ~{{convert|9|m|sigfig=2|abbr=on}}<ref name=sentry/>
 | 7–14 meters
 }}
| abs_magnitude = 28.1<ref name="MPC-object"/>
}}

'''{{mp|2022 NX|1}}''' is a [[near-Earth object]] roughly {{convert|10|m|ft|sp=us}} in diameter discovered by Grzegorz Duszanowicz and Jordi Camarasa. The object orbits the Sun but makes slow close approaches to the Earth–Moon system. Between 11 June 2022 and 3 July 2022 (a period of {{time interval|2022-06-11|2022-07-03}}) it passed within Earth's [[Hill sphere]] (roughly {{convert|0.01|AU|e6km e6mi|abbr=unit}}) at a low relative velocity and became [[temporary satellite|temporarily captured]] by Earth's gravity, with a geocentric [[orbital eccentricity]] of less than 1<ref name="Horizons2022"/> and negative geocentric orbital energy.<ref name="minimoon"/> Due to its Earth-like orbit, the object might be of artificial origin or lunar ejecta.<ref name="MPEC2022-O04"/> However, visible spectroscopy obtained with the [[Gran Telescopio Canarias]] shows that it is an asteroid.<ref name="spectrum"/> The closest approach to Earth in 2022 was 26 June 2022 at roughly {{cvt|812200|km|mi}} when it had a relative velocity of {{convert|0.96|km/s|mph|abbr=on}}.<ref name=jpldata/> It was last near Earth around 16 January 1981 when it passed about {{cvt|600000|km|mi}} from Earth.<ref name=jpldata/> It will return as a [[temporary satellite]] in December 2051.<ref name="minimoon"/><ref name="spectrum"/>

{| class="wikitable" style="text-align:center; font-size: 0.9em;"
|+Entering and Exiting Geocentric Orbit<br/>(assuming the Earth+Asteroid are the only objects in the Solar System)
! [[Epoch (astronomy)|Epoch]]
! Earth distance<ref name="Horizons-Hill"/>
! Geocentric<br/>[[Orbital eccentricity|eccentricity]]<ref name="Horizons2022"/>
! [[Apsis|Apogee]]<ref name="Horizons2022"/>
! [[Orbital period]]<ref name="Horizons2022"/>
|-
|2022-Jun-11 || {{Convert|0.0077|AU|e6km|abbr=unit|lk=on}} ||1.024 ||<math>\infty</math> ||<math>\infty</math>
|-
|2022-Jun-12 || {{Convert|0.0075|AU|e6km|abbr=unit|lk=on}} ||0.997 ||{{Convert|3.6|AU|e6km|abbr=unit}} ||{{Convert|509532|day|year||order=flip}}
|-
|2022-Jun-21 || {{Convert|0.0058|AU|e6km|abbr=unit|lk=on}} ||0.815 ||{{Convert|0.054|AU|e6km|abbr=unit}} ||{{Convert|1067|day|year||order=flip}}
|-
|2022-Jul-02 || {{Convert|0.0058|AU|e6km|abbr=unit|lk=on}} ||0.987 ||{{Convert|0.82|AU|e6km|abbr=unit}} ||{{Convert|56465|day|year||order=flip}}
|-
|2022-Jul-03 || {{Convert|0.0059|AU|e6km|abbr=unit|lk=on}} ||1.008 ||<math>\infty</math> ||<math>\infty</math>
|}

The object was discovered on 2 July 2022 by Moonbase South Observatory in [[Namibia]] when it had a deep [[Southern hemisphere|Southern Hemisphere]] [[declination]] of –59° in the [[constellation]] of [[Pavo (constellation)|Pavo]].<ref name="MPEC2022-O04"/>

With a 56-day [[observation arc]] the object shows a 1.2% chance of [[Impact event|impacting]] Earth between the years of 2075–2122.<ref name=sentry/> This asteroid experienced a temporarily-captured flyby in 1981, had another one in 2022, and the current observation arc predicts it will become a mini-moon again in 2051.<ref name="minimoon"/><ref name="spectrum"/>

The [[reflectance spectrum]] of 2022 NX<sub>1</sub> suggests that its origin is not artificial and also that it is not lunar ejecta;<ref name="spectrum"/> it is also different from the [[asteroid spectral types|V type]] of the only other mini-moon with available spectroscopy, {{mpl|2020 CD|3}}. The visible spectrum of 2022 NX<sub>1</sub> is consistent with that of a [[asteroid spectral types|K-type asteroid]], although it could also be classified as an [[asteroid spectral types|Xk type]].<ref name="spectrum"/> Considering typical values of the similar albedo of both K-type and Xk-type asteroids and its absolute magnitude, 2022 NX<sub>1</sub> may have a size range of 5 to 15 m.<ref name="spectrum"/>

== See also ==
* {{mpl|1991 VG}}{{Snd}} near-Earth asteroid temporarily captured by Earth after its discovery in 1991
* {{mpl|2006 RH|120}}{{Snd}} the first temporary Earth satellite discovered ''in situ'' 2006
* {{mpl|2020 CD|3}}{{Snd}} another temporary Earth satellite discovered in 2020
* {{mpl|2024 PT|5}}{{Snd}} another temporary Earth satellite discovered in 2024
* [[2020 SO]]{{Snd}} a suspected near-Earth object identified as a [[Centaur (rocket stage)|rocket booster]] from the [[Surveyor 2]] mission

== References ==
{{Reflist|refs=

<ref name="MPEC2022-O04">{{cite web
  |title=MPEC 2022-O04 : 2022 NX1
  |publisher=IAU Minor Planet Center
  |date=2022-07-17
  |url=https://minorplanetcenter.net/mpec/K22/K22O04.html
  |accessdate=2022-07-18}} (K22N01X)</ref>

<ref name=jpldata>{{cite web
  |type=last observation: 2022-08-02; [[Observation arc|arc]]: 31 days (167 obs)
  |title=JPL Small-Body Database Browser: (2022 NX1)
  |url=https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2022NX1&view=OPC
  |publisher=[[Jet Propulsion Laboratory]]
  |archive-url=https://archive.today/20220718031217/https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html%23/?sstr=2022NX1&view=OPC
  |archive-date=2022-07-18
  |url-status=live
  |accessdate=2022-07-18}}</ref>

<ref name="MPC-object">{{cite web
  |title=2022 NX1 Orbit
  |work=Minor Planet Center
  |url=https://www.minorplanetcenter.net/db_search/show_object?object_id=2022+NX1
  |archive-url=https://web.archive.org/web/20220719023808/https://www.minorplanetcenter.net/db_search/show_object?object_id=2022+NX1
  |archive-date=2022-07-19
  |url-status=live
  |accessdate=2022-07-18}}</ref>

<ref name=sentry>{{cite web
  |title=Earth Impact Risk Summary: 2022 NX1
  |publisher=NASA/JPL Near-Earth Object Program Office
  |url=https://cneos.jpl.nasa.gov/sentry/details.html#?des=2022%20NX1
  |archive-url=https://archive.today/20220727092819/https://cneos.jpl.nasa.gov/sentry/details.html%23?des=2022%20NX1
  |archive-date=2022-07-27
  |url-status=live
  |accessdate=2022-07-27}}</ref>

<ref name="minimoon">{{cite journal
  |last1=de la Fuente Marcos|first1=Carlos
  |last2=de la Fuente Marcos|first2=Raúl
  |date=12 August 2022
  |title=How to Become a Mini-moon: Some Hints from 2022 NX<sub>1</sub>
  |journal=[[Research Notes of the AAS]]
  |volume=6 |issue=8 |pages=160 
  |arxiv=|bibcode=2022RNAAS...6..160D
  |doi=10.3847/2515-5172/ac8809
  |s2cid=251538919
 |doi-access=free}}</ref>

<ref name="Horizons2022">{{cite web
  |title=JPL Horizons On-Line Ephemeris for 2022 NX1 orbit of Earth (geocentric) for June – July 2022
  |work=[[JPL Horizons On-Line Ephemeris System]]
  |publisher=[[Jet Propulsion Laboratory]]
  |url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272022+NX1%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272022-Jun-01%27&STOP_TIME=%272022-Jul-31%27&STEP_SIZE=%271%20day%27&CENTER=%27@399%27&OUT_UNITS=%27AU-D%27
  |archive-url=https://web.archive.org/web/20220718130259/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272022+NX1%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272022-Jun-01%27&STOP_TIME=%272022-Jul-31%27&STEP_SIZE=%271+day%27&CENTER=%27%40399%27&OUT_UNITS=%27AU-D%27
  |archive-date=2022-07-18
  |url-status=live
  |access-date=2022-07-18}} Geocentric solution. Ephemeris Type: Orbital Elements / Center: @399</ref>

<ref name="Horizons-Hill">{{cite web
  |title=Horizons Batch for June – July 2022 Geocentric distance
  |type=Escaping Earth's Hill Sphere @ ~0.01au
  |publisher=[[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272022+NX1%27&START_TIME=%272022-Jun-01%27&STOP_TIME=%272022-July-31%27&STEP_SIZE=%271%20day%27&QUANTITIES=%2720%27
  |archive-url=https://web.archive.org/web/20220718134350/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272022+NX1%27&START_TIME=%272022-Jun-01%27&STOP_TIME=%272022-July-31%27&STEP_SIZE=%271+day%27&QUANTITIES=%2720%27
  |archive-date=2022-07-18
  |url-status=live
  |accessdate=2022-07-18}} (JPL#2/Soln.date: 2022-Jul-18)</ref>

<ref name="perihelion">{{cite web
  |title=Horizons Batch for perihelion on 2022-Dec-14
  |publisher=[[JPL Horizons On-Line Ephemeris System|JPL Horizons]]
  |url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272022+NX1%27&START_TIME=%272022-12-10%27&STOP_TIME=%272023-01-15%27&STEP_SIZE=%274%20hour%27&QUANTITIES=%2719%27
  |accessdate=2022-07-18}}</ref>

<ref name="geocentric">{{cite web
  |title=JPL Horizons On-Line Ephemeris for 2022 NX1 orbit of Earth (geocentric) at epoch 2022-Aug-09
  |url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272022+NX1%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272022-Aug-09%27&STOP_TIME=%272100-Jan-01%27&STEP_SIZE=%27100%20years%27&CENTER=%27@399%27&OUT_UNITS=%27AU-D%27
  |work=[[JPL Horizons On-Line Ephemeris System]]
  |publisher=[[Jet Propulsion Laboratory]]
  |access-date=2022-08-21}} Geocentric solution. Ephemeris Type: Orbital Elements / Center: @399 / Time Span: 2022-Aug-09 (to match infobox epoch)</ref>

<ref name="spectrum">{{cite journal
  |last1=de la Fuente Marcos|first1=Raúl
  |first2=Julia |last2=de León
  |last3=de la Fuente Marcos|first3=Carlos
  |first4=Javier |last4=Licandro
  |first5=Miquel |last5=Serra-Ricart
  |first6=Antonio |last6=Cabrera-Lavers
  |date=2 February 2023
  |title=Mini-moons from horseshoes: A physical characterization of 2022 NX<sub>1</sub> with OSIRIS at the 10.4 m Gran Telescopio Canarias
  |journal=Astronomy & Astrophysics Letters
  |volume=670 |issue=1 |pages=L10 (8 pages) 
  |arxiv=2301.10797|bibcode=2023A&A...670L..10D
  |doi=10.1051/0004-6361/202245514
 |url=https://www.aanda.org/articles/aa/full_html/2023/02/aa45514-22/aa45514-22.html | doi-access=free}}</ref>

}} <!-- end of reflist-->

== External links ==
* [https://twitter.com/tony873004/status/1548858310924836869 It came from below. Newly-discovered 2022 NX1 briefly entered Earth's orbit (ecc < 1) through the L1 point.] (Tony Dunn 17 July 2022)

{{2022 in space}}
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{{DEFAULTSORT:2022 NX1}}
[[Category:Apollo asteroids|#]]
[[Category:Minor planet object articles (unnumbered)]]
[[Category:Earth co-orbital asteroids|#]]
[[Category:Near-Earth objects in 2022|20220626]]
[[Category:Astronomical objects discovered in 2022|20220702]]
[[Category:Potential impact events caused by near-Earth objects]]