View source for (276033) 2002 AJ129

{{DISPLAYTITLE:{{mp|(276033) 2002 AJ|129}}}}
{{Use dmy dates|date=October 2019}}
{{Infobox planet
 | minorplanet     = yes
 | background      = #FFC2E0
 | name            = {{mp|(276033) 2002 AJ|129}}
 | image           = 2002 AJ129-orbit (multilingual).svg
 | image_scale      =
 | caption         = The orbit is highly elliptical, moving outside Mars and inside Mercury. Positions shown for 31 January 2018 before flyby.
 | discovery_ref   = <ref name="MPEC2002-B14" /><ref name="MPC-object" />
 | discoverer      = [[Near-Earth Asteroid Tracking|NEAT]]
 | discovery_site  = [[Haleakala Observatory|Haleakala Obs.]]
 | discovered      = 15 January 2002
 | mpc_name        = (276033) {{mp|2002 AJ|129}}
 | alt_names       = {{mp|2002 AJ|129}}
 | pronounced      = 
 | named_after     = 
 | mp_category = {{Ubl
  | [[Apollo asteroid|Apollo]]
  | [[Near-Earth object|NEO]]
  | [[Potentially hazardous object|PHA]]<ref name="jpldata" /><ref name="MPC-object" />
  | [[Mercury-crosser]]
  | [[Venus-crosser]]
  }}
 | orbit_ref       = <ref name="jpldata" /><ref name="AstDys" />
 | epoch           = 4 September 2017 ([[Julian day|JD]]&nbsp;2458000.5)
 | uncertainty     = 0
 | observation_arc = 14.23&nbsp;[[Julian year (astronomy)|yr]] (5,199 days)
 | aphelion        = 2.6254&nbsp;[[Astronomical unit|AU]]
 | perihelion      = 0.1167&nbsp;AU
 | semimajor       = 1.3711&nbsp;AU
 | eccentricity    = 0.9149
 | period          = 1.61&nbsp;[[Julian year (astronomy)|yr]] (586 days)
 | mean_anomaly    = 288.23[[Degree (angle)|°]]
 | mean_motion     = {{Deg2DMS|0.6139|sup=ms}} / day
 | inclination     = 15.449°
 | asc_node        = 138.05°
 | arg_peri        = 211.01°
 | moid            = 0.0060&nbsp;AU (2.3&nbsp;[[Lunar distance (astronomy)|LD]])
 | mean_diameter   = 0.5–1.2&nbsp;km<ref name="NeoDys" />
 | rotation        = 
 | albedo          = 
 | spectral_type   = 
 | abs_magnitude   = 18.7<ref name="jpldata" />
}}

'''{{mp|(276033) 2002 AJ|129}}''', provisional designation {{mp|2002 AJ|129}}, is a [[List of Mercury-crossing minor planets|Mercury-crossing asteroid]]. It has the ninth-smallest perihelion of all numbered asteroids, after asteroids such as {{mpl-|137924|2000 BD|19}}, {{mpl-|374158|2004 UL}}, and {{mpl-|386454|2008 XM}}.<ref name="JPLcrosserlist" /> It makes close approaches to all of the [[inner planets]]<ref name="jpldata" /> and asteroid [[4 Vesta]].<ref name="NEODyS-CA" /> The asteroid is estimated to be between {{convert|0.5|-|1.2|km|mi|sigfig=1|sp=us}} across.<ref name="NeoDys" /> In January 2018 there was much media hype about this asteroid being classified as a [[potentially hazardous asteroid]], although there is no known threat of an impact for hundreds if not thousands of years. The media has compared the size of the asteroid to the [[Burj Khalifa]] in Dubai.<ref name="Business-Insider" />

== Description ==

{{mp|2002 AJ|129}} was discovered on 15 January 2002 by astronomers of the [[Near-Earth Asteroid Tracking|NEAT]] team at [[Haleakala Observatory]], Hawaii, United States.<ref name="MPEC2002-B14" /><ref name="MPC-object" /> It was removed from the [[Sentry Risk Table]] on 3 February 2002.<ref name="Removed" />

It is a [[List of Mercury-crossing minor planets|Mercury-]], [[List of Venus-crossing minor planets|Venus-]], [[List of Earth-crossing minor planets|Earth-]] and [[List of Mars-crossing minor planets|Mars-crossing asteroid]]. With an [[observation arc]] of 14 years, it has a well determined orbit and was last observed in 2016.<ref name="jpldata" /> It is classified as an [[Apollo asteroid]]<ref name="jpldata" /> because it is a [[near-Earth asteroid]] with a [[semi-major axis]] larger than Earth's. It is also categorized as a [[potentially hazardous asteroid]],<ref name="jpldata" /> but that does not mean there is a near-term threat of an impact. It is a potentially hazardous asteroid merely as a result of its size ([[Absolute magnitude#Solar System bodies (H)|absolute magnitude]] {{nowrap|''H'' ≤ 22}}) and Earth [[minimum orbit intersection distance]] {{nowrap|(''Earth MOID'' ≤ 0.05&nbsp;AU}}).

=== 2018 approach ===

On 4 February 2018 at 21:31&nbsp;[[Universal Time|UT]], the asteroid passed about {{convert|0.028126|AU|km mi|abbr=on}} from Earth.<ref name="jpldata" /><ref name="JPL-news" /> The 2018 Earth approach distance was known with a [[3-sigma]] accuracy of ±200&nbsp;km.<ref name="jpldata" /> [[Goldstone Deep Space Communications Complex|Goldstone]] is scheduled to observe the asteroid from 3 to 6 February.<ref name="Goldstone"/> By 4 February 2018 11:00 UT, the asteroid brightened to [[apparent magnitude]] 14 and had a [[solar elongation]] of more than 100[[Degree (angle)|°]].<ref name="NEODyS2018"/>

=== 2172 approach ===

On 8 February 2172, the asteroid will pass about {{convert|0.00458|AU|km mi|abbr=on}} from Earth.<ref name="jpldata" /> The 2172 Earth approach distance is known with a [[3-sigma]] accuracy of ±4000&nbsp;km.

As we look even further into the future the known trajectory becomes more [[wikt:divergent|divergent]]. By the Earth approach of {{convert|0.24|AU|km mi|abbr=on}} on 19 February 2196 the uncertainty increases to ±2.4 million&nbsp;km.<ref name="jpldata" />

{{Large_near_earth_asteroid_flybys 2LD}}

== References ==
{{Reflist|refs=

<ref name="jpldata">{{cite web
  |type       = 2016-04-10 last obs.
  |title      = JPL Small-Body Database Browser: 276033 (2002 AJ129)
  |url        = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2276033;cad=1
  |publisher  = [[Jet Propulsion Laboratory]]
  |archiveurl = https://web.archive.org/web/20180118221442/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2002AJ129;cad=1
  |archivedate= January 18, 2018
  |url-status   = live
  |accessdate = 8 February 2018}}</ref>

<ref name="MPC-object">{{cite web
  |title      = 276033 (2002 AJ129)
  |work       = Minor Planet Center
  |url        = https://www.minorplanetcenter.net/db_search/show_object?object_id=276033
  |accessdate = 8 February 2018}}</ref>

<ref name="AstDys">[https://newton.spacedys.com/astdys/index.php?pc=1.1.0&n=276033 AstDys-2] Retrieved 2011 September 13</ref>

<ref name="NeoDys">[https://newton.spacedys.com/neodys2/index.php?pc=1.1.9&n=276033 NeoDys-2] Retrieved 2011 September 13</ref>

<ref name="NEODyS-CA">[https://newton.spacedys.com/neodys2/index.php?pc=1.1.8&n=276033 NEODyS-2 Close approaches]</ref>

<ref name="JPLcrosserlist">[http://ssd.jpl.nasa.gov/sbdb_query.cgi?obj_group=all;obj_kind=ast;obj_numbered=all;OBJ_field=0;ORB_field=0;c1_group=ORB;c1_item=Bi;c1_op=%3C;c1_value=0.3075;table_format=HTML;max_rows=200;format_option=comp;c_fields=BgBhBiBjBnBsChAcCq;.cgifields=format_option;.cgifields=ast_orbit_class;.cgifields=table_format;.cgifields=obj_kind;.cgifields=obj_group;.cgifields=obj_numbered;.cgifields=com_orbit_class&query=1&c_sort=BiA List of asteroids with q<0.3075&nbsp;AU generated by the JPL Small-Body Database Search Engine] Retrieved 2011 September 10</ref>

<ref name="MPEC2002-B14">{{cite web
  |title=MPEC 2002-B14 : 2002 AJ129
  |publisher=[[IAU Minor Planet Center]]
  |date=2002-01-19
  |url=https://www.minorplanetcenter.net/mpec/K02/K02B14.html
  |accessdate=2018-01-19}} (K02AC9J)</ref>

<ref name="Removed">{{Cite web |url=http://neo.jpl.nasa.gov/risk/removed.html |title=NEOs Removed from Impact Risks Tables |url-status=dead |archive-url=https://web.archive.org/web/20020602101400/http://neo.jpl.nasa.gov/risk/removed.html |archive-date=2 June 2002 }}</ref>

<ref name="Business-Insider">{{cite web|title=A 'potentially hazardous' asteroid bigger than Burj Khalifa is about to fly near our planet|url=http://www.businessinsider.com/potentially-dangerous-near-earth-object-asteroid-2002-aj129-2018-1|publisher=Business Insider|accessdate=January 19, 2018}}</ref>

<ref name="Goldstone">{{cite web
  |date=2018-02-01
  |title=Goldstone Radar Observations Planning: Asteroids 2002 AJ129, 2014 SR339, and 2015 BN509
  |publisher=NASA/JPL Asteroid Radar Research
  |author=Dr. Lance A. M. Benner
  |url=https://echo.jpl.nasa.gov/asteroids/2002AJ129/2002AJ129_planning.2018.html
  |accessdate=2018-02-03}}</ref>

<ref name="JPL-news">{{cite web
  |title      = Asteroid 2002 AJ129 to Fly Safely Past Earth February 4 [2018]
  |work       = NASA/Jet Propulsion Laboratory
  |date       = 19 January 2018
  |url        = https://www.jpl.nasa.gov/news/news.php?feature=7042
  |accessdate = 8 February 2018}}</ref>

<ref name="NEODyS2018">{{cite web
  |title=(276033) 2002AJ129 Ephemerides for February 2018
  |publisher=[[NEODyS]] (Near Earth Objects{{Snd}} Dynamic Site)
  |url=https://newton.spacedys.com/neodys2/index.php?pc=1.1.3.1&n=276033&oc=500&y0=2018&m0=2&d0=1&h0=0&mi0=0&y1=2018&m1=2&d1=10&h1=0&mi1=0&ti=12.0&tiu=hours
  |accessdate=2018-02-03}}</ref>

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

== External links ==
{{Commons category}}
* {{NeoDys|276033}}
* {{ESA-SSA|276033|2002AJ129}}
* {{JPL small body}}

{{Minor planets navigator | |number=276033 |PageName={{mp|(276033) 2002 AJ|129}} | }}
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{{DEFAULTSORT:2002 AJ129}}
[[Category:Apollo asteroids|276033]]
[[Category:Discoveries by NEAT|276033]]
[[Category:Earth-crossing asteroids|276033]]
[[Category:Mercury-crossing asteroids|276033]]
[[Category:Venus-crossing asteroids|276033]]
[[Category:Potentially hazardous asteroids|276033]]
[[Category:Near-Earth objects removed from the Sentry Risk Table|276033]]
[[Category:Near-Earth objects in 2018]]
[[Category:Astronomical objects discovered in 2002|20020115]]