View source for (410777) 2009 FD

{{Short description|Asteroid}}
{{Use dmy dates|date=October 2019}}
{{Infobox planet
 | minorplanet     = yes
 | name            = (410777) 2009 FD
 | background      = #FFC2E0
 | image           = 2009 FD.png
 | image_scale      =
 | caption         = [[Arecibo Observatory]] radar images of {{mp|2009 FD}}
 | discovery_ref   = <ref name="jpldata" />
 | discoverer      = [[Spacewatch]]
 | discovery_site  = {{nowrap|[[Kitt Peak National Observatory|Kitt Peak National Obs.]]}}
 | discovered      = 24 February 2009
 | mpc_name        = (410777) 2009 FD
 | alt_names       = 2009 FD
 | pronounced      = 
 | named_after     = 
 | mp_category     = {{Hlist
  | [[Apollo asteroid|Apollo]]
  | [[Near-Earth object|NEO]]
  | [[Potentially hazardous object|PHA]]<ref name="jpldata"/><ref name="MPC-object"/>
  }}
 | orbit_ref       = <ref name="jpldata" />
 | epoch           = 3 July 2013 ([[Julian day|JD]]&nbsp;2456476.5)
 | uncertainty     = 0
 | observation_arc = 6.77&nbsp;yr (2,471 days)
 | aphelion        = 1.7361&nbsp;[[Astronomical unit|AU]]
 | perihelion      = 0.5896&nbsp;AU
 | semimajor       = 1.1629&nbsp;AU
 | eccentricity    = 0.4929
 | period          = 1.25&nbsp;[[Julian year (astronomy)|yr]] (458 days)
 | mean_anomaly    = 98.579[[Degree (angle)|°]]
 | mean_motion     = {{Deg2DMS|0.7860|sup=ms}} / day
 | inclination     = 3.1366°
 | asc_node        = 9.5523°
 | arg_peri        = 281.24°
 | satellites      = 1<ref name="johnstonsarchive" />
 | moid            = 0.0025&nbsp;AU (1&nbsp;[[Lunar distance (astronomy)|LD]])
 | mean_diameter   = {{Ubl
  | 0.113&nbsp;km {{small|(calculated)}}<ref name="lcdb" />
  | {{val|0.150|u=km}}{{efn|name=lcdb-Naidu-2015d}}
  | {{val|0.472|u=km}}<ref name="Mainzer-2014" />
  | {{small|Primary:}} 120–180&nbsp;m
  | {{small|Secondary:}} 60–120&nbsp;m<ref name="CBAT4191"/>
  }}
 | mass            = {{val|8.3|e=10|u=kg}}&nbsp;{{small|(assumed)}}<ref name=summary/>
 | rotation        = {{Ubl
  | {{val|2.5|ul=h}} {{small|(at least)}}{{efn|name=lcdb-Naidu-2015d}}
  | {{val|4.0|u=h}}<ref name="geneva-obs" />
  | {{val|5.87|0.02|u=h}}<ref name="Carbognani-2011a" />
  | {{val|6.22|0.41|u=h}}<ref name="Koehn-2014" />
  }}
 | albedo          = {{Ubl
  | {{val|0.01}}<ref name="Mainzer-2014" />
  | 0.20 {{small|(assumed)}}<ref name="lcdb" />
  }}
 | spectral_type   = {{Hlist
  | [[C-type asteroid|C]]<ref name=Spoto2014/>
  | [[S-type asteroid|S]] {{small|(assumed)}}<ref name="lcdb" />
  }}
 | abs_magnitude   = 22.1<ref name="jpldata" /><ref name="lcdb" />
}}

'''(410777) 2009 FD''' is a [[carbonaceous]] sub-kilometer [[asteroid]] and [[Binary asteroid|binary system]],<ref name="CBAT4191"/><ref name="johnstonsarchive" /> classified as [[near-Earth object]] and [[potentially hazardous asteroid]] of the [[Apollo asteroid|Apollo group]], discovered on 24 February 2009 by astronomers of the [[Spacewatch]] program at [[Kitt Peak National Observatory]] near Tucson, Arizona, in the United States.<ref name="MPC-object"/>

Until 2019, the asteroid's modelled orbit placed it at risk of a possible future collision with [[Earth]] in 2185. With a [[Palermo scale]] rating of -0.44, it had the fifth highest [[Impact event|impact threat]]{{efn|name=palermo}} of all known asteroids based on its estimated diameter, kinetic yield, impact probability, and time interval.<ref name="risk-table2016"/> Observations in 2019 extended the [[observation arc]] by four years and detected a favourable [[Yarkovsky effect]], which ruled out impact in 2185.<ref name="DelVigna2019"/> Using observations from 16 November 2020, the asteroid was removed from the Sentry risk table on 19 November 2020.

== Discovery==
[[File:The VLT images the very faint Near-Earth Object 2009 FD.jpg|thumb|left|2009 FD imaged by the [[Very Large Telescope]] in November 2013]]

{{mp|2009 FD}} was initially announced as discovered on 16 March 2009 by [[Observatorio Astronómico de La Sagra|La Sagra Sky Survey]].<ref name="MPEC2009-F09"/> Because there were previous observations found in images taken by the [[Spacewatch]] survey some 3 weeks prior, on 24 February 2009, the [[Minor Planet Center]] assigned the discovery credit to [[Spacewatch]] under the discovery assignment rules.<ref name="MPEC2010-U20"/><ref name="MPC-object"/> {{mp|2009 FD}} made a close pass to Earth on 27 March 2009 at a distance of {{convert|0.004172|AU|km mi|abbr=on|lk=on}}<ref name=jpl-close/><ref>[http://www.iceinspace.com.au/forum/showthread.php?t=42946 Near Earth Asteroid 2009 FD - whilst you were sleeping! (ice in space)]</ref> and another on 24 October 2010 at 0.0702 AU.<ref name=jpl-close/> {{mp|2009 FD}} was recovered at [[apparent magnitude]] 23{{efn|name=visibility}} on 30 November 2013 by [[Cerro Paranal Observatory]],<ref name="MPC-object"/> several months before the close approach of April 2014 when it passed 0.1&nbsp;AU from Earth.<ref name=jpl-close/> It brightened to roughly apparent magnitude 19.3 around mid-March 2014.<ref name="NEODyS2014"/> One [[radar astronomy|radar]] Doppler observation of {{mp|2009 FD}} was made in 2014.<ref name="jpldata"/> The October–November 2015 Earth approach was studied by the [[Goldstone Deep Space Communications Complex|Goldstone Deep Space Network]].<ref name="Goldstone-sch"/>

== Binary ==

NASA's Near Earth Program originally estimated its size to be 130 metres in diameter based on an assumed [[Albedo#Astronomical albedo|albedo]] of 0.15.<ref name=Wayback110111/> This gave it an estimated mass of around 2,800,000 tonnes.<ref name=Wayback110111/> But work by [[Amy Mainzer]] using [[NEOWISE]] data in 2014 showed that it could be as large as 472 metres with an albedo as low as 0.01.<ref name="jpldata"/><ref name="Mainzer-2014" /> Because {{mp|2009 FD}} (K09F00D) was only detected in two (W1+W2) of the four wavelengths the suspected NEOWISE diameter is more of an upper limit.<ref name="Mainzer-2014" /> Radar observations in 2015 showed it to be a binary asteroid.<ref name="CBAT4191"/> The primary is 120–180 meters in diameter and the secondary is 60–120 meters in diameter.<ref name="CBAT4191"/>

== Future approaches==

The [[JPL Small-Body Database]] shows that {{mp|2009 FD}} will make two very close approaches in the late 22nd century, in 2185 and 2190. As of 2016, the approach of 29 March 2185 had a 1 in 710 chance of impacting Earth.<ref name=summary/> The [[Curve fitting|nominal]] 2185 Earth approach distance was {{convert|0.009|AU|km mi|abbr=on|lk=off}}.<ref name=jpl-close/> [[Orbit determination]] for 2190 is complicated by the 2185 close approach.<ref name=jpl-close/> The precise distance that it will pass from Earth and the Moon on 29 March 2185 will determine the 30 March 2190 distance. {{mp|2009 FD}} should pass closer to the Moon than Earth on 29 March 2185.<ref name=jpl-close/> An impact by {{mp|2009 FD}} would cause severe devastation to a large region or tsunamis of significant size.<ref>{{cite web |url=http://www.oecd.org/dataoecd/18/40/2493218.pdf |title=How a Near-Earth Object Impact Might Affect Society |date=9 January 2003 |first=Clark R. |last=Chapman |website=[[OECD]] |accessdate=14 November 2018 |url-status=dead |archiveurl=https://web.archive.org/web/20050217164636/http://www.oecd.org/dataoecd/18/40/2493218.pdf |archivedate=17 February 2005}}</ref><!-- dummy edit; can be deleted. -->

=== Past Earth-impact estimates ===

In January 2011, near-Earth asteroid {{mp|2009 FD}} (with observations through 7 December 2010) was listed on the JPL Sentry Risk Table with a 1 in 435 chance of impacting Earth on 29 March 2185.<ref name=Wayback110111/> In 2014 (with observations through 5 February 2014, creating an [[observation arc]] of 1807 days) the potential 2185 impact was ruled out.<ref name=Wayback140210/> Using the 2014 observations, the [[Yarkovsky effect]] has become more significant than the position uncertainties.<ref name="NEODyS"/><ref name=Spoto2014/><ref name="notes"/> The Yarkovsky effect has resulted in the 2185 virtual impactor returning. While {{mp|2009 FD}} was estimated to be 470 meters in diameter, it was rated −0.40 on the [[Palermo scale]], placing it higher on the [[Sentry Risk Table]] than any other known object at the time.<ref name="risk-table2016">{{Cite web |url=http://neo.jpl.nasa.gov/risk/ |title=Sentry Risk Table |website=NASA Near-Earth Object Program |access-date=8 June 2012 |archive-url=https://web.archive.org/web/20160121035736/http://neo.jpl.nasa.gov/risk/ |archive-date=21 January 2016 |url-status=dead }}</ref>

On 14 June 2019, Alessio Del Vigna and colleagues published a new analysis, which incorporates astrometry taken in 2019. Using both [[Jet Propulsion Laboratory|JPL]]'s Sentry as well as [[NEODyS]]'s CLOMON-2 system, the new data allowed a 4-[[standard deviation|sigma]] detection of the Yarkovsky effect at {{val|+3.6|0.9|e=-3|u=[[Astronomical Unit|AU]]/[[Megayear|Myr]]}}. The 2019 observations extended the observation arc from six years to ten years. This ruled out the 2185 impact possibility, leaving the potential impact in 2190 as the only theoretically possible impact until 2250, at a very low probability of 1 in 100 million.<ref name="DelVigna2019"/> On 19 November 2020, the asteroid was finally completely removed from the sentry risk table as all possible impacts, including 2190 and 2250, were ruled out.

== See also ==
* [[List of asteroid close approaches to Earth]], for other close approaches

== Notes ==
{{notelist|refs=

{{efn|name=lcdb-Naidu-2015d|1=Naidu, S. (2015) from observations taken in November 2015: Per private communication with the LCDB. Rotation period of at least {{val|2.5}} hours. Diameter estimate of 0.150 kilometers. Summary figures for (410777) at the [http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=410777%7C LCDB]}}

{{efn|name=visibility|1=At an [[apparent magnitude]] of 23, {{mp|2009 FD}} was roughly 4 million times fainter than can be seen with the [[naked eye]].<br />Math: <math>(\sqrt[5]{100})^{23-6.5}\approx 3981071</math>}}

{{efn|name=palermo|Behind: [[99942 Apophis]] @ 1.10, {{mpl|(89959) 2002 NT|7}} @ 0.18, [[(29075) 1950 DA]] @ 0.17, {{mpl|(144898) 2004 VD|17}} @ -0.25}}

}} <!-- end of notelist -->

== References ==
{{reflist|refs=

<ref name="jpldata">{{cite web
  |type       = 2015-12-01 last obs.
  |title      = JPL Small-Body Database Browser: 410777 (2009 FD)
  |url        = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2410777
  |archive-url = https://web.archive.org/web/20191216204125/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2410777
  |url-status = dead
  |archive-date = 16 December 2019
  |publisher  = [[Jet Propulsion Laboratory]]
  |accessdate = 30 January 2018}}</ref>

<ref name="MPC-object">{{cite web
  |title      = 410777 (2009 FD)
  |work       = Minor Planet Center
  |url        = https://www.minorplanetcenter.net/db_search/show_object?object_id=410777
  |accessdate = 30 January 2018}}</ref>

<ref name="MPEC2009-F09">{{Cite web
  |title=MPEC 2009-F09 : 2009 FD
  |publisher=[[IAU Minor Planet Center]]
  |date=2009-03-17
  |url=https://www.minorplanetcenter.net/mpec/K09/K09F09.html
  |accessdate=2013-01-09}} (K09F00D)</ref>

<ref name="MPEC2010-U20">{{Cite web
  |title=MPEC 2010-U20 : Editorial Notice
  |publisher=IAU Minor Planet Center
  |date=2010-10-19
  |url=https://www.minorplanetcenter.net/mpec/K10/K10U20.html
  |accessdate=2014-12-29}}</ref>

<ref name="johnstonsarchive">{{cite web
  |title      = Asteroids with Satellites Database – (410777) 2009 FD
  |work       = Johnston's Archive
  |date       = 27 November 2015
  |author     = Johnston, Wm. Robert
  |url        = http://www.johnstonsarchive.net/astro/astmoons/am-410777.html
  |accessdate = 30 January 2018}}</ref>

<ref name=summary>{{cite web
 |title       = Earth Impact Risk Summary: 2009 FD
 |publisher   = NASA/JPL Near-Earth Object Program Office
 |url         = https://cneos.jpl.nasa.gov/sentry/details.html#?des=410777
 |archiveurl  = https://web.archive.org/web/20160118111518/http://neo.jpl.nasa.gov/risk/a410777.html#?des=410777
 |archivedate = January 18, 2016
 |url-status    = live
 |accessdate  = 2014-05-01 }}</ref>

<ref name="NEODyS">{{cite web
  |title=(410777) 2009FD
  |publisher=[[NEODyS]] (Near Earth Objects{{Snd}} Dynamic Site)
  |url=https://newton.spacedys.com/neodys/index.php?pc=1.1.2&n=2009FD
  |accessdate=2014-05-01}} ([https://archive.today/20140501163532/http://neo.jpl.nasa.gov/cgi-bin/ip?2.64e-3 2.64e-3] = 1 in 379 chance)</ref>

<ref name=jpl-close>{{cite web
 |type        = last observation: 2014-04-07; [[Observation arc|arc]]: 5.11 years
 |title       = JPL Close-Approach Data: (2009 FD)
 |url         = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009FD;cad=1#cad
 |archiveurl  = https://archive.today/20131219094659/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009FD;cad=1%23cad
 |archivedate = 19 December 2013
 |url-status    = dead
 |accessdate  = 2014-05-01 }}</ref>

<ref name="NEODyS2014">{{cite web
  |title=2009 FD Ephemerides for 1 April 2014
  |publisher=NEODyS (Near Earth Objects{{Snd}} Dynamic Site)
  |url=https://newton.spacedys.com/neodys/index.php?pc=1.1.3.1&n=2009FD&oc=500&y0=2014&m0=2&d0=25&h0=0&mi0=0&y1=2014&m1=4&d1=6&h1=0&mi1=0&ti=1.0&tiu=days
  |accessdate=2013-12-17}}</ref>

<ref name=Wayback110111>{{cite web|type=2011-01-11 computed on 14 December 2010 |title=Earth Impact Risk Summary: 2009 FD (arc=650 days) |publisher=Wayback Machine: JPL |url=http://neo.jpl.nasa.gov/risk/2009fd.html |accessdate=2014-02-14 |url-status=dead |archiveurl=https://web.archive.org/web/20110111142013/http://neo.jpl.nasa.gov/risk/2009fd.html |archivedate=11 January 2011 }} ([https://archive.today/20140214144606/http://neo.jpl.nasa.gov/cgi-bin/ip?2.3e-03 2.3e-03] = 1 in 435 chance)</ref>

<ref name=Wayback140210>{{cite web|type=2014-02-10 computed on 7 February 2014 |title=Earth Impact Risk Summary: 2009 FD (arc=1807 days) |publisher=Wayback Machine: JPL |url=http://neo.jpl.nasa.gov/risk/2009fd.html |accessdate=2014-05-01 |url-status=dead |archiveurl=https://web.archive.org/web/20140210154919/http://neo.jpl.nasa.gov/risk/2009fd.html |archivedate=10 February 2014 }}</ref>

<ref name="Goldstone-sch">{{cite web
  |date=2014-03-17
  |title=Goldstone Asteroid Schedule
  |publisher=NASA/JPL Asteroid Radar Research
  |author=Dr. Lance A. M. Benner
  |url=http://echo.jpl.nasa.gov/asteroids/goldstone_asteroid_schedule.html
  |archive-url=https://web.archive.org/web/19961119092614/http://echo.jpl.nasa.gov/asteroids/goldstone_asteroid_schedule.html
  |url-status=dead
  |archive-date=1996-11-19
  |accessdate=2014-03-21}}</ref>

<ref name="Mainzer-2014">{{Cite journal
  |display-authors = 6
  |first1     = A. |last1 = Mainzer
  |first2     = J. |last2 = Bauer
  |first3     = T. |last3 = Grav
  |first4     = J. |last4 = Masiero
  |first5     = R. M. |last5 = Cutri
  |first6     = E. |last6 = Wright
  |first7     = C. R. |last7 = Nugent
  |first8     = R. |last8 = Stevenson
  |first9     = E. |last9 = Clyne
  |first10    = G. |last10 = Cukrov
  |first11    = F. |last11 = Masci
  |date       = April 2014
  |title      = The Population of Tiny Near-Earth Objects Observed by NEOWISE
  |journal    = The Astrophysical Journal
  |volume     = 784
  |issue      = 2
  |page       = 27
  |bibcode    = 2014ApJ...784..110M
  |doi        = 10.1088/0004-637X/784/2/110
  |arxiv      = 1310.2980
  |s2cid = 45559179 }} (listed as K09F00D)</ref>

<ref name="notes">{{cite web
  |title=Sentry Notes 
  |publisher=NASA/JPL Near-Earth Object Program Office
  |url=http://neo.jpl.nasa.gov/risk/notes.shtml
  |archive-url=https://web.archive.org/web/20110216072654/http://neo.jpl.nasa.gov/risk/notes.shtml
  |url-status=dead
  |archive-date=2011-02-16
  |accessdate=2014-05-01}}</ref>

<ref name=Spoto2014>{{cite journal
  |author1=Spoto, F.
  |author2=Milani, A.
  |author3=Farnocchia, D.
  |author4=Chesley, S. R.
  |author5=Micheli
  |author6=Valsecchi
  |author7=Perna
  |author8=Hainaut
  |title=Non-gravitational Perturbations and Virtual Impactors: the case of asteroid 2009 FD
  |journal=Astronomy & Astrophysics
  |volume=572
  |pages=A100
  |arxiv=1408.0736|doi = 10.1051/0004-6361/201424743 |date=2014
  |bibcode=2014A&A...572A.100S|s2cid=55524612
 }}</ref>

<ref name="CBAT4191">{{Cite web
  |title=(410777) 2009 FD
  |publisher=Central Bureau for Astronomical Telegrams
  |date=2015-11-19
  |url=http://www.cbat.eps.harvard.edu/iau/cbet/004100/CBET004191.txt
  |archive-url=https://web.archive.org/web/20160304194434/http://www.cbat.eps.harvard.edu/iau/cbet/004100/CBET004191.txt
  |url-status=dead
  |archive-date=2016-03-04
  |accessdate=2017-07-09}}</ref>

<ref name="geneva-obs">{{cite web
  |title      = Asteroids and comets rotation curves – (410777) 2009 FD
  |last       = Behrend |first = Raoul
  |publisher  = [[Geneva Observatory]]
  |url        = http://obswww.unige.ch/~behrend/page5cou.html#09f00d
  |accessdate = 30 January 2018}}</ref>

<ref name="lcdb">{{cite web
  |title      = LCDB Data for (410777) 
  |publisher  = Asteroid Lightcurve Database (LCDB)
  |url        = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=410777%7C
  |accessdate = 30 January 2018}}</ref>

<ref name="Koehn-2014">{{Cite journal
  |display-authors = 6
  |first1     = Bruce W. |last1 = Koehn
  |first2     = Edward G. |last2 = Bowell
  |first3     = Brian A. |last3 = Skiff
  |first4     = Jason J. |last4 = Sanborn
  |first5     = Kyle P. |last5 = McLelland
  |first6     = Petr |last6 = Pravec
  |first7     = Brian D. |last7 = Warner
  |date       = October 2014
  |title      = Lowell Observatory Near-Earth Asteroid Photometric Survey (NEAPS) - 2009 January through 2009 June
  |journal    = The Minor Planet Bulletin
  |volume     = 41
  |issue      = 4
  |pages      = 286–300
  |issn       = 1052-8091
  |bibcode    = 2014MPBu...41..286K}}</ref>

<ref name="Carbognani-2011a">{{Cite journal
  |author     = Carbognani, Albino
  |date       = January 2011
  |title      = Lightcurves and Periods of Eighteen NEAs and MBAs
  |journal    = The Minor Planet Bulletin
  |volume     = 38
  |issue      = 1
  |pages      = 57–63
  |issn       = 1052-8091
  |bibcode    = 2011MPBu...38...57C}}</ref>

<ref name="DelVigna2019">{{Citation
  |author1    = Del Vigna, A.
  |author2    = Roa, J.
  |author3    = Farnocchia, D.
  |author4    = Micheli, M.
  |author5    = Guerra, F.
  |author6    = Spoto, F.
  |author7    = Valsecchi, G. B.
  |title      = Yarkovsky effect detection and updated impact hazard assessment for near-Earth asteroid (410777) 2009 FD
  |date       = 14 June 2019
  |journal    = Astronomy & Astrophysics
  |volume = 627
  |pages = L11
  |arxiv      = 1906.05696
  |doi = 10.1051/0004-6361/201936075
  |bibcode = 2019A&A...627L..11D|s2cid = 189762523
 }}</ref>

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

== External links ==
* [http://www.naic.edu/~pradar/ Planetary Radar Science Group]
* [http://www.eso.org/public/announcements/ann14004/ ESA/ESO Collaboration Successfully Tracks Its First Potentially Threatening Near-Earth Object] (ESO 21 January 2014)
* {{NeoDys|410777}}
* {{ESA-SSA|410777|2009FD}}
* {{JPL small body}}

{{Planetary defense}}
{{Minor planets navigator | |number=410777 | }}
{{Small Solar System bodies}}
{{2014 in space}}
{{Authority control}}

{{DEFAULTSORT:2009 FD}}
[[Category:Apollo asteroids|410777]]
[[Category:Discoveries by the Spacewatch project|410777]]
[[Category:Venus-crossing asteroids|410777]]
[[Category:Earth-crossing asteroids|410777]]
[[Category:Near-Earth objects removed from the Sentry Risk Table|410777]]
[[Category:Potentially hazardous asteroids|410777]]
[[Category:Binary asteroids|410777]]
[[Category:Near-Earth objects in 2014]]
[[Category:Astronomical objects discovered in 2009|20090224]]