{{Short description|American astronomical survey for identifying and tracking near-Earth objects}} {{Redirect|LINEAR||Linear (disambiguation)}} {{Infobox astronomical survey}} [[File:NEA by survey.png|thumb|260px|Number of [[near-Earth object|NEO]]s detected by various projects: {| style="width: 100%; margin-bottom: 8px;" |- | valign=top width=50% | {{legend2|#0000FF|border=1px solid #0000B3|'''LINEAR'''}}<br /> {{legend2|#FFA500|border=1px solid #B37400|[[Near Earth Asteroid Tracking|NEAT]]}}<br /> {{legend2|#FF0000|border=1px solid #800000|[[Spacewatch]]}}<br /> {{legend2|#FFFF00|border=1px solid #B3B300|[[LONEOS]]}} | valign=top | {{legend2|#008B00|border=1px solid #003D00|[[Catalina Sky Survey|CSS]]}}<br /> {{legend2|#FF00FF|border=1px solid #390052|[[Pan-STARRS]]}}<br /> {{legend2|#00CCCC|border=1px solid #333|[[NEOWISE]]}}<br /> {{legend2|#993300|border=1px solid #333|[[List of near-Earth object observation projects|All others]]}} |} ]]

The '''Lincoln Near-Earth Asteroid Research''' ('''LINEAR''') project is a collaboration of the [[United States Air Force]], [[NASA]], and the [[Massachusetts Institute of Technology]]'s [[Lincoln Laboratory]] for the systematic detection and tracking of [[near-Earth object]]s. LINEAR was responsible for the majority of [[asteroid]] discoveries from 1998 until it was overtaken by the [[Catalina Sky Survey]] in 2005.<ref name=NEO-STATS /> {{As of|2011|9|15|url=http://www.ll.mit.edu/mission/space/linear/}}, LINEAR had detected 231,082 new [[small Solar System bodies]], of which at least 2,423 were near-Earth asteroids and 279 were [[comet]]s.<ref name=LINEAR /> The instruments used by the LINEAR program are located at [[Lincoln Laboratory's Experimental Test Site]] (ETS) on the [[White Sands Missile Range]] (WSMR) near [[Socorro, New Mexico]].

== History ==

In the late 1970s, the ''Lincoln Laboratory's Experimental Test Site'' facility (observatory code [[IAU code#700–799|704]]) was built at White Sands Missile Range.<ref name=1980BEAT /><ref name="ETS" /> The project's prototype used low-light video cameras.<ref name=1981TAFF /> In 1994 a new proposal was made for automated detection of asteroids, this time using newer digital detector technology.<ref name=1994TENN /> The LINEAR project began operating a [[near-Earth object]] discovery facility in 1996 using a {{Convert|1.0|m|in|abbr=on}} [[aperture]] [[telescope]] designed for the [[Air Force Space Command]]'s [[Ground-based Electro-Optical Deep Space Surveillance]] (GEODSS). The wide-field Air Force telescopes were designed for optical observation of Earth-orbiting spacecraft. Initial field tests used a 1024&nbsp;×&nbsp;1024 [[pixel]] [[charge-coupled device]] (CCD) detector. While this CCD detector filled only about one fifth of the telescope's [[field of view]], four near-earth objects were discovered. A 1960&nbsp;×&nbsp;2560 pixel CCD which covered the telescope's two-[[square degree]] field of view was then installed, and both detectors were used in later tests.<ref name=NASA-LIN />

The first LINEAR telescope became fully operational in March 1998.<ref name=1998STOK /> Beginning in October 1999, a second 1.0&nbsp;m telescope was added to the search effort.<ref name=1999ELOW /> In 2002, a {{Convert|0.5|m|in|abbr=on}} telescope equipped with the original CCD was brought on-line to provide follow-up observations for the discoveries made by the two search telescopes.<ref name=2002STOK /> This allowed about 20% more of the sky to be searched each night. Data recorded by the telescopes is sent to a Lincoln Laboratory facility at [[Hanscom Air Force Base]] in [[Lexington, Massachusetts]] for processing. Detections are then forwarded to the [[Minor Planet Center]].<ref name=LINEAR />

== Discoveries == {{See also|Category:Discoveries by LINEAR}} {| class="wikitable floatright" style="font-size: 0.9em; width: 270px;" |+ [[Minor planet]]s discovered: 147,707<ref name="MPC-Discoverers" /> |- | ''see {{section link|List of minor planets|Main index}}'' |}

In addition to discovering more than 140,000 [[minor planet]]s, LINEAR is also credited with the discovery, or co-discovery, or rediscovery of several periodic comets, including [[11P/Tempel–Swift–LINEAR]], [[158P/Kowal-LINEAR]], [[160P/LINEAR]] (LINEAR 43), [[165P/LINEAR]] (LINEAR 10), and [[176P/LINEAR]] (LINEAR 52, 118401 LINEAR: one of only five objects classified both as comets and [[asteroid]]s). Other objects discovered include {{Mpl|(137108) 1999 AN|10}}, {{Mpl|(179806) 2002 TD|66}}, and [[2004 FH]]. One of LINEAR's discoveries {{Mpl|(231937) 2001 FO|32}} passed near the Earth on 21 March, 2021<ref>{{cite web |last1=February 2021 |first1=Patrick Pester-Staff Writer 22 |title=Asteroid the size of the Golden Gate Bridge will whiz past Earth in March |url=https://www.space.com/potentially-hazardous-asteroid-whizzes-near-earth-2001-fo32 |website=Space.com |date=22 February 2021 |access-date=2 March 2021 |language=en}}</ref>

== See also == * [[EURONEAR]] * [[List of comets discovered by the LINEAR project]] * {{section link|List of minor planet discoverers|Discovering dedicated institutions}} * [[Minor Planet Center]] * [[Planetary Data System]]

== References == {{Reflist|30em|refs=

<ref name=NEO-STATS>{{cite web |title=NEO Discovery Statistics |url=http://neo.jpl.nasa.gov/stats/ |archive-url=https://web.archive.org/web/20040513230213/http://neo.jpl.nasa.gov/stats/ |url-status=dead |archive-date=2004-05-13 |publisher=NASA Near Earth Object Program |access-date=2012-01-19}}</ref>

<ref name=LINEAR>{{cite web |title=MIT Lincoln Laboratory: LINEAR |url=http://www.ll.mit.edu/mission/space/linear/ |publisher=MIT Lincoln Laboratory |access-date=2012-01-19 |archive-url=https://web.archive.org/web/20170724185128/http://www.ll.mit.edu/mission/space/linear/ |archive-date=2017-07-24 |url-status=dead }}</ref>

<ref name="ETS">{{cite web |url=http://www.ll.mit.edu/mission/space/linear/ETS.html |title=LINEAR – Experimental Test Site |publisher=Lincoln Laboratory, MIT |access-date=3 November 2016 |archive-url=https://web.archive.org/web/20170626073250/http://www.ll.mit.edu/mission/space/linear/ETS.html |archive-date=26 June 2017 |url-status=dead }}</ref>

<ref name=1980BEAT>{{cite journal |bibcode=1980STIN...8112143B |title=Artificial satellites, minor planets, and the ETS |last1=Beatty |first1=D. E. |last2=Sorvari |first2=J. M. |last3=Taff |first3=L. G. |journal=NASA Sti/Recon Technical Report N |volume=81 |date=1980 |pages=12143 }}</ref>

<ref name=1981TAFF>{{cite journal |bibcode=1981PASP...93..658T |title=A new asteroid observation and search technique |last1=Taff |first1=L. G. |volume=93 |date=1981 |pages=658 |journal=Publications of the Astronomical Society of the Pacific |doi=10.1086/130905|doi-access=free }}</ref>

<ref name=1994TENN>{{cite book |doi=10.1117/12.176813 |title=Instrumentation in Astronomy VIII |journal=Proceedings of SPIE |date=1994 |last1=Tennyson |first1=Peter D. |last2=Rork |first2=Eugene W. |last3=Kostishack |first3=Daniel F. |editor-first1=David L. |editor-first2=Eric R. |editor-last1=Crawford |editor-last2=Craine |chapter=Applying electro-optical space surveillance technology to the detection of near-Earth asteroids |volume=2198 |pages=1286–1297|bibcode=1994SPIE.2198.1286T |s2cid=129557577 }}</ref>

<ref name=NASA-LIN>{{cite web |title=Lincoln Near-Earth Asteroid Research (LINEAR) |url=http://neo.jpl.nasa.gov/programs/linear.html |archive-url=https://web.archive.org/web/20040114170809/http://neo.jpl.nasa.gov/programs/linear.html |url-status=dead |archive-date=2004-01-14 |publisher=NASA Near Earth Object Program |access-date=2012-01-19}}</ref>

<ref name=1998STOK>{{cite journal |bibcode=1998DPS....30.1607S |title=Results from the Lincoln Near Earth Asteroid Research (LINEAR) Project |last1=Stokes |first1=G. H. |last2=Viggh |first2=H. E. M. |last3=Shelly |first3=F. L. |last4=Blythe |first4=M. S. |last5=Stuart |first5=J. S. |volume=30 |date=1998 |pages=1042 |journal=American Astronomical Society }}</ref>

<ref name=1999ELOW>{{cite journal |bibcode=1999AAS...19510801E |title=A Progress Report on the Lincoln Near Earth Asteroid Research Project |last1=Elowitz |first1=R. M. |last2=Stokes |first2=G. H. |last3=Bezpalko |first3=M. |last4=Blythe |first4=M. S. |last5=Evans |first5=J. B. |last6=Pearce |first6=E. C. |last7=Sayer |first7=R. W. |last8=Shelly |first8=F. C. |last9=Viggh |first9=H. E. M. |volume=195 |date=1999 |pages=1531 |journal=American Astronomical Society }}</ref>

<ref name=2002STOK>{{cite journal |bibcode=2002AAS...20113003S |title=LINEAR Search and Operations Experience |last1=Stokes |first1=G. H. |last2=Evans |first2=J. B. |last3=Shelly |first3=F. C. |volume=201 |date=2002 |pages=1315 |journal=American Astronomical Society }}</ref>

<ref name="MPC-Discoverers">{{cite web |title = Minor Planet Discoverers (by number) |work = Minor Planet Center |url = http://www.minorplanetcenter.net/iau/lists/MPDiscsNum.html |date = 12 January 2017 |access-date = 2 February 2017}}</ref>

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

== External links == *{{Cite web|url=http://www.ll.mit.edu/linear|title=LINEAR website|archive-url=https://web.archive.org/web/20080517053406/http://www.ll.mit.edu/linear|archive-date=2008-05-17}} *[https://web.archive.org/web/20170706083730/http://www.ll.mit.edu/publications/journal/pdf/vol11_no1/11_1linear.pdf The Lincoln Near-Earth Asteroid Research (LINEAR) Program] Grant H. Stokes, Frank Shelly, Herbert E.M. Viggh, Matthew S. Blythe, and Joseph S. Stuart * [https://web.archive.org/web/20040513230213/http://neo.jpl.nasa.gov/stats/ Near Earth Object program – discovery statistics], Jet Propulsion Laboratory

{{Comets|nonobject=yes}} {{Planetary defense}}

[[Category:1996 establishments in the United States]] [[Category:Discoveries by LINEAR| ]] [[Category:Near-Earth object tracking]]