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IRAS

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This article is about the space telescope. For other uses, seeIRAS (disambiguation).
Infrared Astronomical Satellite / Infrarood Astronomische Satelliet
Infrared Astronomical Satellite in space simulator at JPL
Mission typeInfraredspace observatory
Operator
COSPAR ID1983-004AEdit this at Wikidata
SATCATno.13777
Websiteirsa.ipac.caltech.edu/Missions/iras.html
Mission durationFinal: 9 months, 26 days
Spacecraft properties
Manufacturer
Launch mass1,083 kg (2,388 lb)
Dimensions3.60 × 3.24 × 2.05 m (11.8 × 10.6 × 6.7 ft)[1]
Start of mission
Launch date25 January 1983, 21:17(1983-01-25UTC21:17)UTC[3]
RocketDelta 3910
Launch siteVandenbergSLC-2W
Entered service9 February 1983[2]
End of mission
DisposalDecommissioned
Deactivated21 November 1983(1983-11-22)[3]
Orbital parameters
Reference systemGeocentric
RegimeSun-synchronous
Semi-major axis7,270.69 km (4,517.80 mi)
Eccentricity0.001857
Perigee altitude879.05 km (546.22 mi)
Apogee altitude906.05 km (562.99 mi)
Inclination98.95 deg
Period102.8 min
Mean motion14.00 rev/day
Epoch19 November 2016, 04:15:30UTC[4]
Main telescope
TypeRitchey–Chrétien[5]
Diameter57 cm (22 in)[5]
Focal length545 cm (215 in),f/9.56[5]
Collecting area2,019 cm2(312.9 sq in)[5]
WavelengthsLong-wavelength to far-infrared

TheInfrared Astronomical Satellite(Dutch:Infrarood Astronomische Satelliet) (IRAS) was the firstspace telescopeto perform asurveyof the entirenight skyatinfraredwavelengths.[6]Launched on 25 January 1983,[3]its mission lasted ten months.[7]The telescope was a joint project of the United States (NASA), the Netherlands (NIVR), and the United Kingdom (SERC). Over 250,000 infrared sources were observed at 12, 25, 60, and 100 micrometer wavelengths.[7]

Support for the processing and analysis of data from IRAS was contributed from theInfrared Processing and Analysis Centerat theCalifornia Institute of Technology.Currently, theInfrared Science Archiveat IPAC holds the IRAS archive.[8][9]

The success of IRAS led to interest in the 1985Infrared Telescope(IRT) mission on the Space Shuttle, and the planned Shuttle Infrared Telescope Facility which eventually transformed into the Space Infrared Telescope Facility, SIRTF, which in turn was developed into theSpitzer Space Telescope,launched in 2003.[10]The success of early infrared space astronomy led to further missions, such as theInfrared Space Observatory(1990s) and theHubble Space Telescope'sNICMOSinstrument.

Mission[edit]

Launch of IRAS in 1983
False color image ofcomet IRAS–Araki–Alcockby IRAS
Infrared all-sky survey by IRAS

IRAS was the first observatory to perform an all-sky survey at infrared wavelengths. It mapped 96% of the sky four times, at 12, 25, 60 and 100 micrometers, with resolutions ranging from 30 arcseconds at 12 micrometers to 2 arcminutes at 100 micrometers. It discovered about 350,000 sources, many of which are still awaiting identification. About 75,000 of those are believed to bestarburst galaxies,still enduring theirstar-formationstage. Many other sources are normal stars with disks of dust around them, possibly the early stage ofplanetary systemformation. New discoveries included a dust disk aroundVegaand the first images of theMilky Way'score.

IRAS's life, like that of most infrared satellites that followed, was limited by its cooling system. To effectively work in the infrared domain, a telescope must be cooled to cryogenic temperatures. In IRAS's case, 73 kilograms (161 lb) ofsuperfluidheliumkept the telescope at a temperature of 2K(−271°C;−456°F), keeping the satellite cool byevaporation.IRAS was the first use of superfluids in space.[11]The on-board supply of liquid helium was depleted after 10 months on 21 November 1983, causing the telescope temperature to rise, preventing further observations. The spacecraft continues to orbit the Earth.

IRAS was designed to catalog fixed sources, so it scanned the same region of sky several times. Jack Meadows led a team at Leicester University, includingJohn K. DaviesandSimon F. Green,which searched the rejected sources for moving objects. This led to the discovery of threeasteroids,including3200 Phaethon(anApollo asteroidand the parent body of theGeminidmeteor shower), sixcomets,and a huge dust trail associated with comet10P/Tempel.The comets included126P/IRAS,161P/Hartley–IRAS,andcomet IRAS–Araki–Alcock(C/1983 H1), which made a close approach to the Earth in 1983. Out of the six comets IRAS found, four were long period and two were short period comets.[7]

Discoveries[edit]

IRAS made its observations from Earth orbit in 1983

Overall, over a quarter million discrete targets were observed during its operations, both inside and beyond theSolar System.[7]In addition, new objects were discovered including asteroids and comets.[7] The observatory made headlines briefly with the announcement on 10 December 1983 of the discovery of an "unknown object" at first described as "possibly as large as the giant planetJupiterand possibly so close toEarththat it would be part of this solar system ".[12][13]Further analysis revealed that, of several unidentified objects, nine were distant galaxies and the tenth was "intergalactic cirrus".[14]None were found to be Solar System bodies.[14][15]

During its mission, IRAS (and later the Spitzer Space Telescope) detected odd infrared signatures around several stars. This led to the systems being targeted by the Hubble Space Telescope's NICMOS instrument between 1999 and 2006, but nothing was detected. In 2014, using new image processing techniques on the Hubble data, researchers discoveredplanetary disksaround these stars.[16]

IRAS discovered six comets, out of total of 22 discoveries and recoveries of all comets that year.[7][17]This was a lot for this period, before the launch ofSOHOin 1995, which would allow the discovery of many more comets in the next decade (it would detect 1000 comets in ten years).[18]

Asteroid discoveries[edit]

Minor planetsdiscovered: 4 [19]
3200 Phaethon 11 October 1983 list
3728 IRAS 23 August 1983 list
(10714) 1983 QG 31 August 1983 list
(100004) 1983 VA 1 November 1983 list

Later surveys[edit]

Several infrared space telescopes have continued and greatly expanded the study of the infrared Universe, such as theInfrared Space Observatorylaunched in 1995, theSpitzer Space Telescopelaunched in 2003, and theAkariSpace Telescope launched in 2006.

A next generation of infrared space telescopes began when NASA'sWide-field Infrared Survey Explorerlaunched on 14 December 2009 aboard aDelta IIrocket fromVandenberg Air Force Base.Known as WISE, the telescope provided results hundreds of times more sensitive than IRAS at the shorter wavelengths; it also had an extended mission dubbedNEOWISEbeginning in October 2010 after its coolant supply ran out.

A planned mission is NASA'sNear-Earth Object Surveillance Mission(NEOSM), which is a successor to the NEOWISE mission.

2020 near-miss[edit]

On 29 January 2020, 23:39:35 UTC,[20]IRAS was expected to pass as closely as 12 meters[21]from the U.S. Air Force's Gravity Gradient Stabilization Experiment (GGSE-4) of 1967, another un-deorbited satellite left aloft; the 14.7-kilometer per second pass[22]had an estimated risk of collision of 5%. Further complications arose from the fact that GGSE-4 was outfitted with an 18 meter long stabilization boom that was in an unknown orientation and may have struck the satellite even if the spacecraft's main body did not.[23]Initial observations from amateur astronomers seemed to indicate that both satellites had survived the pass, with the California-based debris tracking organization LeoLabs later confirming that they had detected no new tracked debris following the incident.[24][25]

See also[edit]

References[edit]

  1. ^Beichman 1988,p. II-1.
  2. ^Neugebauer, G.; Habing, H. J.; van Duinen, R.; Aumann, H. H.; Baud, B.; et al. (March 1984)."The Infrared Astronomical Satellite (IRAS) mission"(PDF).Astrophysical Journal.278:L1–L6.Bibcode:1984ApJ...278L...1N.doi:10.1086/184209.hdl:1887/6453.
  3. ^abc"Infrared Astronomical Satellite".NASA.Retrieved19 November2016.
  4. ^"IRAS - Orbit".Heavens-Above.19 November 2016.Retrieved19 November2016.
  5. ^abcdBeichman 1988,p. II-8.
  6. ^Beichman 1988,p. I-1.
  7. ^abcdefSchmadel, Lutz D. (2007). "(3728) Iras".Dictionary of Minor Planet Names.Springer Berlin Heidelberg.p.315.doi:10.1007/978-3-540-29925-7_3725.ISBN978-3-540-00238-3.
  8. ^"Infrared Astronomical Satellite".Infrared Processing and Analysis Center.Caltech.Archived fromthe originalon 6 June 2016.Retrieved19 November2016.
  9. ^"Infrared Astronomical Satellite (IRAS)".NASA/IPAC Infrared Science Archive.Caltech.Retrieved19 November2016.
  10. ^"Early History".Spitzer Space Telescope. NASA. Archived fromthe originalon 2 August 2020.Retrieved30 November2016.
  11. ^Rowan-Robinson, Michael(1993).Ripples in the Cosmos.W. H. Freeman and Company. p. 75.ISBN0-7167-4503-8.
  12. ^O'Toole, Thomas (30 December 1983)."Mystery Heavenly Body Discovered".The Washington Post.p. A1. Archived fromthe originalon 1 February 2010.
  13. ^"Mystery heavenly body found close to Earth".The Gazette.Washington Post.30 December 1983. p. A-1.Retrieved16 October2012.
  14. ^abChester, Thomas J. (5 May 1998)."No Tenth Planet Yet From IRAS".Caltech. Archived fromthe originalon 2 February 2010.
  15. ^Plait, Phil(17 November 2010)."The Planet X Saga: Science".Bad Astronomy.Retrieved5 March2011.
  16. ^Harrington, J. D.; Villard, Ray (24 April 2014)."Astronomical Forensics Uncover Planetary Disks in NASA's Hubble Archive".NASA. NASA Release 14-114.Retrieved30 November2016.
  17. ^Marsden, B. G. (1986)."1986QJRAS..27..102M Page 102".Quarterly Journal of the Royal Astronomical Society.27:102.Bibcode:1986QJRAS..27..102M.Retrieved2019-09-30.
  18. ^"NASA - History's Greatest Comet Hunter Discovers 1,000th Comet".nasa.gov.Retrieved2019-09-30.
  19. ^"Minor Planet Discoverers".Minor Planet Center.4 September 2016.Retrieved11 November2016.
  20. ^@LeoLabs_Space (29 January 2020)."Our latest data on the IRAS / GGSE 4 event"(Tweet) – viaTwitter.
  21. ^@LeoLabs_Space (29 January 2020)."Our latest update this morning for IRAS / GGSE 4"(Tweet) – viaTwitter.
  22. ^"2 satellites will narrowly avoid colliding at 32,800 MPH over Pittsburgh on Wednesday".Space.28 January 2020.
  23. ^@LeoLabs_Space (29 January 2020)."Adjusted calculations for larger object size"(Tweet) – viaTwitter.
  24. ^@juliancd38 (29 January 2020)."Trails of both IRAS and GGSE4 continue unimpeded after intersection"(Tweet) – viaTwitter.
  25. ^@LeoLabs_Space (29 January 2020)."Latest data following the event shows no evidence of new debris"(Tweet) – viaTwitter.

Bibliography[edit]

External links[edit]

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