The Infrared Astronomical Satellite (
Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first
space telescope to perform a
survey of the entire
night sky at
infrared wavelengths. Launched on 25 January 1983,
its mission lasted ten months.
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.
Support for the processing and analysis of data from IRAS was contributed from the
Infrared Processing and Analysis Center at the
California Institute of Technology. Currently, the
Infrared Science Archive at IPAC holds the IRAS archive.
The success of IRAS led to interest in the 1985
Infrared 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 the
Spitzer Space Telescope
The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...
, launched in 2003. The success of early infrared space astronomy led to further missions, such as the
Infrared Space Observatory (1990s) and the
Hubble Space Telescope NICMOS
The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) is a scientific instrument for infrared astronomy, installed on the Hubble Space Telescope (HST), operating from 1997 to 1999, and from 2002 to 2008. Images produced by NICMOS contain ...
instrument.
Mission
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 be
starburst galaxies, still enduring their
star-formation stage. Many other sources are normal stars with disks of dust around them, possibly the early stage of
planetary system
A planetary system is a set of gravitationally
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interacti ...
formation. New discoveries included a dust disk around
Vega and the first images of the
Milky Way core.
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, of
superfluid helium kept the telescope at a temperature of , keeping the satellite cool by
evaporation
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidi ...
. IRAS was the first use of superfluids in space. 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, including
John K. Davies and
Simon F. Green
Simon F. Green (born 1959) is an astronomer. He is a Senior Lecturer in Planetary and Space Science at the Open University. He specializes in the study of asteroids and trans-Neptunian objects, and for a long time worked with the IRAS satellite t ...
, which searched the rejected sources for moving objects. This led to the discovery of three
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
s, including
3200 Phaethon
3200 Phaethon (previously sometimes spelled Phaeton), provisional designation , is an active Apollo asteroid with an orbit that brings it closer to the Sun than any other named asteroid (though there are numerous unnamed asteroids with smaller ...
(an
Apollo asteroid and the parent body of the
Geminid
The Geminids are a prolific meteor shower caused by the object 3200 Phaethon, which is thought to be a Palladian asteroid with a " rock comet" orbit. This would make the Geminids, together with the Quadrantids, the only major meteor showers ...
meteor shower
A meteor shower is a celestial event in which a number of meteors are observed to radiate, or originate, from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extre ...
), six
comets, and a huge dust trail associated with comet
10P/Tempel
10P/Tempel, also known as Tempel 2, is a periodic Jupiter-family comet with a 5 year orbital period. It was discovered on July 4, 1873 by Wilhelm Tempel. The next perihelion passage is 24 March 2021 when the comet will have a solar elongation ...
. The comets included
126P/IRAS,
161P/Hartley–IRAS, and
comet 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.
Discoveries
Overall, over a quarter million discrete targets were observed during its operations, both inside and beyond the
Solar System.
In addition, new objects were discovered including asteroids and comets.
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 planet
Jupiter and possibly so close to
Earth that it would be part of this solar system". Further analysis revealed that, of several unidentified objects, nine were distant galaxies and the tenth was "
intergalactic cirrus".
None were found to be Solar System bodies.
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 discovered
planetary disks around these stars.
IRAS discovered six comets, out of total of 22 discoveries and recoveries of all comets that year.
This was a lot for this period, before the launch of
SOHO in 1995, which would allow the discovery of many more comets in the next decade (it would detect 1000 comets in ten years).
Asteroid discoveries
Later surveys
Several infrared space telescopes have continued and greatly expanded the study of the infrared Universe, such as the
Infrared Space Observatory launched in 1995, the
Spitzer Space Telescope
The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...
launched in 2003, and the
Akari Space Telescope launched in 2006.
A next generation of infrared space telescopes began when NASA's
Wide-field Infrared Survey Explorer launched on 14 December 2009 aboard a
Delta II rocket from
Vandenberg 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 dubbed
NEOWISE beginning in October 2010 after its coolant supply ran out.
A planned mission is NASA's
Near-Earth Object Surveillance Mission
NEO Surveyor, formerly called Near-Earth Object Camera (NEOCam), then NEO Surveillance Mission, is a planned space-based infrared telescope designed to survey the Solar System for potentially hazardous asteroids.[GGSE-4 The Gravity Gradient Stabilization Experiment (GGSE-4) was a technology satellite launched in 1967. This was ostensibly the GGSE-1, fourth in a series that developed designs and deployment techniques later applied to the NOSS/Whitecloud reconnaissa ...]
) of 1967, another un-deorbited satellite left aloft; the 14.7-kilometer per second pass 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. 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.
See also
*
GGSE-4 The Gravity Gradient Stabilization Experiment (GGSE-4) was a technology satellite launched in 1967. This was ostensibly the GGSE-1, fourth in a series that developed designs and deployment techniques later applied to the NOSS/Whitecloud reconnaissa ...
*
Diffuse Infrared Background Experiment, an infrared sky survey on
COBE (1989)
*
Infrared astronomy
*
List of asteroid-discovering observatories
*
List of largest infrared telescopes
*
*
:IRAS catalogue objects
References
Bibliography
*
External links
IRAS websiteby Caltech
by the Planetary Science Institute
IRAS surveyat WikiSky.org
{{Authority control
Asteroid surveys
Astronomical surveys
*
Minor-planet discovering observatories
Infrared telescopes
Space telescopes
Spacecraft launched in 1983
Satellites of the Netherlands