Spitzer Space Telescope
Encyclopedia
The Spitzer Space Telescope (SST), formerly the Space Infrared Telescope Facility (SIRTF) is an infrared
space observatory
launched in 2003. It is the fourth and final of the NASA
Great Observatories program
.
The planned mission period was to be 2.5 years with a pre-launch expectation that the mission could extend to five or slightly more years until the onboard liquid helium
supply was exhausted. This occurred on 15 May 2009. Without liquid helium to cool the telescope to the very cold temperatures needed to operate, most instruments are no longer usable. However, the two shortest wavelength modules of the IRAC camera are still operable with the same sensitivity as before the cryogen was exhausted, and will continue to be used in the Spitzer Warm Mission.
In keeping with NASA tradition, the telescope was renamed after successful demonstration of operation, on December 18, 2003. Unlike most telescope
s which are named after famous deceased astronomers by a board of scientists, the name for SIRTF was obtained from a contest open to the general public.
The contest led to the telescope being named in honor of Lyman Spitzer
, one of the 20th century's great scientists. Though he was not the first to propose the idea of the space telescope (Hermann Oberth
being the first, in Wege zur Raumschiffahrt, 1929, and also in Die Rakete zu den Planetenräumen, 1923), Spitzer
wrote a 1946 report for RAND
describing the advantages of an extraterrestrial observatory and how it could be realized with available (or upcoming) technology. He has been cited for his pioneering contributions to rocket
ry and astronomy
, as well as "his vision and leadership in articulating the advantages and benefits to be realized from the Space Telescope Program."
The Spitzer was launched from Cape Canaveral Air Force Station
, on a Delta II 7920H ELV rocket, Monday, 25 August 2003 at 13:35:39 UTC-5
(EDT).
It follows a rather unusual orbit, heliocentric
instead of geocentric
, trailing and drifting away from Earth's orbit at approximately 0.1 astronomical unit
per year (a so-called "earth-trailing" orbit). The primary mirror
is 85 centimetres (33.5 in) in diameter, f/12
and made of beryllium
and was cooled to 5.5 kelvin (-449.8 °F). The satellite
contains three instruments that allowed it to perform imaging and photometry
from 3 to 180 micrometers, spectroscopy
from 5 to 40 micrometers, and spectrophotometry
from 5 to 100 micrometers.
above the obscuring effects of Earth's atmosphere.
In 1979, a National Research Council of the National Academy of Sciences
report, A Strategy for Space Astronomy and Astrophysics for the 1980s, identified a Space Infrared Telescope Facility (SIRTF) as "one of two major astrophysics facilities [to be developed] for Spacelab
", a Shuttle-borne platform. Anticipating the major results from an upcoming Explorer satellite and from the Shuttle mission, the report also favored the "study and development of ... long-duration spaceflights of infrared telescopes cooled to cryogenic temperatures."
The launch in January 1983 of the Infrared Astronomical Satellite, jointly developed by the United States, the Netherlands, and the United Kingdom, to conduct the first infrared survey of the sky, whetted the appetites of scientists worldwide for follow-up space missions capitalizing on the rapid improvements in infrared detector technology.
Earlier infrared observations had been made by both space-based and ground-based observatories
. Ground-based observatories have the drawback that at infrared wavelength
s or frequencies
, both the Earth's atmosphere
and the telescope itself will radiate (glow) strongly. Additionally, the atmosphere is opaque at most infrared wavelengths. This necessitates lengthy exposure times and greatly decreases the ability to detect faint objects. It could be compared to trying to observe the stars at noon. Previous space-based satellites (such as IRAS
, the Infrared Astronomical Satellite, and ISO
, the Infrared Space Observatory) were operational during the 1980s and 1990s and great advances in astronomical technology have been made since then.
Most of the early concepts envisioned repeated flights aboard the NASA Space Shuttle.
This approach was developed in an era when the Shuttle program was expected to support weekly flights of up to 30 days duration.
A May 1983 NASA proposal described SIRTF as a Shuttle-attached mission, with an evolving scientific instrument payload.
Several flights were anticipated with a probable transition into a more extended mode of operation, possibly in association with a future space platform or space station.
SIRTF would be a 1-meter class, cryogenically cooled, multi-user facility consisting of a telescope and associated focal plane instruments.
It would be launched on the Space Shuttle and remain attached to the Shuttle as a Spacelab payload during astronomical observations, after which it would be returned to Earth for refurbishment prior to re-flight.
The first flight was expected to occur about 1990, with the succeeding flights anticipated beginning approximately one year later.
However, the Spacelab-2 flight aboard STS-51-F
showed that the Shuttle environment was poorly suited to an onboard infrared telescope due to contamination from the relatively "dirty" vacuum associated with the orbiters.
By September 1983 NASA was considering the "possibility of a long duration [free-flyer] SIRTF mission".
Spitzer is the only one of the Great Observatories not launched by the Space Shuttle
, which had been originally intended.
However after the 1986 Challenger disaster, the Centaur
LH2/LOX
upper stage, which would have been required to place it in its final orbit, was banned from Shuttle use.
The mission underwent a series of redesigns during the 1990s, primarily due to budget considerations. This resulted in a much smaller but still fully capable mission which could use the smaller Delta II expendable launch vehicle.
One of the most important advances of this redesign was an Earth-trailing orbit.
Cryogenic satellites that require liquid helium (LHe, T ≈ 4 K) temperatures in near-Earth orbit are typically exposed to a large heat load from the Earth, and consequently entail large usage of LHe coolant, which then tends to dominate the total payload mass and limits mission life.
Placing the satellite in solar orbit far from Earth allowed innovative passive cooling such as the sun shield, against the single remaining major heat source to drastically reduce the total mass of helium needed, resulting in an overall smaller lighter payload, with major cost savings.
This orbit also simplifies telescope pointing, but does require the Deep Space Network
for communications.
The primary instrument package (telescope and cryogenic chamber) was developed by Ball Aerospace & Technologies Corp., in Boulder, CO. The individual instruments were developed jointly by industrial, academic, and government institutions, the principals being Cornell, the University of Arizona, the Smithsonian Astrophysical Observatory, Ball Aerospace, and Goddard Spaceflight Center. The infrared detectors were developed by Raytheon in Goleta, California. Raytheon used indium antimonide and a doped silicon detector in the creation of the infrared detectors. It is stated that these detectors are 100 times more sensitive than what was once available in the beginning of the project during the 1980's. The spacecraft was built by Lockheed Martin
. The mission is operated and managed by the Jet Propulsion Laboratory
and the Spitzer Science Center, located on the Caltech campus in Pasadena, California.
As an example of data from the different instruments, the nebula Henize 206
was imaged in 2004, allowing comparison of images from each device.
The first images taken by SST were designed to show off the abilities of the telescope and showed a glowing stellar nursery; a big swirling, dusty galaxy
; a disc of planet-forming debris; and organic material in the distant universe. Since then, many monthly press releases have highlighted Spitzer's capabilities, as the NASA and ESA images do for the Hubble Space Telescope
.
As one of its most noteworthy observations, in 2005, SST became the first telescope to directly capture the light from extrasolar planet
s, namely the "hot Jupiters" HD 209458b and TrES-1. (It did not resolve that light into actual images though.) This was the first time extrasolar planets had actually been visually seen; earlier observations had been indirectly made by drawing conclusions from behaviors of the stars the planets were orbiting. The telescope also discovered in April 2005 that Cohen-kuhi Tau/4
had a planetary disk that was vastly younger and contained less mass than previously theorized, leading to new understandings of how planets are formed.
While some time on the telescope is reserved for participating institutions and crucial projects, astronomers around the world also have the opportunity to submit proposals for observing time. Important targets include forming stars (young stellar object
s, or YSOs), planets, and other galaxies. Images are freely available for educational and journalistic purposes.
In 2004, it was reported that Spitzer had spotted a faintly glowing body that may be the youngest star ever seen. The telescope was trained on a core of gas and dust known as L1014
which had previously appeared completely dark to ground-based observatories and to ISO (Infrared Space Observatory
), a predecessor to Spitzer. The advanced technology of Spitzer revealed a bright red hot spot in the middle of L1014.
Scientists from the University of Texas at Austin
, who discovered the object, believe the hot spot to be an example of early star development, with the young star collecting gas and dust from the cloud around it. Early speculation about the hot spot was that it might have been the faint light of another core that lies 10 times further from Earth but along the same line of sight as L1014. Follow-up observation from ground-based near-infrared observatories detected a faint fan-shaped glow in the same location as the object found by Spitzer. That glow is too feeble to have come from the more distant core, leading to the conclusion that the object is located within L1014. (Young et al., 2004)
In 2005, astronomers from the University of Wisconsin
at Madison
and Whitewater determined, on the basis of 400 hours of observation on the Spitzer Space Telescope, that the Milky Way Galaxy has a more substantial bar structure across its core than previously recognized.
Also in 2005, astronomers Alexander Kashlinsky
and John Mather
of NASA's Goddard Space Flight Center
reported that one of Spitzer's earliest images may have captured the light of the first stars in the universe. An image of a quasar
in the Draco
constellation
, intended only to help calibrate the telescope, was found to contain an infrared glow after the light of known objects was removed. Kashlinsky and Mather are convinced that the numerous blobs in this glow are the light of stars that formed as early as 100 million years after the big bang
, red shift
ed by cosmic expansion.
In March 2006, astronomers reported an 80-light-year-long nebula near the center of the Milky Way Galaxy, the Double Helix Nebula
, which is, as the name implies, twisted into a double spiral shape. This is thought to be evidence of massive magnetic fields generated by the gas disc orbiting the supermassive black hole
at the galaxy's center, 300 light years from the nebula and 25,000 light years from Earth. This nebula was discovered by the Spitzer Space Telescope, and published in the magazine Nature on March 16, 2006.
In May 2007, astronomers successfully mapped the atmospheric temperature of HD 189733 b
, thus obtaining the first map of some kind of an extrasolar planet.
Since September 2006 the telescope participates in a series of surveys called the Gould Belt Survey
, observing the Gould's Belt
region in multiple wavelengths. The first set of observations by the Spitzer Space Telescope were completed from September 21, 2006 through September 27. Resulting from these observations, the team of astronomers led by Dr. Robert Gutermuth, of the Harvard-Smithsonian Center for Astrophysics
reported the discovery of Serpens South
, a cluster of 50 young stars in the Serpens
constellation.
In August 2009, the telescope found evidence of a high-speed collision between two burgeoning planets orbiting a young star.
In October 2009, astronomers Anne J. Verbiscer, Michael F. Skrutskie, and Douglas P. Hamilton published findings of the "Phoebe ring" of Saturn
, which was found with the telescope; the ring is a huge, tenuous disc of material extending from 128 to 207 times the radius of Saturn.
MIPSGAL is a similar survey covering 278° of the galactic disk at longer wavelengths.
On June 3, 2008, scientists unveiled the largest, most detailed infra-red portrait of the Milky Way
, created by stitching together more than 800,000 snapshots, at the 212th meeting of the American Astronomical Society
in St.Louis, Missouri
.
This composite survey is now viewable with the GLIMPSE/MIPSGAL Viewer.
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
space observatory
Space observatory
A space observatory is any instrument in outer space which is used for observation of distant planets, galaxies, and other outer space objects...
launched in 2003. It is the fourth and final of the NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
Great Observatories program
Great Observatories program
NASA's series of Great Observatories satellites are four large, powerful space-based telescopes. Each of the Great Observatories has had a similar size and cost at program outset, and each has made a substantial contribution to astronomy...
.
The planned mission period was to be 2.5 years with a pre-launch expectation that the mission could extend to five or slightly more years until the onboard liquid helium
Liquid helium
Helium exists in liquid form only at extremely low temperatures. The boiling point and critical point depend on the isotope of the helium; see the table below for values. The density of liquid helium-4 at its boiling point and 1 atmosphere is approximately 0.125 g/mL Helium-4 was first liquefied...
supply was exhausted. This occurred on 15 May 2009. Without liquid helium to cool the telescope to the very cold temperatures needed to operate, most instruments are no longer usable. However, the two shortest wavelength modules of the IRAC camera are still operable with the same sensitivity as before the cryogen was exhausted, and will continue to be used in the Spitzer Warm Mission.
In keeping with NASA tradition, the telescope was renamed after successful demonstration of operation, on December 18, 2003. Unlike most telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
s which are named after famous deceased astronomers by a board of scientists, the name for SIRTF was obtained from a contest open to the general public.
The contest led to the telescope being named in honor of Lyman Spitzer
Lyman Spitzer
Lyman Strong Spitzer, Jr. was an American theoretical physicist and astronomer best known for his research in star formation, plasma physics, and in 1946, for conceiving the idea of telescopes operating in outer space...
, one of the 20th century's great scientists. Though he was not the first to propose the idea of the space telescope (Hermann Oberth
Hermann Oberth
Hermann Julius Oberth was an Austro-Hungarian-born German physicist and engineer. He is considered one of the founding fathers of rocketry and astronautics.- Early life :...
being the first, in Wege zur Raumschiffahrt, 1929, and also in Die Rakete zu den Planetenräumen, 1923), Spitzer
Lyman Spitzer
Lyman Strong Spitzer, Jr. was an American theoretical physicist and astronomer best known for his research in star formation, plasma physics, and in 1946, for conceiving the idea of telescopes operating in outer space...
wrote a 1946 report for RAND
RAND
RAND Corporation is a nonprofit global policy think tank first formed to offer research and analysis to the United States armed forces by Douglas Aircraft Company. It is currently financed by the U.S. government and private endowment, corporations including the healthcare industry, universities...
describing the advantages of an extraterrestrial observatory and how it could be realized with available (or upcoming) technology. He has been cited for his pioneering contributions to rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...
ry and astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
, as well as "his vision and leadership in articulating the advantages and benefits to be realized from the Space Telescope Program."
The Spitzer was launched from Cape Canaveral Air Force Station
Cape Canaveral Air Force Station
Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...
, on a Delta II 7920H ELV rocket, Monday, 25 August 2003 at 13:35:39 UTC-5
UTC-5
UTC−05:00 is an identifier for a time offset from UTC of −05.This offset is used in the Eastern Time Zone during standard time and in the Central Time Zone during Daylight Saving Time ....
(EDT).
It follows a rather unusual orbit, heliocentric
Heliocentric orbit
A heliocentric orbit is an orbit around the Sun. All planets, comets, and asteroids in our Solar System are in such orbits, as are many artificial probes and pieces of debris. The moons of planets in the Solar System, by contrast, are not in heliocentric orbits as they orbit their respective planet...
instead of geocentric
Geocentric orbit
A geocentric orbit involves any object orbiting the Earth, such as the Moon or artificial satellites. Currently there are approximately 2,465 artificial satellites orbiting the Earth and 6,216 pieces of space debris as tracked by the Goddard Space Flight Center...
, trailing and drifting away from Earth's orbit at approximately 0.1 astronomical unit
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
per year (a so-called "earth-trailing" orbit). The primary mirror
Primary mirror
A primary mirror is the principal light-gathering surface of a reflecting telescope.-Description:The primary mirror of a reflecting telescope is a spherical or parabolic shaped disks of polished reflective metal , or in later telescopes, glass or other material coated with a reflective layer...
is 85 centimetres (33.5 in) in diameter, f/12
F-number
In optics, the f-number of an optical system expresses the diameter of the entrance pupil in terms of the focal length of the lens; in simpler terms, the f-number is the focal length divided by the "effective" aperture diameter...
and made of beryllium
Beryllium
Beryllium is the chemical element with the symbol Be and atomic number 4. It is a divalent element which occurs naturally only in combination with other elements in minerals. Notable gemstones which contain beryllium include beryl and chrysoberyl...
and was cooled to 5.5 kelvin (-449.8 °F). The satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
contains three instruments that allowed it to perform imaging and photometry
Photometry (astronomy)
Photometry is a technique of astronomy concerned with measuring the flux, or intensity of an astronomical object's electromagnetic radiation...
from 3 to 180 micrometers, spectroscopy
Spectroscopy
Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...
from 5 to 40 micrometers, and spectrophotometry
Spectrophotometry
In chemistry, spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength...
from 5 to 100 micrometers.
History
By the early 1970s, astronomers began to consider the possibility of placing an infrared telescopeInfrared telescope
An infrared telescope is a telescope that uses infrared light to detect celestial bodies.Infrared light is one of several types of radiation present in the electromagnetic spectrum....
above the obscuring effects of Earth's atmosphere.
In 1979, a National Research Council of the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
report, A Strategy for Space Astronomy and Astrophysics for the 1980s, identified a Space Infrared Telescope Facility (SIRTF) as "one of two major astrophysics facilities [to be developed] for Spacelab
Spacelab
Spacelab was a reusable laboratory used on certain spaceflights flown by the Space Shuttle. The laboratory consisted of multiple components, including a pressurized module, an unpressurized carrier and other related hardware housed in the Shuttle's cargo bay...
", a Shuttle-borne platform. Anticipating the major results from an upcoming Explorer satellite and from the Shuttle mission, the report also favored the "study and development of ... long-duration spaceflights of infrared telescopes cooled to cryogenic temperatures."
The launch in January 1983 of the Infrared Astronomical Satellite, jointly developed by the United States, the Netherlands, and the United Kingdom, to conduct the first infrared survey of the sky, whetted the appetites of scientists worldwide for follow-up space missions capitalizing on the rapid improvements in infrared detector technology.
Earlier infrared observations had been made by both space-based and ground-based observatories
Observatory
An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed...
. Ground-based observatories have the drawback that at infrared wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
s or frequencies
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
, both the Earth's atmosphere
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
and the telescope itself will radiate (glow) strongly. Additionally, the atmosphere is opaque at most infrared wavelengths. This necessitates lengthy exposure times and greatly decreases the ability to detect faint objects. It could be compared to trying to observe the stars at noon. Previous space-based satellites (such as IRAS
IRAS
The Infrared Astronomical Satellite was the first-ever space-based observatory to perform a survey of the entire sky at infrared wavelengths....
, the Infrared Astronomical Satellite, and ISO
Infrared Space Observatory
The Infrared Space Observatory was a space telescope for infrared light designed and operated by the European Space Agency , in cooperation with ISAS and NASA...
, the Infrared Space Observatory) were operational during the 1980s and 1990s and great advances in astronomical technology have been made since then.
Most of the early concepts envisioned repeated flights aboard the NASA Space Shuttle.
This approach was developed in an era when the Shuttle program was expected to support weekly flights of up to 30 days duration.
A May 1983 NASA proposal described SIRTF as a Shuttle-attached mission, with an evolving scientific instrument payload.
Several flights were anticipated with a probable transition into a more extended mode of operation, possibly in association with a future space platform or space station.
SIRTF would be a 1-meter class, cryogenically cooled, multi-user facility consisting of a telescope and associated focal plane instruments.
It would be launched on the Space Shuttle and remain attached to the Shuttle as a Spacelab payload during astronomical observations, after which it would be returned to Earth for refurbishment prior to re-flight.
The first flight was expected to occur about 1990, with the succeeding flights anticipated beginning approximately one year later.
However, the Spacelab-2 flight aboard STS-51-F
STS-51-F
STS-51-F was the nineteenth flight of NASA's Space Shuttle program, and the eighth flight of Space Shuttle Challenger...
showed that the Shuttle environment was poorly suited to an onboard infrared telescope due to contamination from the relatively "dirty" vacuum associated with the orbiters.
By September 1983 NASA was considering the "possibility of a long duration [free-flyer] SIRTF mission".
Spitzer is the only one of the Great Observatories not launched by the Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
, which had been originally intended.
However after the 1986 Challenger disaster, the Centaur
Centaur (rocket stage)
Centaur is a rocket stage designed for use as the upper stage of space launch vehicles. Centaur boosts its satellite payload to geosynchronous orbit or, in the case of an interplanetary space probe, to or near to escape velocity...
LH2/LOX
Lox
Lox is salmon fillet that has been cured. In its most popular form, it is thinly sliced—less than in thickness—and, typically, served on a bagel, often with cream cheese, onion, tomato, cucumber and capers...
upper stage, which would have been required to place it in its final orbit, was banned from Shuttle use.
The mission underwent a series of redesigns during the 1990s, primarily due to budget considerations. This resulted in a much smaller but still fully capable mission which could use the smaller Delta II expendable launch vehicle.
One of the most important advances of this redesign was an Earth-trailing orbit.
Cryogenic satellites that require liquid helium (LHe, T ≈ 4 K) temperatures in near-Earth orbit are typically exposed to a large heat load from the Earth, and consequently entail large usage of LHe coolant, which then tends to dominate the total payload mass and limits mission life.
Placing the satellite in solar orbit far from Earth allowed innovative passive cooling such as the sun shield, against the single remaining major heat source to drastically reduce the total mass of helium needed, resulting in an overall smaller lighter payload, with major cost savings.
This orbit also simplifies telescope pointing, but does require the Deep Space Network
Deep Space Network
The Deep Space Network, or DSN, is a world-wide network of large antennas and communication facilities that supports interplanetary spacecraft missions. It also performs radio and radar astronomy observations for the exploration of the solar system and the universe, and supports selected...
for communications.
The primary instrument package (telescope and cryogenic chamber) was developed by Ball Aerospace & Technologies Corp., in Boulder, CO. The individual instruments were developed jointly by industrial, academic, and government institutions, the principals being Cornell, the University of Arizona, the Smithsonian Astrophysical Observatory, Ball Aerospace, and Goddard Spaceflight Center. The infrared detectors were developed by Raytheon in Goleta, California. Raytheon used indium antimonide and a doped silicon detector in the creation of the infrared detectors. It is stated that these detectors are 100 times more sensitive than what was once available in the beginning of the project during the 1980's. The spacecraft was built by Lockheed Martin
Lockheed Martin
Lockheed Martin is an American global aerospace, defense, security, and advanced technology company with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It is headquartered in Bethesda, Maryland, in the Washington Metropolitan Area....
. The mission is operated and managed by the Jet Propulsion Laboratory
Jet Propulsion Laboratory
Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...
and the Spitzer Science Center, located on the Caltech campus in Pasadena, California.
Instruments
Spitzer carries three instruments on-board:- IRAC (Infrared Array Camera), an infrared camera which operates simultaneously on four wavelengths (3.6 µm, 4.5 µm, 5.8 µm and 8 µm). Each module uses a 256 × 256 pixel detector—the short wavelength pair use indium antimonide technology, the long wavelength pair use arsenic-doped silicon impurity band conduction technology. The two shorter wavelength bands (3.6 µm & 4.5 µm) for this instrument remain productive after LHe depletion in the spring of 2009, at the telescope equilibrium temperature of around 30 K, so IRAC continues to operate as the "Spitzer Warm Mission".
- IRS (Infrared Spectrograph), an infrared spectrometer with four sub-modules which operate at the wavelengths 5.3-14 µm (low resolution), 10-19.5 µm (high resolution), 14-40 µm (low resolution), and 19-37 µm (high resolution). Each module uses a 128x128 pixel detector—the short wavelength pair use arsenic-doped silicon blocked impurity band technology, the long wavelength pair use antimony-doped silicon blocked impurity band technology.
- MIPS (Multiband Imaging Photometer for Spitzer), three detector arrays in the far infrared (128 × 128 pixels at 24 µm, 32 × 32 pixels at 70 µm, 2 × 20 pixels at 160 µm). The 24 µm detector is identical to one of the IRS short wavelength modules. The 70 µm detector uses gallium-doped germanium technology, and the 160 µm detector also uses gallium-doped germanium, but with mechanical stress added to each pixel to lower the bandgap and extend sensitivity to this long wavelength.
As an example of data from the different instruments, the nebula Henize 206
Henize 206
Henize 206[p] is a nebula in the Large Magellanic Cloud.This luminous cloud of gas and dust houses a cluster of newborn stars. Although Henize 206 was first catalogued in the 1950s, it was reported in NASA press releases in March 2004, for showing several example images generated from the various...
was imaged in 2004, allowing comparison of images from each device.
Results
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
; a disc of planet-forming debris; and organic material in the distant universe. Since then, many monthly press releases have highlighted Spitzer's capabilities, as the NASA and ESA images do for the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
.
As one of its most noteworthy observations, in 2005, SST became the first telescope to directly capture the light from extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
s, namely the "hot Jupiters" HD 209458b and TrES-1. (It did not resolve that light into actual images though.) This was the first time extrasolar planets had actually been visually seen; earlier observations had been indirectly made by drawing conclusions from behaviors of the stars the planets were orbiting. The telescope also discovered in April 2005 that Cohen-kuhi Tau/4
Cohen-kuhi Tau/4
Distance~420 lyCoKu Tau/4 is a pre-main-sequence binary T Tauri star system in the constellation Taurus. The stars are surrounded by a circumbinary disc with a central cavity of radius 10 astronomical units...
had a planetary disk that was vastly younger and contained less mass than previously theorized, leading to new understandings of how planets are formed.
Young stellar object
Young stellar object denotes a star in its early stage of evolution.This class consists of two groups of objects: protostars and pre–main sequence stars. Sometimes they are divided by mass - massive YSO , intermediate mass YSO and brown dwarfs....
s, or YSOs), planets, and other galaxies. Images are freely available for educational and journalistic purposes.
In 2004, it was reported that Spitzer had spotted a faintly glowing body that may be the youngest star ever seen. The telescope was trained on a core of gas and dust known as L1014
L1014
|- style="vertical-align: top;"| Distance | 652.32 Ly Lynds 1014 is a dark nebula in Cygnus constellation. It may be among the most centrally condensed small dark cloud known, perhaps indicative of the earliest stages of star formation processes...
which had previously appeared completely dark to ground-based observatories and to ISO (Infrared Space Observatory
Infrared Space Observatory
The Infrared Space Observatory was a space telescope for infrared light designed and operated by the European Space Agency , in cooperation with ISAS and NASA...
), a predecessor to Spitzer. The advanced technology of Spitzer revealed a bright red hot spot in the middle of L1014.
Scientists from the University of Texas at Austin
University of Texas at Austin
The University of Texas at Austin is a state research university located in Austin, Texas, USA, and is the flagship institution of the The University of Texas System. Founded in 1883, its campus is located approximately from the Texas State Capitol in Austin...
, who discovered the object, believe the hot spot to be an example of early star development, with the young star collecting gas and dust from the cloud around it. Early speculation about the hot spot was that it might have been the faint light of another core that lies 10 times further from Earth but along the same line of sight as L1014. Follow-up observation from ground-based near-infrared observatories detected a faint fan-shaped glow in the same location as the object found by Spitzer. That glow is too feeble to have come from the more distant core, leading to the conclusion that the object is located within L1014. (Young et al., 2004)
In 2005, astronomers from the University of Wisconsin
University of Wisconsin System
The University of Wisconsin System is a university system of public universities in the state of Wisconsin. It is one of the largest public higher education systems in the country, enrolling more than 182,000 students each year and employing more than 32,000 faculty and staff statewide...
at Madison
University of Wisconsin–Madison
The University of Wisconsin–Madison is a public research university located in Madison, Wisconsin, United States. Founded in 1848, UW–Madison is the flagship campus of the University of Wisconsin System. It became a land-grant institution in 1866...
and Whitewater determined, on the basis of 400 hours of observation on the Spitzer Space Telescope, that the Milky Way Galaxy has a more substantial bar structure across its core than previously recognized.
Also in 2005, astronomers Alexander Kashlinsky
Alexander Kashlinsky
Alexander Kashlinsky is an astronomer and cosmologist, better known for discovery of a phenomenon called dark flow.-Biography:*1976-1979: Tel Aviv University, Israel, Departament of Physics & Astronomy...
and John Mather
John C. Mather
John Cromwell Mather is an American astrophysicist, cosmologist and Nobel Prize in Physics laureate for his work on the Cosmic Background Explorer Satellite with George Smoot. COBE was the first experiment to measure ".....
of NASA's Goddard Space Flight Center
Goddard Space Flight Center
The Goddard Space Flight Center is a major NASA space research laboratory established on May 1, 1959 as NASA's first space flight center. GSFC employs approximately 10,000 civil servants and contractors, and is located approximately northeast of Washington, D.C. in Greenbelt, Maryland, USA. GSFC,...
reported that one of Spitzer's earliest images may have captured the light of the first stars in the universe. An image of a quasar
Quasar
A quasi-stellar radio source is a very energetic and distant active galactic nucleus. Quasars are extremely luminous and were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than...
in the Draco
Draco (constellation)
Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere...
constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
, intended only to help calibrate the telescope, was found to contain an infrared glow after the light of known objects was removed. Kashlinsky and Mather are convinced that the numerous blobs in this glow are the light of stars that formed as early as 100 million years after the big bang
Big Bang
The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...
, red shift
Red shift
-Science:* Redshift, the increase of wavelength of detected electromagnetic radiation with respect to the original wavelength of the emission* Red shift, an informal term for a bathochromic shift...
ed by cosmic expansion.
In March 2006, astronomers reported an 80-light-year-long nebula near the center of the Milky Way Galaxy, the Double Helix Nebula
Double Helix Nebula
The Double Helix Nebula is a gaseous nebula near the center of our galaxy. It is thought to have been distorted by magnetic torsion into the shape of two connected spirals, known popularly as a double helix, akin to the shape of DNA....
, which is, as the name implies, twisted into a double spiral shape. This is thought to be evidence of massive magnetic fields generated by the gas disc orbiting the supermassive black hole
Supermassive black hole
A supermassive black hole is the largest type of black hole in a galaxy, in the order of hundreds of thousands to billions of solar masses. Most, and possibly all galaxies, including the Milky Way, are believed to contain supermassive black holes at their centers.Supermassive black holes have...
at the galaxy's center, 300 light years from the nebula and 25,000 light years from Earth. This nebula was discovered by the Spitzer Space Telescope, and published in the magazine Nature on March 16, 2006.
In May 2007, astronomers successfully mapped the atmospheric temperature of HD 189733 b
HD 189733 b
HD 189733 b is an extrasolar planet approximately 63 light-years away in the constellation of Vulpecula . The planet was discovered orbiting the star HD 189733 on October 5, 2005, when astronomers in France observed the planet transiting across the face of the star. The planet is classified as a...
, thus obtaining the first map of some kind of an extrasolar planet.
Gould Belt Survey
The Gould Belt Survey is an astronomical research project led by the Harvard-Smithsonian Center for Astrophysics, with the participation of several other institutions....
, observing the Gould's Belt
Gould Belt
The Gould Belt is a partial ring of stars in the Milky Way galaxy, about 3000 light years across, tilted toward the galactic plane by about 16 to 20 degrees. It contains many spectral class O- and B-type stars, and may represent the local spiral arm to which the Sun belongs—currently the Sun is...
region in multiple wavelengths. The first set of observations by the Spitzer Space Telescope were completed from September 21, 2006 through September 27. Resulting from these observations, the team of astronomers led by Dr. Robert Gutermuth, of the Harvard-Smithsonian Center for Astrophysics
Harvard-Smithsonian Center for Astrophysics
The Harvard–Smithsonian Center for Astrophysics is one of the largest and most diverse astrophysical institutions in the world, where scientists carry out a broad program of research in astronomy, astrophysics, earth and space sciences, and science education...
reported the discovery of Serpens South
Serpens south
The Serpens South star cluster is a relatively dense group of 50 young stars, 35 of which are protostars just beginning to form. The cluster is situated in the southern portion of the Serpens cloud, located approximately 848 light-years away from Earth....
, a cluster of 50 young stars in the Serpens
Serpens
Serpens is a constellation of the northern hemisphere. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy and it remains one of the 88 modern constellations defined by the International Astronomical Union....
constellation.
In August 2009, the telescope found evidence of a high-speed collision between two burgeoning planets orbiting a young star.
In October 2009, astronomers Anne J. Verbiscer, Michael F. Skrutskie, and Douglas P. Hamilton published findings of the "Phoebe ring" of Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
, which was found with the telescope; the ring is a huge, tenuous disc of material extending from 128 to 207 times the radius of Saturn.
GLIMPSE and MIPSGAL surveys
GLIMPSE, the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire, is a survey spanning 300° of the inner Milky Way galaxy. It consists of approximately 444,000 images taken at 4 separate wavelengths using the Infrared Array Camera.MIPSGAL is a similar survey covering 278° of the galactic disk at longer wavelengths.
On June 3, 2008, scientists unveiled the largest, most detailed infra-red portrait of the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
, created by stitching together more than 800,000 snapshots, at the 212th meeting of the American Astronomical Society
American Astronomical Society
The American Astronomical Society is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC...
in St.Louis, Missouri
Missouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
.
This composite survey is now viewable with the GLIMPSE/MIPSGAL Viewer.
See also
- Infrared astronomyInfrared astronomyInfrared astronomy is the branch of astronomy and astrophysics that studies astronomical objects visible in infrared radiation. The wavelength of infrared light ranges from 0.75 to 300 micrometers...
- Zooniverse - The Milky Way Project