- This article is about the future ESA space telescope. For the telescope on the Canary Islands, see William Herschel Telescope
| Herschel Space Observatory | |
|---|---|
 Artist's impression of the Herschel Space Observatory |
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| General information | |
| Alternative names: | Far Infrared and Submillimetre Telescope (FIRST) |
| Organization: | ESA |
| Launched: | July 2008 (delayed from July 2007 |
| Deorbited: | 2010 - 2011 |
| Mass: | 3,300 kg |
| Orbit height: | 1.5×106km from Earth (L2 Lagrangian point) |
| Orbit period: | 1 year |
| Orbit velocity: | 7,500 m/s, 16,800 mph (27,000 km/h) |
| Type of orbit: | Lissajous orbit |
| Telescope style: | Cassegrain reflector |
| Wavelength: | infrared: 60 to 670 µm |
| Diameter: | 3500 mm, f/0.5 |
| Collecting area: | 9.6 m² |
| Focal length: | 27000 mm |
| Instruments | |
| HIFI: | Heterodyne Instrument for the Far Infrared |
| PACS: | Photodetector Array Camera and Spectrometer |
| SPIRE: | Spectral and Photometric Imaging Receiver |
| Website: | http://www.esa.int/esaSC/120390_index_0_m.html |
The Herschel Space Observatory is a mission of the European Space Agency. The satellite, built in the Cannes Mandelieu Space Center, is to be launched in 2008 aboard an Ariane 5 rocket together with Planck and will enter a 700,000 km diameter Lissajous orbit around the second Lagrangian point of the Earth-Sun system, 1.5 million kilometres away from Earth.[1] The mission is named after Sir William Herschel, who discovered the infrared spectrum.[1]
Contents |
Instrument
The mission, formerly titled the Far Infrared and Sub-millimetre Telescope (or FIRST),[2] will be the first space observatory to cover the full far infrared and submillimetre waveband, and its telescope will have the largest mirror ever deployed in space (three and a half metres wide).[3] The light will be focused onto three instruments with detectors kept at temperatures below 2 K. The instruments will be cooled with liquid Helium, boiling away in near vacuum at a temperature of ~1.4 K. The (operational) lifetime is limited by the amount of Helium on board the satellite. The three detectors on board Herschel will be:[4]
- PACS (Photodetecting Array Camera and Spectrometer) will be an imaging camera and low resolution spectrometer with coverage from 55 to 210 micrometres. The spectrometer will have a resolution between 1000 and 5000 and be able to detect signals as weak as a few times 10-18 W/m². The imaging camera will be able to image simultaneously in two bands (either 60-85 micrometres or 85-130 micrometres, as well as 130-210 micrometres) with a detection limit of a few millijanskies.[5]
- SPIRE (Spectral and Photometric Imaging Receiver) will be an imaging camera and low resolution spectrometer with coverage from 194 to 672 micrometres. The spectrometer will have a resolution between 40 and 1000 at wavelengths of 250 micrometres and be able to image point sources with brightnesses around 100 millijanskies and extended sources with brightnesses of around 500 millijanskies.[6] The imaging camera has three bands, centered at 250, 350 and 500 micrometres, which have 139, 88 and 43 pixels respectively. The imaging camera can detect point sources with brightness above 2 millijanskies and for extended sources the threshold is between 4 and 9 millijanskies.
- HIFI (Heterodyne Instrument for the Far Infrared) will be a high resolution spectrograph. The spectrometer has a resolution as high as 107.[7] The spectrograph covers two wavelength bands, from 157 to 212 micrometres and from 240 - 625 micrometres.
Science
Herschel will specialise in collecting light from objects in our solar system as well as further into the Milky Way and even extragalactic objects, such as newborn galaxies billions of light-years away. The science goals of Herschel are[2]:
- To investigate galaxy formation in the early universe and the evolution of galaxies,
- To investigate star formation and its interaction with the interstellar medium,
- To investigate the chemical composition of atmospheres and surfaces of solar system bodies, including planets, comets and moons,
- To investigate molecular chemistry across the universe.
References
- Harwit M.. "The Herschel mission". Advances in Space Research 34 (3): 568-572. doi:10.1016/j.asr.2003.03.026.
- ^ a b Herschel Factsheet (1 February 2007). Retrieved on 2007-09-29.
- ^ a b Herschel. European Space Agency Science & Technology. Retrieved on 2007-09-29.
- ^ Herschel Space Observatory. Imperial College. Retrieved on 2007-09-29.
- ^ Herschel. European Space Agency. Retrieved on 2007-09-29.
- ^ PACS - Photodetector Array Camera and Spectrometer. Retrieved on 2007-09-29.
- ^ SPIRE - Spectral and Photometric Imaging Receiver. European Space Agency. Retrieved on 2007-09-29.
- ^ HIFI - Heterodyne Instrument for the Far Infrared. European Space Agency. Retrieved on 2007-09-29.
External links
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| Great Observatories program | Hubble Space Telescope · Compton Gamma-Ray Observatory · Chandra X-ray Observatory · Spitzer Space Telescope |
| NASA | Swift Gamma-Ray Burst Mission · Wilkinson Microwave Anisotropy Probe |
| European Space Agency | COROT · INTEGRAL · XMM-Newton |
| Other countries | ASTRO-E (Japan) |
| Future telescopes | Gamma-ray Large Area Space Telescope (2008) · Herschel Space Observatory (2008) · Kepler Mission (2009) · Wide-field Infrared Survey Explorer (2009) · NuSTAR (2011) · Gaia mission (2011) · James Webb Space Telescope (2013) · New Worlds Mission (2013) · Space Interferometry Mission (2015) · Darwin Mission (2015) · Laser Interferometer Space Antenna (2015) · Terrestrial Planet Finder (TPF) |
| Completed missions | Cosmic Background Explorer · Einstein Observatory · Far Ultraviolet Spectroscopic Explorer · IRAS · Infrared Space Observatory · AKARI |
| Canceled telescopes | Eddington mission |
