Herschel

The "Herschel Space Observatory" (named after Wilhelm Herschel, the discoverer of infrared radiation) is a 3.4-metric-ton space telescope developed by the ESA that was launched in May 2009. Herschel is the first space telescope to cover the entire wavelength range from the far infrared to the submillimeter range, allowing for the observation of otherwise invisible cold and dusty regions of the cosmos. With its primary mirror measuring 3.5 meters in diameter (1.5 times larger than that of the Hubble Telescope), Herschel can collect nearly 20 times more light than any previous infrared telescope.

Among Herschel’s main objectives were studies of:

• the formation and evolution of galaxies, particularly distant young galaxies that, due to their dust content, emit primarily in the far infrared;
• The formation and evolution of stars, for example through a large-scale search for the earliest stages of stellar development;
• The physics and chemistry of interstellar matter;
• objects in our solar system (comets and planetary atmospheres).

The Herschel satellite carries three instruments on board:

• HIFI (Heterodyne Instrument for Far Infrared): high-resolution spectrometer (157–625 µm)
• PACS (Photodetector Array Camera and Spectrometer): imaging photometer/spectrometer (57–210 µm)
• SPIRE (Spectral and Photometric Image Receiver): imaging photometer/spectrometer (200–670 µm)