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Herschel mission graphic

Herschel Space Observatory

Phase: Past

Launch Date: May 14, 2009

Mission Project Home Page -

Program(s):Cosmic Origins

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Herschel's infrared image of the Andromeda Galaxy shows rings of dust that trace gaseous reservoirs where new stars are forming and XMM-Newton's X-ray image shows stars approaching the ends of their lives. Both infrared and X-ray images convey information impossible to collect from the ground because these wavelengths are absorbed by Earth's atmosphere. Credits: ESA/Herschel/PACS/SPIRE/J.Fritz, U.Gent/XMM-Newton/EPIC/W. Pietsch, MPE

The Herschel Space Observatory is a space-based telescope that is studying the light of the Universe in the far-infrared and submillimeter portions of the spectrum. It is revealing new information about the earliest, most distant stars and galaxies, as well as those closer to home in space and time. It is also taking a unique look at our own Solar System.

Herschel is the fourth Cornerstone mission in the European Space Agency’s Horizon 2000 program. Ten countries, including the United States, participated in its design and implementation. Launched on May 14, 2009, the mission will operate until the cryostat runs out of helium during the first half of 2013. The mission will operate until the cryostat runs out of helium, perhaps four years after launch. Originally called “FIRST,” for “Far InfraRed and Submillimeter Telescope,” the spacecraft was renamed for Britain’s Sir William Herschel, who discovered in 1800 that the spectrum extends beyond visible light into the region we today call “infrared.”

Herschel’s namesake will give scientists their most complete look so far at the large portion of the Universe that radiates in far-infrared and submillimeter wavelengths. With a primary mirror 3.5 meters (approximately 11.5 feet) in diameter, Herschel is the largest infrared telescope sent into space as of its launch date. Using detectors cooled to temperatures very close to absolute zero (0 degree Kelvin), the three instruments called HIFI, SPIRE, and PACS, which enables Herschel to be the first spacecraft to observe in the full 60-670 micron range.

The far-infrared and submillimeter wavelengths at which Herschel observes are considerably longer than the familiar rainbow of colors that the human eye can perceive. Yet, this is a critically important portion of the spectrum to scientists because it is the frequency range at which a large part of the universe radiates.

Much of the Universe consists of gas and dust that is far too cold to radiate in visible light or at shorter wavelengths such as x-rays. However, even at temperatures well below the most frigid spot on Earth, they do radiate at far-infrared and submillimeter wavelengths.

Stars and other cosmic objects that are hot enough to shine at optical wavelengths are often hidden behind vast dust clouds that absorb the visible light and re-radiate it in the far-infrared and submillimeter range.

Last updated: October 26, 2012

Related Links
  • ESA Herschel Website -
  • More about Herschel -
  • Science@ESA - ISO/Herschel video -