Space Observatory

An ESA Mission
with Participation from NASA


Herschel's Multi-Hued View of the Sky

Feature • October 2, 2009

A new image from the Herschel Space Observatory shows off the observatory's talents for seeing multiple wavelengths of light. The infrared observatory, a European Space Agency mission with important participation from NASA, can use two science instruments simultaneously to see five different "colors" of infrared, which is light that we can't see with our eyes.

The new composite picture features a dark and cool region of our Milky Way galaxy, where material is just beginning to be stirred together into new batches of stars. Much of this region would appear dark in visible-light views, but Herschel can see the very dim infrared glow of cold dust that is only slightly warmer than the coldest temperature theoretically attainable. Herschel's view reveals that this star-forming region is even richer in cold and turbulent material than previously believed.

"Herschel's infrared vision lets us sense the feeble heat from some of the coldest objects in the cosmos," said Paul Goldsmith, the NASA project scientist for the mission at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Herschel is still in what is called the performance verification phase, in which its instruments are being fine-tuned and checked out. Some routine science observations have begun.

The new image is a combination of data taken with Herschel's photodetector array camera and spectrometer, and its spectral and photometric imaging receiver. By using these two instruments at the same time, Herschel won't need to use as much of its stored liquid coolant, a limited resource expected to last about three-and-a-half years.

In the color-coded image, blue shows warmer dust and red, the coolest, with green representing temperatures in between. The coldest dust can be seen as thin filaments. It is here that stars are in the very earliest stages of their infancy, and can be seen lined up together like glittering beads of water on a blade of grass.

More images like this are expected in the future and will ultimately help astronomers map the "terra incognita," or unknown land, of our Milky Way, as well as other galaxies that are farther away.

Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at NASA's Jet Propulsion Laboratory. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA.