M51 seen by Spitzer (left) and Herschel (right)

Comparison of M51 imaged with the Spitzer Space Telescope (left panel) and an image of the same galaxy taken with the Herschel Space Observatory (right panel), launched just a month ago.

The obvious advantage of the larger size of the telescope is clearly reflected in the much higher resolution of the image: Herschel reveals structures that cannot be discerned in the Spitzer image. Both images were taken at the wavelength of 160 microns.