M66 (also known as NGC 3627) is a barred spiral galaxy located about 36 million light years away in the constellation Leo. The bar is made of stars, gas, and dust. The infrared SPIRE image shows warm dust, revealing that most of the dust is located in the centre of the galaxy and near the ends of the bar. Dust is also found in the spiral arms. This arrangement is caused by the forces that the bar exerts on other objects within the galaxy. Many more distant galaxies appear as blobs in the field of view.
Herschel’s primary mirror is 3.5 m in diameter, nearly four times larger than any previous infrared space telescope. These images prove that Herschel enables a giant leap forward in our ability to study celestial objects at far infrared wavelengths. NASA’s Spitzer Space Telescope primarily observes infrared wavelengths shorter than Herschel does, so the two telescopes complement each other.