Astronomy Picture of the Day

Explanation: Three major sources contribute to the far-infrared sky: our Solar System, our Galaxy, and our Universe. The above recently released image, in representative colors, is the highest resolution projection yet created of the entire far-infrared sky (240 microns) created from years of observations by the now-defunct robot spacecraft COBE. Our Solar System is evidenced most prominently by the S-shaped blue sash called zodiacal light, created by small pieces of rock and dust orbiting between the Sun and Jupiter. The disk of our Galaxy is evidenced most prominently by the thin band of light-emitting dust that crosses the middle of the image. Clouds and filaments of dust in our Milky Way also make intricate patterns pervading most of the sky. Close inspection of similar images reveal that the background is not completely dark, indicating that our Universe itself provides a diffuse glow, created by dust left over from the star formation throughout the Universe.