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 image, in representative colors, is a projection of the entire infrared sky created from years of observations by the 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. Our Galaxy is evidenced by the bright band of light that crossed the middle of the image, created mostly by dust that laces the disk of our Milky Way. Close inspection of the image reveals that the background is not completely dark, indicating that our Universe itself provides a diffuse glow, created by the dust left over from the star formation throughout the Universe.

構成紅外光天空的光，有3種主要來源：我們的太陽系、我們的銀河系、和我們的宇宙。 上面這張代表色圖像，是COBE衛星多年在紅外光波段觀測天空的數據之投影。 我們的太陽系是其中最鮮明的紅外光源，太陽和木星之間軌道上的小石塊和塵埃所產生的S形泛藍光帶（稱為黃道光），即可為證。 我們的銀河系為橫跨圖像中心的亮帶，主要來自銀河系盤面上的塵埃所發出的輻射。 如仔細檢視圖像，可發現背景並非完全黝黑，這顯示我們的宇宙有瀰漫的輝光，其源頭為遍布整個宇宙、在恆星形成過程中所遺留下來的塵埃之輻射。