Astronomy Picture of the Day

Explanation: The Sloan Digital Sky Survey (SDSS) will soon begin. Pictured above is the 2.5-meter telescope poised to create the most ambitious sky map in the history of astronomy. SDSS will catalog one quarter of the sky down past 23rd magnitude ( R), obtaining redshifts for galaxies and quasars brighter than magnitude 19. SDSS is expected to store about 200 Gigabytes of data each night. Astronomers will work to cull from this information an unprecedented three-dimensional view of our local universe. However, the SDSS may one day be remembered not only for the hundreds of million of objects which it could see, but for how it indicated the nature and composition of the rest of the universe which it could not see.

史隆數位巡天計劃（SDSS）即將啟動。 上圖的2.5米口徑望遠鏡，已經就位並預備協助製作天文學史上最具雄心的星空圖。 SDSS將對四分之一天空中，亮度低於23星等的天體進行編錄，並取得比19等更亮的星系和類星體之紅移。 SDSS預計每晚將存儲大約200吉（十億）位元的資料。 天文學家們將努力篩選這些資訊，以建構本區宇宙的空前三維星圖。 然而或許有一天，SDSS除了會因它能看到數以億計的天體而為人所知之外，也會因為它看不卻隱指的其餘宇宙之性質和組成而著稱。