... Star Trails in Northern Skies . ... This motion produces the beautiful concentric trails traced by the stars in this time exposure of the night sky. In the middle of the picture is the North Celestial Pole (NCP) , easily identified as the point in the sky at the center of all the star trail arcs. ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ... Публикации с ключевыми словами: north star - star trail - Полюс мира - суточное вращение - вращение Земли . ...