Z代表火星
(原标题: When Z is for Mars)
2023-04-15
浏览次数: 15
从2022年8月中旬到2023年3月下旬，大约间隔一周拍摄的图像合成，这一系列追踪了红色火星的逆行运动。从右下到左上，火星沿着z形的路径穿过昴宿星团和毕宿星团，穿过地球夜空中的金牛座。火星每两年出现一次，实际上它并没有改变轨道的方向来画出z形。相反，相对于背景恒星的明显的向后或逆行运动是地球自身轨道运动的反映。每当地球超过并超过离太阳更远的行星时，就会出现逆行运动，地球在自己相对较近的轨道上运行得更快。12月8日，在北半球的天空中，这颗红色的行星正对着太阳，距离太阳最近，也最亮，接近画面的中心。2月10日和2月16日，在火星附近，一个受欢迎的内太阳系访客，彗星ZTF （C/2022 E3）也被捕获。
查看原文解释
A composite of images captured about a week apart from mid August 2022 through late March 2023, this series traces the retrograde motion of ruddy-colored Mars. Progressing from lower right to upper left Mars makes a Z-shaped path as it wanders past the Pleiades and Hyades star clusters, through the constellation Taurus in planet Earth's night sky. Seen about every two years, Mars doesn't actually reverse the direction of its orbit to trace out the Z-shape though. Instead, the apparent backwards or retrograde motion with respect to the background stars is a reflection of the orbital motion of Earth itself. Retrograde motion can be seen each time Earth overtakes and laps planets orbiting farther from the Sun, the Earth moving more rapidly through its own relatively close-in orbit. High in northern hemisphere skies the Red Planet was opposite the Sun and at its closest and brightest on December 8, near the center of the frame. Seen close to Mars, a popular visitor to the inner Solar System, comet ZTF (C/2022 E3), was also captured on two dates, February 10 and February 16.
© Tunc Tezel