3月28日晨，东南方天空上演神奇一幕：金星、火星和土星这三颗行星与一弯残月“同框”了，我国不少天文摄影爱好者拍下了这四个明亮天体“同框”的罕见画面。据了解，3月29日晨，这三颗行星与残月会再次“同框”，只是星月的相互位置有些许变化。
On the morning of March 28, a magical scene was staged in the southeastern sky: the three planets Venus, Mars and Saturn were "in the same frame" with a crescent moon. Many astrophotography enthusiasts in our country photographed these four bright celestial bodies "in the same frame". "A rare picture. It is understood that on the morning of March 29, the three planets and the waning moon will be "in the same frame" again, but the mutual positions of the stars and moons will change slightly.
The five bright planets in the solar system, Mercury, Venus, Mars, Jupiter, and Saturn, orbit the sun together. Because the five planets move at different speeds, the faster planet sometimes passes by the other planet, making the two planets appear very close, forming a planetary conjunction; sometimes, several planets even come together at the same time and gather in A smaller area in the sky called a planetary meeting.
From the end of March to the beginning of April, Venus, Mars and Saturn will have a relatively close reunion. Among them, they were the closest on March 28 and 29, and the three gathered within a range of just over 5 degrees. Coincidentally, on the 28th, a waning moon will join the ranks of these three planets and conjoin them in turn.
However, in our country, the three stars are below the horizon when they conjoin the moon, and people cannot observe the closest moment between the moon and the planets. "Our observation opportunities can only be on the morning of March 28, before the moon and the three planets approach; or on the morning of March 29, after the moon and the three planets approach, the three stars of gold, fire, and earth accompany the moon." said Kou Wen, a senior engineer at the Beijing Planetarium.
Among the three planets, the most eye-catching is the extremely bright Venus, with a brightness of -4.3 and the highest altitude; before dawn on the 28th, Saturn is about 2 and a half degrees below Venus, with a brightness of 0.8; the dimest Mars is more than 5 degrees to the right of Venus, and its brightness is only 1.1 magnitude; the crescent moon is on the right side of the three planets, the closest to Mars. On the 29th, the positions of the three planets did not change much. Compared with the previous day, the distance between Venus and Saturn was closer. At this time, the crescent moon was thinner than the previous day, and the altitude was lower. It has reached three planets. Below the stars, it is difficult to observe.
"It is rare for these three planets to meet at such a close distance. The last time they closely met was in the evening of early August 2010, and the scope of the gathering was smaller than this time. In June 2032, they will meet again, only at a distance. The sun is too close to be seen from the ground."
In early September 2040, the three planets Venus, Mars, and Saturn will come together again at close range, Cowan said. It is very rare that the other two of the five planets, Mercury and Jupiter, will also join their ranks and gather within a range of less than 10 degrees, forming a five-star convergence phenomenon that has not been encountered in a century.
"What's even more rare is that on the evening of September 8, 2040, the moon will walk among them. The six celestial bodies in the solar system are distributed in such a small area and appear together in the low western sky in the evening. It is a rare astronomical spectacle in life. ."
rare! The golden fire, earth and moon are in the same frame, and the picture is spectacular: the next time will be reproduced in 2032
太阳系中五颗明亮的行星水星、金星、火星、木星、土星共同围绕太阳运行。由于五颗行星运行速度不同，速度快的行星有时会从另一颗行星旁边经过，使得两颗行星看起来非常接近，形成行星相合；有时，甚至会有几颗行星同时走到一起，聚集在天空中一个较小的范围内，称为行星相聚。
3月底到4月初，金星、火星、土星就会发生一次比较近距离的相聚。其中，3月28日、29日时它们最为接近，三者聚集在仅仅只有5度多的范围内。非常巧合的是，28日，一轮残月会加入到这三颗行星的行列，依次和它们相合。
不过，在我国，三星合月时都处于地平线以下，人们无法观测到月亮和行星们最接近的时刻。“我们的观测机会只能在3月28日早晨，月亮和三颗行星接近之前；或者在3月29日早晨，观看月亮和三颗行星接近之后的金、火、土三星伴月景象。”北京天文馆高级工程师寇文说。
三个行星中，最引人瞩目的是异常明亮的金星，亮度达-4.3等，地平高度也最高；28日早晨天亮前，土星在金星下方约2度半，亮度0.8等；亮度最暗的火星在金星右侧5度多，亮度只有1.1等；弯弯的月牙儿在三颗行星的右侧，距离火星最近。29日，三颗行星位置变化不大，与前一天相比，金星、土星之间的距离更近一些，此时的月牙儿比前一天更细，地平高度也更低，已经跑到了三颗星的下方，观测起来有一定的难度。
“这三颗行星这样近距离的相聚比较难得，它们上一次紧密相合是在2010年8月初的傍晚，聚集的范围比这次还要小一些。2032年6月，它们将再次相聚，只是距离太阳过近，地面无法观测。”
寇文说，2040年9月初，金星、火星、土星这三颗行星又将近距离地会聚在一起。十分难得的是，五大行星中另外两颗水星和木星也将加入到它们的行列，聚集在不到10度的范围内，形成百年不遇的五星汇聚现象。
“更加难得的是，2040年9月8日傍晚，月亮会走到它们中间，太阳系中六大天体分布在如此小的范围内，共同出现在傍晚的西方低空，真是人生难得一见的天象奇观。”
罕见！金火土月同框了 画面很壮观：下次重现2032年
