Starting from the 25th, a planetary alignment featuring seven planets of the solar system will appear in a line in the night sky. Since January, six planets have been aligned, and this time, Mercury has joined as well. This planetary alignment phenomenon will last until the 28th, and in March, Saturn will descend below the horizon and will be unobservable.
The planets will rise in the order of Mars, Jupiter, Uranus, Venus, Neptune, Mercury, and Saturn. To observe the planetary alignment, it is important to choose a dark location where the western sky is well visible. Particularly, it is essential to pay attention from early evening when Taeyang disappears below the horizon.
The brightest planet is Venus. Mars and Jupiter are also relatively bright and easy to observe. Mercury and Saturn are at a low altitude and quickly disappear from the sky, so observations should be made promptly from early evening. Neptune and Uranus may only be faintly visible unless the sky is completely dark, so a telescope is needed.
Planetary alignment occurs because the orbits of the planets around the Taeyang are similar in plane. In simpler terms, it's like placing several balls on a table and looking at them from the side, where they appear to be arranged in a line.
Of course, the planets do not actually align perfectly in a straight line. Jeon Young-beom, a senior researcher at the Korea Astronomy and Space Science Institute, noted, "Since the planets of the solar system do not occupy the same height, rather than being neatly connected in a line, they are closer to a bumpy form."
Ahn In-seon, a researcher at the National Gwacheon Science Museum, said, "Every year, planetary alignments involving four to five planets occur multiple times, but only two to three can be seen with the naked eye," adding that "the next favorable planetary alignment for observation is expected to occur on Sept. 8, 2040."