This was explained by Engineer Majed Abu Zahra
The planet Mercury will reach its eastern maximum on Monday, January 25, 2021, in the evening sky, and the opportunity is ready to be seen with the naked eye towards the western horizon.
Mercury is often called the “elusive planet.” Most of us have seen Venus, Mars or Jupiter shining in the sky, but not Mercury, despite the small size of Mercury, but it is too bright to be observed with the naked eye, but we often do not see it.
Mercury is the closest planet to the sun and most of the time it is obscured by the glare of sunlight, which is why not many people have seen Mercury before, however, at certain times, the planet becomes visible to us.
The best time to observe Mercury is when the planet reaches its maximum angle from the sun, as seen from the Earth, and this event is called the “greatest elongation” and it occurs every 70-40 days and is a fun time for any fan of astronomy.
There are two types of extensions – eastern and western. When Mercury is east of the Sun, it is an afternoon westerly elongation, and when it is on the west side of the Sun, it is a westerly morning elongation.
The maximum elongation angle of Mercury ranges from 18 degrees to 28 degrees east or west of the sun. The reason for this difference is because Mercury’s orbit is not completely circular.
You can start searching for the planet in the western sky at sunset and you should not wait for long, because Mercury will be very low at an altitude of 18 degrees above the horizon and will set an hour or two after sunset, depending on the geographical location.
Mercury will appear like a bright “evening star” (-0.7) in the constellation of Capricorn. It can be observed with the naked eye, preferably through binoculars, and with a telescope one can see the phases of Mercury that resemble the phases of the moon.
Try not to miss the opportunity to see Mercury this month. If you miss it, the opportunity will arise again during the westerly mornings in March.