At the observatory.
As time slowly passed, the astronomers observed Mercury using various instruments while engaging in discussions with each other.
Old Yi stood quietly by their side, listening. The content of their conversation was nothing but professional knowledge like the orbital angle changes of Mercury.
Due to Mercury being too close to the Sun, it is mostly obscured by the Sun's light when observed from Earth, often completely drowning it out.
It is only visible for a short period each year.
Even during that period, Mercury can only be observed at dawn or dusk, in the brief moments when it rises before or sets after the Sun.
Unlike most other astronomical observations, it cannot be observed against the backdrop of the dark night sky for an extended period.
