Close to the horizon where to watch refers to the point on the horizon where celestial objects, such as the sun, moon, or stars, appear to be closest to the observer. This point is typically located at the vanishing point of the celestial sphere, where the horizon meets the celestial equator and the ecliptic (the apparent path of the sun across the sky).
Watching celestial objects close to the horizon can provide several benefits. Firstly, the objects appear larger and brighter due to atmospheric refraction, making them easier to observe. Secondly, the lower altitude of the objects allows for a clearer view, as there is less atmospheric interference. This is particularly important for observing details on the surfaces of planets and moons.