Astronomy Picture of the Day . Mercury on the Horizon . ... Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth's sky . If trailing the Sun, Mercury will be visible low on the horizon for only a short while after sunset . ... Mercury is currently visible in the western sky after sunset, but will disappear in the Sun's glare after a few days. ... Publications with keywords: Mercury - horizon - sunset . Publications with words: Mercury - horizon - sunset . ...