SkyEye

The upper chart shows the path of Mercury across the background stars over the course of the year. Stars to magnitude +4.5 are shown with some fainter objects included to complete constellation patterns. The white circles represent the planet on the first day of the month and are scaled according to apparent magnitude. The faint paths before the first circle and after the last circle represent the planet's positions in December of last year and January of next. In general, the planet moves from right to left except when it's in retrograde and proceding in the opposite direction. As an inferior planet, Mercury never strays far from the Sun so it always begins and ends the year near the constellation of Sagittarius, located about one quarter of the way in from the left side of the chart.

The lower charts show how the appearance of Mercury changes over the year. Below each image is listed the date, the apparent magnitude, the apparent diameter of the disk (in arc-seconds), the geocentric distance (in au), the elongation from the Sun (in degrees) and the percentage of the disk which is illuminated. Like the Moon, Mercury exhibits a complete range of phases, from new to crescent to gibbous to full and back again. Because its synodic period is around four months, Mercury completes this phase cycle three times each year. Note how Mercury's magnitude varies widely, ranging (approximately) from −2.0 to +6.0 between conjunctions.

Mercury begins and ends 2025 in the morning sky. The best dawn apparitions for northern hemisphere observers occur in August–September and from November onwards. The best morning views from the southern hemisphere take place between late March and June. Southern hemisphere astronomers have two excellent evening apparitions of the tiny planet, in June–July and again from mid-September to mid-November. Those in northern temperate latitudes should look to the west between early February and late March for their best chance to spot elusive Mercury in evening twilight. The closest planet to the Sun has conjunctions with all of the other planets, usually when they themselves are near solar conjunction, and is occulted by the Moon once, in early March.

All times and dates are in UT with the time given to the nearest hour unless otherwise indicated. Positions are geocentric apparent places and referred to the true equator and equinox of date.

• Apparitions of the Inferior Planets from Latitude 50° North
• Apparitions of the Inferior Planets from Latitude 10° North
• Apparitions of the Inferior Planets from Latitude 30° South