What is the phase of Mercury today?
Today, October 11, 2026, Mercury is in the waning gibbous phase and is 62% illuminated in its phase cycle. Through a telescope, it appears less than full but more than half-illuminated.
Mercury phases for 2026
Here are the dates for all the phases of Mercury in 2026:
- Full phase of Mercury: January 21, 2026
- Third quarter phase of Mercury: February 19, 2026
- New phase of Mercury: March 7, 2026
- First quarter phase of Mercury: April 3, 2026
- Full phase of Mercury: May 14, 2026
- Third quarter phase of Mercury: June 9, 2026
- New phase of Mercury: July 13, 2026
- First quarter phase of Mercury: August 5, 2026
- Full phase of Mercury: August 27, 2026
- Third quarter phase of Mercury: October 17, 2026
- New phase of Mercury: November 4, 2026
- First quarter phase of Mercury: November 18, 2026
- Full phase of Mercury: January 1, 2027
The phases of Mercury
You cannot observe the phases of Mercury with the naked eye. To see them, you will need a telescope.
Mercury takes about 116 days to travel from one new phase to the next new phase. This period is called the phase cycle of Mercury.
In a phase cycle, Mercury goes through the following phases in order: new, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, third quarter, and waning crescent.
New phase of Mercury: Mercury exhibits its new phase when it passes between the sun and Earth in its orbit, an astronomical event known as the inferior conjunction of Mercury.
The new phase of Mercury is not visible in the sky for two reasons:
- The illuminated side of Mercury—the day side—turns completely away from us.
- It rises and sets with the sun, making it impossible to observe.
Waxing crescent phase of Mercury: About a few days after its inferior conjunction, a thin, sickle-shaped Mercury—a waxing crescent phase of Mercury—appears in the eastern sky before sunrise. Each day, its illuminated area increases but disk size decreases.
First quarter phase of Mercury: Mercury exhibits its first quarter phase around its greatest western elongation from the sun when its phase angle—the angle between the sun, Mercury and Earth—is 90°. During the phase, a half-illuminated Mercury (like a half-moon) appears in the eastern sky before sunrise.
Waxing gibbous phase of Mercury: About a few days after its greatest western elongation, a more than half-illuminated but less than full Mercury—a waxing gibbous phase of Mercury—appears in the eastern sky before sunrise. Each day, its illuminated area increases but disk size decreases until it becomes a full Mercury.
Full phase of Mercury: Mercury exhibits its full phase when it passes almost directly behind the sun from Earth’s perspective, an astronomical event known as the superior conjunction of Mercury. The full phase of Mercury is not visible in the sky as it rises and sets with the sun.
Waning gibbous phase of Mercury: About a few days after its superior conjunction, a less than full, but more than half-illuminated Mercury—a waning gibbous phase of Mercury—appears in the western sky after sunset. Each day, its illuminated area decreases but disk size increases.
Third quarter phase of Mercury: Mercury exhibits its third quarter phase around its greatest eastern elongation from the sun when its phase angle—the angle between the sun, Mercury and Earth—is 90°. During the phase, another half-illuminated Mercury (like a half-moon) appears in the western sky after sunset.
Waning crescent phase of Mercury: About a few days after its greatest eastern elongation, another thin, sickle-shaped Mercury—a waning crescent phase of Mercury—appears in the western sky after sunset. Each day, its illuminated area decreases but disk size increases until it becomes a new Mercury.
References
Geocentric Ephemeris for Mercury : 2026
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