Mercury is the innermost planet in our solar system. As a result, it always appears very close to the sun in our sky. Most of the time, it disappears in the sun’s glare.
Mercury is visible for only two to three weeks on the western horizon after sunset or on the eastern horizon before sunrise.
Mercury after sunset in July 2025
Mercury will reach its greatest eastern elongation on July 4, 2025 – its maximum angular distance from sunset. At that time, the planet will be 25.9°E from sunset.
After the greatest eastern elongation, Mercury will rapidly approach the sunset glare as it moves towards its sweep between the sun and Earth on August 1, 2025 – its inferior conjunction position.
When to see Mercury: Mercury will be visible from mid-June 2025 through early July 2025 in the evening sky.
Where to look: Look near the western horizon (in the sunset direction) around 45 minutes after sunset for Mercury.
Brightness of Mercury: After emerging in the evening sky in mid-June, Mercury’s brightness will rapidly decrease until it reaches its inferior conjunction position (i.e., its new phase) on August 1, 2025, when the illuminated side of the planet (i.e., the day side) completely turns away from us.
Mercury will shine with a magnitude of -0.5 in mid-June and with a magnitude of +0.7 on the evening of July 4, 2025.
Visibility through the naked eye: Mercury will be easily visible to the naked eye if you have a clear view of the western horizon.
Visibility through a telescope: Mercury will appear 40% illuminated (nearly in its third quarter phase) and 8.2 arcseconds in diameter on its greatest eastern elongation (on the evening of July 4, 2025).
Thereafter, Mercury will become thinner and larger day by day until it reaches its inferior conjunction position.
Visibility throughout the globe: Mercury’s greatest eastern elongation in July 2025 will favor observers in the southern hemisphere.
In the southern hemisphere, Mercury will appear higher in the sky after sunset due to the higher slope of the ecliptic, making the planet easier to observe.
Mercury at greatest eastern elongation
Mercury’s greatest eastern elongation means its maximum angular distance to the east from the sun.
Mercury’s greatest eastern elongation marks the best time to observe the planet on the western horizon after sunset, as the planet rises as late after sunrise as possible and sets as late after sunset as possible.
Mercury appears nearly in its third quarter phase in the sky at its greatest eastern elongation.
How often does Mercury reach its greatest eastern elongation?
Mercury takes about 116 days to orbit the sun with respect to Earth, called the synodic period of Mercury.
So Mercury reaches its greatest eastern elongation once every 116 days, or 3-4 times a year.
A comparison of elongations
Mercury’s greatest elongations are different from each other.
Mercury can reach a maximum of 28°E from sunset and a minimum of 18°E from sunset at its greatest eastern elongation.
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