Prime viewing window for Mercury on June 15
During the evening of 15 June the planet Mercury will attain its maximum eastern elongation, the largest angle it will form with the Sun in this apparition. This places the planet well above the western horizon shortly after sunset, making it accessible to observers at mid‑latitude locations.
The favorable geometry allows amateur astronomers to spot the tiny, bright object with the naked eye or a modest binocular. Because Mercury remains above the horizon for a few hours, its motion can be followed before it sinks back toward the Sun’s glare.
The elongation will be roughly 22 degrees, meaning Mercury becomes visible about two and a half hours after sunset. The optimal window for viewing lies between 20:00 and 22:00 local time, varying with the observer’s longitude.
- Maximum eastern elongation: ~22°
- Visibility: ~2.5 h after sunset
- Best viewing period: 20:00–22:00 local time
After 15 June the elongation will decrease, and Mercury will gradually disappear behind the Sun’s brightness. Those interested should choose a dark site and consider using binoculars to appreciate the planet’s crescent phase and subtle motion across the sky.