Mercury’s June 15 Greatest Elongation Illuminates 2026 Night Sky

On June 15 2026 Mercury reaches its greatest eastern elongation, appearing about 25° east of the Sun at magnitude 0. It will be visible in the western twilight after sunset, positioned in the constellation Gemini, and will remain bright enough to be seen with the naked eye before slipping toward the horizon later in the month and disappearing near inferior conjunction on July 13.

A week earlier, on June 9, the two brightest naked‑eye planets, Venus and Jupiter, will pass in close conjunction, creating a striking double‑planet display after sunset. The crescent Moon will sit nearby on June 16‑17, and the bright star Arcturus will rise high in the south, a celestial marker historically used by Polynesian navigators in the Hawaiian region. The night‑sky events are observable across the United States and the United Kingdom, offering both casual stargazers and astronomy enthusiasts a notable June sky show.