Mercury joins Venus and Jupiter for five-night planet parade

NASA’s monthly sky-watching guide notes that Mercury will join Venus and Jupiter in the night sky from Thursday, June 11, through Monday, June 15, creating a planet parade visible to the naked eye. The two brighter planets have already been in conjunction since June 9, and Mercury’s appearance adds a rarer element, as the innermost planet is only briefly visible from Earth.

The alignment occurs along the ecliptic, the plane in which the planets orbit the Sun, and while such configurations are not uncommon, seeing three planets together is a notable event for amateur astronomers. The moon will be in a waning crescent phase, reaching new moon on June 14, so it will not outshine the planets.

For observers in the Northern Hemisphere, the best viewing time is after sunset, looking westward toward the horizon. > "You will need a clear view to the west to catch it in the glow of twilight," NASA said in a video. Because Mercury stays low near the horizon, a location free of light pollution and unobstructed by trees or buildings will improve visibility. No telescopes are required, though optical aid can enhance the view.

The planets involved—Mercury, Venus, and Jupiter—are among the five planets visible without equipment, the others being Mars and Saturn.