As the summer solstice passes, nights gradually lengthen, providing improved conditions for stargazing through July. By the end of the month, truly dark skies will allow for clearer views of the summer Milky Way, particularly in southern regions where the dense star clouds and nebulae around the galactic center in Sagittarius and Scorpius are most prominent.
Early evening offers several notable celestial sights during the long twilight. Among the earliest to become visible is the Plough, which reaches its highest point above the horizon at dusk throughout July. Following the curve of its handle westward leads to Arcturus, a bright orange supergiant star that stands out near the western horizon.
The most striking feature of July’s evening sky is the Summer Triangle, a large asterism rising high in the east. This recognizable formation consists of three bright stars: Altair in Aquila, Vega in Lyra, and Deneb in Cygnus. Deneb is particularly luminous and located over a hundred times farther from Earth than the other two stars, making it a massive supergiant.
Nestled within the bounds of the Summer Triangle are two smaller constellations visible under dark skies. Sagitta, known as the arrow, has a distinctive fork shape, while Vulpecula, the fox, contains comparatively faint stars. Vulpecula was introduced in the 17th century by the astronomer Johannes Hevelius, who originally named the constellation Vulpecula cum Anser, or fox and goose, though the latter is no longer recognized separately.
Within Vulpecula lies the asterism Collinder 399, commonly called the Coathanger. This grouping of stars, shaped like a coathanger, is not a true star cluster but remains a notable feature for amateur astronomers using binoculars.
Planetary visibility is limited this month. Venus, currently in Leo and moving toward its greatest eastern elongation next month, remains low on the western horizon after sunset, appearing about ten degrees above the horizon. Atmospheric turbulence can cause its light to scintillate, creating a flashing, color-changing effect often captured by astrophotographers.
Saturn, situated in Pisces, can be seen in the pre-dawn sky, rising before midnight by month’s end and gradually climbing higher. Observers can spot it near the last quarter moon during a conjunction on July 7 and 8, with Saturn appearing as the brightest object near the Moon.
The Moon features a new moon on the morning of July 14, offering a challenge to observe the slender crescent that evening low in the northeast shortly after sunset. Clear skies and binoculars will aid in spotting the faint crescent, which lies close to the sun, about six degrees away beneath the horizon.
July also marks the prime period for observing noctilucent clouds—high-altitude ice clouds found in the mesosphere approximately 80 kilometers above Earth. These clouds remain illuminated by the sun for a few hours after sunset and before sunrise, even while the ground is in darkness. They often display a striking blue or purple glow, comparable in beauty to auroras. Reports indicate these displays may be increasing in frequency, though the exact reasons remain under investigation. Skywatchers are encouraged to scan the northwest horizon for these elusive night-shining clouds.