"Observers will see an eye-catching grouping of three bright objects that includes Venus, the brightest planet; Jupiter, the second brightest planet [as seen from Earth]; and the waning crescent moon—all against a rich backdrop of stars," said Anthony Cook, astronomer at the Griffith Observatory in Los Angeles.
Already dominating the early morning skies for the past month, Venus and Jupiter on July 15 will form a spectacular wide triangle formation with a thin sliver of the moon. (Get more night-sky news.)
The so-called conjunction—when celestial objects appear to get close to each other in the sky—isn't considered rare, since both planets and the moon follow the same pathway in Earth's sky, known as the ecliptic.
"Venus and Jupiter appear near each other about once per year, but because the moon sweeps through the entire ecliptic each month, it will also appear near Venus and Jupiter while they are still in the vicinity of one another."
As a result, a Venus-Jupiter-moon conjunction occurs about once a year.
Sky Show With a Side of Bull
For Sunday's event, sky-watchers will have get up early—at least 30 minutes before local sunrise—to catch sight of all the celestial players before the sky gets too bright, Cook said. (See moon and sunset pictures.)
Keen-eyed observers can also catch sight of one of the brightest stars in the sky joining the celestial gathering before dawn sets in.
Just to the right of Venus will be the orange-hued Aldebaran—the eye of Taurus, the bull constellation. (Test your solar system knowledge.)
While this cosmic grouping can be enjoyed with the unaided eyes, the event makes for a great opportunity to get a closeup view of these objects through binoculars and telescopes.
"Binoculars—or even better, a telescope—will show the slender crescent phase of Venus and the cloud patterns and four brightest moons of Jupiter, as well as lunar craters and earthshine [sunlight reflected off Earth] illuminating the night side of the moon," he said.
"Any gathering of bright celestial objects tends to attract our attention, but adding the presence of the moon and the bright constellation Taurus, the Bull, will only add to this sky show."