Skywatchers who get up early on Monday, Sept. 16, 2025, and have a clear sky will see a conjunction of a beautiful crescent moon and Jupiter, with two bright stars very close by. Castor and Pollux, two bright stars relatively close to the sun, are known as the twins of the constellation Gemini.
The four objects will look at their best about 90 minutes before sunrise across North America on the morning of Monday, Sept. 16, 2025. Look low in the east before dawn.
A waning crescent moon, around 28%-lit, will look spectacular just a degree from Jupiter, either to the naked eye or through binoculars.
Just to the left of the moon will be the stars Castor (above) and Pollux (below), with all four forming a flattened diamond shape as seen from North America.
From Europe, the moon will be a little higher in the sky, creating a more pronounced diamond shape.
Each of the four objects — the moon, Jupiter, Castor and Pollux — will appear to be about four degrees apart. That's the width of three fingers held at arm’s length.
All four objects will be visible to the naked eye, but will also fit into the field of view of binoculars. The crescent moon is a spectacular object in binoculars, with the terminator — the dividing line between day and night on the moon ‚— where to look for shadows and craters. It's also worth pointing any pair of binoculars at Jupiter to see its largest moons, Ganymede, Europa, Callisto and Io. These four moons can be easily seen as points of light.
This pairing of the crescent moon and Jupiter makes for a captivating sight, but the nearby presence of Gemini’s famous twin stars will make this an even more beautiful panorama. To the moon’s lower left, orange-tinted Pollux — just 34 light-years from the solar system — will act as one corner of the diamond. Slightly above it, to the moon’s upper left, lies yellowish Castor, which is about 51 light-years distant. Binoculars may provide a sharper view of the contrast in color between Castor and Pollux.