Don’t miss Jupiter and its 5 Galilean satellites shine near the crescent moon tonight

Some celestial events are worth getting up early for – or perhaps staying up late for.

Early risers and/or night owls on Flag Day (Wednesday) morning, given fair weather and clear skies, will be treated to a lovely “celestial tableau” low in their eastern sky as the brilliant planet Jupiter hovers close to the right of a slender waning crescent moon; they will be by far, the two brightest objects visible in the predawn sky and will command instant attention wherever the sky is reasonably clear.

Jupiter currently rises about two and a half hours before the sun — around 3 a.m. local daylight time — when at magnitude -2.1, it outshines everything but the moon (negative magnitudes indicate a bright object in the sky). The gas giant is currently in the constellation Aries, where it will remain through the balance of the year. In the days and weeks to come, Jupiter will rise progressively earlier as well as appearing to noticeably brighten as Earth speeds along in orbit, closing the distance between our two worlds. As bright as Jupiter may be now, by the time it arrives at opposition to the sun in early November it will appear to shine more than twice as bright.

Related: Night sky, June 2023: What you can see tonight [maps]

An ashen glow

Wednesday morning finds the moon, 14% illuminated and positioned two degrees from Jupiter. Your thumb held at arm’s length measures roughly 2-degrees, so on Wednesday morning you can find Jupiter, shining like a brilliant silvery “star” with a steady glow, will stand about “one thumb” to the right of the moon.

The view will likely be even more enhanced by the effect of “Earthshine” on the moon. It is an effect that allows you to see the full globe of the moon, its darkened portion glowing with an ash-gray hue interposed between the sunlit crescent and not much darker sky. This vision is sometimes called “the old moon in the young moon’s arms.”

Leonardo da Vinci (1452-1519) was actually the first to recognize it as Earthshine, faint bluish-gray light from Earth reflected back to the moon. The Earth’s light of course is reflected sunlight, so Earthshine is really sunlight which is reflected off Earth to the moon and reflected back to Earth.

Binoculars will bring out the Earthshine effect even more than with the unaided eye and will impart a three-dimensional effect to the moon. In some binoculars, you’ll even be able to fit both the moon and “Big Jupe” in the same field of view a  —  sight well worth rising early to see!

If you need some new optics to help you take in sights like these, our guide to the and best binoculars and the best telescopes are a great place to start.

And if you’re looking to take photos of the night sky, check out our guide on how to photograph the moon, as well as our best cameras for astrophotography and best lenses for astrophotography.

Don’t forget Galileo’s moons!

And while you’re using the binoculars — or even better, perhaps a small telescope — be sure to look for the famous Galilean satellites; the four large moons that circle Jupiter that were first seen by Galileo through his crude telescope in 1610. On this particular morning, should you be looking at Jupiter through a pair of steadily held binoculars or a telescope, you’ll be able to see all four satellites.

You’ll find three on one side of Jupiter — going outbound from the big planet, Io, Europa and Calisto — while on the other side, all by itself, will be the fourth satellite, Ganymede.

So, including our own moon on this particular morning, you’ll get five moons for the price of one!

Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers’ Almanac and other publications.