The Washington Post
While dancers sway to the music at inaugural balls on Monday, the cosmic couple Jupiter and the fattening moon deliver a heavenly waltz: They are less than a degree apart.
On Monday evening, find them very high — almost overhead — in the east-southeastern sky. In fact, on Monday night, they will be at their closest at 8:30 p.m., according to Tony Flanders and Alan MacRobert, editors at Sky &Telescope magazine.
EarthSky says this is the closest moon-Jupiter conjunction until 2026.
But you don’t have to wait until Monday to see them convene. tonight, like an airplane on final approach, the waxing moon slides through the sky toward the Jovian orb.
Jupiter and the moon are not really next to each other. It just looks that way. The mean distance of the moon is about 239,000 miles to Earth, and the mean distance for Jupiter from the sun is about 483.8 million miles.
Examining the moon for the next several evenings, you’ll notice it fills out more — and gets a smidgen brighter. Today will be negative 10.5 magnitude and Monday will be negative 10.8 magnitude. (Incidentally, the moon is officially full on Saturday, Jan. 26, at 11:38 p.m., when it reaches negative 12.3 — which is ultra bright.)
Jupiter’s brightness remains constant through the weekend at negative 2.6 magnitude, very bright. Last Month, in early December, the planet was a few shades brighter at negative 2.8 (very bright), since it reached a position opposite the sun — from Earth’s perspective. Jupiter and the moon last converged on Christmas night Dec 25.
For telescope owners, treats abound: If we have clear skies on Monday, the Jupiter’s famed Great Red Spot transits the Jupiter meridian at mid-evening at 6:52 p.m. (that’s the middle of the transit), according to the Sky and Telescope online Red Spot calculator.
If you want to see close-ups on Jupiter and the moon from the comfort of your computer, the Slooh Space Camera will have an Internet broadcast live on Slooh.com, on Monday, starting at 6 p.m.
The free broadcast will concurrently feature real-time discussions with Slooh president Patrick Paolucci, Astronomy magazine columnist Bob Berman, and astro-imager Matt Francis of the Prescott Observatory.
Viewers can watch live on their PC or iOS/Android mobile devices. Viewers will be able to see Jupiter’s Great Red Spot.