Take a break from the inauguration hoopla. While dancers sway to the music at Washington’s inaugural balls on Monday, the cosmic couple Jupiter and the fattening moon deliver a heavenly waltz: They are less than a degree apart.
Monday evening, find them very high in the east-southeastern sky — almost overhead. In fact, on Monday night, they will be at their closest at 11:30 p.m. Eastern time, 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. On each successive night, the moon sneaks closer.
We live in a three-dimensional solar system, so 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, while the mean distance for Jupiter from the sun, is about 483.8 million miles.
And then there was light: Examining the moon for the next several evenings, you’ll notice it fills out more — and gets a smidgen brighter. Tonight, the seven-day-old moon will be negative 9.8 magnitude (very bright) and tomorrow it will be negative 10.2. Sunday 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. Early last month, 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 Dec 25.
Beyond the Beltway: If you can find a dark sky outside of Washington, you can catch the moon and Jupiter snuggle between the star clusters Hyades (Messier 25), and the Pleiades (Messier 45). Along with the star Aldebaran, the Hyades loiter underneath Jupiter and the moon, while the Pleiades hang out on top.
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 9:52 p.m. (that’s the middle of the transit) according to the Sky and Telescope online Red Spot calculator. You can find the Great Red Spot late tonight, as the transit is centered at 22 minutes past midnight, which is, of course, Saturday morning. Then, 8:13 p.m. on Saturday night.
Virtual observers: In case Monday’s night sky is cloudy or 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 9 p.m. Eastern time. 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.
Sources: The Observer’s Handbook 2013, The Royal Astronomical Society of Canada; Astronomical Calendar 2013, Guy Ottewell, Universal Workshop; Sky and Telescope, EarthSky.