SAEDNEWS: According to the U.S. Naval Observatory, the second new moon of December will occur at 5:27 p.m. Eastern Time on December 30 (1:57 a.m. the next day in Iran).
According to SaedNews Science Service, citing Asr-e Iran, a rare phenomenon called the “Black Moon” will occur in the final days of 2024. This term refers to the second new moon within a single calendar month. The U.S. Naval Observatory reports that December’s second new moon will occur at 5:27 p.m. Eastern Time on December 30 (1:57 a.m. the following day in Iran).
A Black Moon describes a double new moon observed within a single month or season. A new moon—or “moonlet”—typically occurs once every lunar orbit around Earth. It marks the stage when the moon passes conjunction with the sun and, on the first or second evening, displays a thin crescent just above the western horizon. The new moon also signals the start of the lunar calendar month.
Sometimes called a Black Moon, a second new moon in a month is comparable to the phenomenon of a “Blue Moon,” which occurs when there are two full moons in a month. Neither term is officially recognized in astronomy. New moons occur when the sun and moon share the same celestial longitude, a position known as “conjunction.” At this stage, the moon is invisible from Earth, as its illuminated side faces away, and it only becomes observable during solar eclipses.
For both amateur and professional astronomers, new moon nights are a gift. The absence of moonlight allows fainter celestial objects to be seen more easily. This is particularly true in winter across many parts of North America, where dry air enhances telescope visibility.
On December 28 at 11:24 p.m. Eastern Time, the moon will be in conjunction with Mercury, appearing roughly six degrees apart. For example, in New York City, Mercury rises at 5:38 a.m. on December 28, followed by the sun at 6:48 a.m. Meanwhile, the moon rises at 5:26 a.m., and by 6:15 a.m., both Mercury and the crescent moon—approximately six degrees above the eastern horizon—can be observed. Mercury will appear to the right of the moon. Their proximity to the horizon makes observation challenging, but the moon can serve as a guide. Observers must look east to witness the conjunction. In Cairo, this event occurs at 6:24 a.m. local time on December 29, with sunrise at 6:50 a.m. and Mercury rising at 5:13 a.m.
On the night of the new moon, Mercury will also be visible in the pre-dawn sky on December 31. Its height in the southeast will be about nine degrees, making it difficult but not impossible to see under clear conditions.
By early evening (around 6 p.m.), Venus and Saturn will appear in the southwestern sky, while Jupiter will be in the east. Jupiter will be positioned to the left of Aldebaran, the brightest star in the Taurus constellation, making identification easier due to the contrast.
On December 31, Jupiter sets at 5:26 a.m., and Mars rises at 6:07 p.m., reaching about 20 degrees above the eastern horizon by 8 p.m. and remaining visible until sunrise.
In the Southern Hemisphere, days are longer. For instance, in Buenos Aires, darkness falls only around 9 p.m., with sunrise at 5:43 a.m. On the pre-dawn hours of December 31, Mercury rises at 4:18 a.m., reaching about seven degrees above the horizon by 5 a.m., similar to northern latitudes.
On December 30, Venus and Saturn are visible in the west. In Buenos Aires, Venus sets at 10:54 p.m., Saturn at 11:44 p.m., and Jupiter becomes visible in the northeast. Mars rises at 9:42 p.m. and takes time to reach sufficient altitude for clear observation, remaining about 18 degrees above the northeastern horizon until 11:30 p.m.
