The grinning Moon slides by Regulus and Venus later this week, in a complex event.
Sometimes, it seems as if the Universe is literally smiling down upon us. If skies are clear this coming Friday, September 19th, be sure to wake up early to catch a bizarre celestial scene as Venus, Regulus, and the slim crescent Moon huddle together in the eastern dawn.
This triple play is a complicated one, involving one of the best conjunctions for 2025.
Related: Stunning ‘Blood Moon’ Lunar Eclipse Seen by Millions Across 3 Continents
First up, let’s consider the apparent scene: the Moon is a slender 5% illuminated, waning crescent on the morning of the 19th, 27 degrees west of the Sun.
Meanwhile, Venus is 89% illuminated, presenting an 11″ disk. Venus has spent the majority of the year dominating the dawn sky.
Finally, +1.3 magnitude Regulus, the lucida of the constellation Leo the Lion fills out the scene.
Though the trio fits well inside a one-degree circle in the sky, they’re actually a good study in astronomical distance. The Moon is only 385,000 kilometers (1.3 light-seconds) away, while Venus is just over 12 light-minutes distant. Finally, far-flung Regulus is 78 light-years out, far beyond our Solar System.
This makes for a grinning ’emoticon conjunction,’ with Regulus and Venus as the dazzling eyes, while the slice of the Moon completes the smile. What’s more, the celestial dance of each of these objects provides an interesting event in its own right.
First up, the Moon actually occults (passes in front of) Regulus for a remote swatch of northern Siberia on the 19th. This is part of an emerging cycle of occultations of the star by the Moon, running out to January 24th, 2027.
The occultation of Venus by the Moon will probably be the largest general interest event of the grouping. The extreme northwestern Canadian Arctic will see the occultation transpire under dark to twilight skies. Meanwhile, the North Atlantic and all of continental Europe down into northern Africa will see the Moon occult Venus in the daytime.
Viewers outside of the footprint can still attempt a worthy challenge and try to spot Venus near the slim waning crescent Moon in the daytime. Simply following the pair up through the dawn post-sunrise is your best bet. Be sure to block the dazzling Sun safely out of view behind a hill or building while attempting this feat of visual athletics.
Can you see Regulus nearby as well? A telescope or binoculars can help with your daytime quest.
The grouping also completes a rare double occultation. It’s unlikely anyone will witness this remote event, however. The pair is 30′ apart right around 12:30 Universal Time (UT) on the 19th, and the two will only be covered by the Moon under bright twilight skies as seen from a remote patch north of Dudinka, Russia in Arctic Siberia.
But what a fine sight it would be, as both Venus and Regulus skim through those lunar peaks and valleys!
frameborder=”0″ allow=”accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share” referrerpolicy=”strict-origin-when-cross-origin” allowfullscreen>Generally speaking, the event will look more like a ‘smile’ the farther northwest in North America you are. The eastern US, for example, sees Venus, Regulus, and the Moon forming a straight line from the south running northward. The Yukon and Alaska get the very best view, with a smiling lunar visage punctuated by the staring eyes of Regulus and Venus under darker twilight skies.
How rare is such a scene? Well, getting such a tight grouping within half-a-degree circle (the apparent width of the Moon) is no mean feat. We’ve got five naked-eye planets ( Mercury, Venus, Mars, Jupiter, and Saturn) plus four bright stars near the path of the Moon: Aldebaran, Spica, Antares, and Regulus.
Plus, to get our ‘smile’ right, you’d need the Moon somewhere between Last Quarter and First Quarter phase. Plus, the Moon seems to move its own diameter once every hour.
I realized some years back that such events would probably involve occultations of two bright objects by the Moon spaced an hour apart. This is fairly easily searchable in a program such as Occult 4.2. Hey, it’s what we do for fun, especially when it’s cloudy outside.
Looking out over the current millennium to the year 3000 AD, we found 85 such events.
frameborder=”0″ allow=”accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share” referrerpolicy=”strict-origin-when-cross-origin” allowfullscreen>Of course, many are close to the Sun, while others are near a Full Moon, or occur under a daytime sky. Probably one of the very best events for the ages occurred not that long ago on the morning of April 23rd, 1998, when the Moon occulted Venus and Jupiter (!) as seen from Ascension Island in the South Atlantic.
Olivier Staiger actually managed to document the event:
Such a sight is rare indeed. The next one we found isn’t until October 15th, 2036, also involving Regulus (this time, paired with Saturn):
Finally, follow that Moon, as it’s headed for the final eclipse of 2025 with a deep partial eclipse for New Zealand, the South Pacific, and Antarctica coming right up on September 21st.
More to come on that this week. For now, be sure to enjoy Friday’s rare emoticon conjunction. Perhaps this is proof that the Universe does indeed have a sense of humor.
This article was originally published by Universe Today. Read the original article.