Universe Today
Early risers on April 25th might see a rare quadruple bunching of the Moon and planets at dawn.
Occasionally, the Universe seems to literally smile upon us. If skies are clear Friday morning on April 25th, early rising sky watchers may witness a rare scene, as brilliant Venus and fainter Saturn form the ‘eyes’ and a thin crescent Moon nearby completes the ‘grin’ low to the east at dawn.
The planetary trio involved in Friday’s complex celestial tango includes (from brightest to faintest) -4.8 magnitude Venus, +0.3 magnitude Mercury, and +1.2 Saturn.
Venus just passed four degrees from Saturn this week on April 24th. Venus itself had a memorable conjunction with the Sun on March 23rd and is now racing towards greatest elongation just over 46 degrees west of the Sun on June 1st. Venus also reached greatest brilliancy for this apparition this week on April 24th. You can actually see Venus in the daytime… if you know exactly where to look for it. Make sure the Sun is safely blocked from view, and the nearby crescent Moon on the 25th will help guide you on your quest. Can you follow the pair up into the daytime sky, post-sunrise?
The Moon smiles with Venus and Mars in February 2015. Credit: David Blanchflower.
The fainter ‘eye’ in the smiling face is the planet Saturn. Saturn’s ring’s just passed edge-on for 2025 in March. In the telescope, Saturn just presents the merest thread of its rings this weekend. Saturn is a relatively tough one to spot with the naked eye this week, as it’s currently five full magnitudes or a hundred times fainter than Venus.
Next, don’t forget Mercury, the lowest of the three. Mercury just passed greatest elongation 27 degrees west of the Sun on April 21st, and is now taking the plunge past the Sun towards the evening sky.
Even +7.8th magnitude Neptune gets involved...although you’ll need binoculars or a telescope to pick off the faint and distant ice giant low in the dawn murk.
The Moon photo-bombs the scene starting on the morning of the 25th as it slides between Saturn and Venus, just missing the pair. The thin old waning Moon completes the wide-eyed ‘smile,’ for viewers across Europe and North America.
Follow that Moon as it passes Mercury and gets ever lower to the horizon on the morning of the 26th, en route to New on the 27th. The hunt is then on to recover the slim waxing crescent Moon on the evening of Sunday, April 27th into Monday the 28th. First sightings favor central Asia into Europe.
A slender Moon from October 2018, less than 22 hours past New. Credit: Robert Sparks.
‘Smiling Conjunctions’: Past, Present...and Future
True double occultations involving the crescent Moon and a naked eye planet pair, or a planet and a bright +1st magnitude star are truly rare affairs. There are only four bright stars to choose from along the Moon’s path: Aldebaran, Regulus, Spica and Antares. The Moon itself is only half and angular degree wide, and it covers the span of its own diameter once per hour.
The Moon meets Venus and Mars in February 2015, as seen from Denmark, Maine. Credit: Dave Dickinson.
These means that such ‘smiling emoticon triple conjunctions’ often happen over remote locales, or occur in the daytime sky or near the Sun. Looking out over the coming millennium, I see 104 potential events, roughly one per decade.
One of the best in recent memory involved the crescent Moon, Venus and Jupiter 27 years ago this week on the morning of April 23rd, 1998, although you would have had to have been standing on Ascension Island in the Atlantic to see it. Olivier Staiger documented this once-in-a-lifetime view:
Two views of the rare 1998 double occultation event, captured by Olivier Staiger. (@OlivierStaiger on Instagram). Used with permission.
The good news is, we do have another bizarre grouping coming right up this year on September 19th involving the crescent Moon, Venus and Regulus… though you’ll have to journey to remote Arctic Russia to see it.
The September 19th event. Credit: Stellarium/Dave Dickinson
To be sure, these sorts of bizarre celestial scenes are of limited scientific value… but they’re beautiful and unique to see, proof that if you watch the sky long enough, you might just see something fantastic and strange. At very least, its worth setting your alarm for this Friday.
