October 31, 2021: There is no Halloween Full moon this year, and the phase is not close. The crescent moon is in the morning sky. Mercury is low in the east-southeast before sunrise. The planet pack – Venus, Saturn, and Jupiter – gleams in the evening sky.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 7:22 a.m. CDT; Sunset, 5:46 p.m. CDT. Check local sources for sunrise and sunset times for your location.
Each year during Halloween, images have the symbols of the fall season – goblins, pumpkins, ghosts, jack-o-lanterns, witches, and Full moons.
The moon returns to the same place in the sky with a repeating moon phase every 19 years (6939.6884 days). This is known as the Metonic cycle, attributed to the Greek astronomer Meton around the year 430 BC.
This interval can be used to predict eclipses. For example, the upcoming lunar eclipse on November 19 occurs again on the same date in 2040. Because of the fraction of the day noted above, a different part of the world sees the total eclipse in that year. This year, the western hemisphere is treated to a nearly total eclipse. In 19 years, the eclipse is widely visible across Asia and Africa.
Based on this cycle, the next Halloween Full moon is in 2039.
So, no Full moon this year, but step outside before sunrise to see the thin crescent in the eastern sky before sunrise.
The crescent moon seems to hang in the eastern sky before sunrise. The phase is 25% illuminated and in an ideal phase and place for a time exposure photograph of earthshine – the gentle light on the nighttime portion of the moon from sunlight reflected from Earth’s oceans, clouds, and land.
The lunar slice is nearly 6° to the upper right of Chertan, in the haunches of Leo. Use a binocular to see the star and to better spot the earthshine on the moon.
Mercury is receding into brighter twilight. Forty-five minutes before sunrise, it is 7.0° up in the east-southeast.
Use a binocular to attempt to spot Spica, 4.8° to the lower right of the planet. Spica is making its first morning appearance (heliacal rising) in the southeastern sky before sunrise. This is a challenging observation until the star is higher in the sky during the next several mornings.
Arcturus – in the east-northeast- is higher than Mercury, over 30° to the upper left of the planet.
Brilliant Evening Star Venus is about 12.0° up in the southwest – nearly 7° to the right of Alnasl, “the point of the arrow” of Sagittarius. Venus steps into the constellation in two evenings.
Each evening the planet is higher in the sky after sunset. For those who benefit from shade trees in their western view, they have been challenged to see the planet. With leaves falling at the mid-northern latitudes and the planet higher in the sky, brilliant Venus is becoming easier to see without many obstructions.
Venus sets this evening at 138 minutes after sunset.
As Venus shines from the southwest, Saturn is about one-third of the way up in the sky, over 40° to the east of Venus. Bright Jupiter is over 15° farther eastward from Saturn.
Both planets are slowly moving eastward compared to the stars in Capricornus. During the next several evenings, note Jupiter’s place compared to Deneb Algedi.
Detailed Daily Note: One hour before sunrise, the moon (25.0d, 25%) is nearly halfway up in the east-southeast, 5.9° to the upper right of Chertan (θ Leo, m = 3.3), in the haunches of Leo. Fifteen minutes later, Mercury is 7.0° up in the east-southeast, 4.8° to the upper left of Spica (α Vir, m = 1.0). This is a challenging observation. Spica is quite low and making its first appearance in the morning sky. Forty-five minutes after sunset, Venus is 12.0° up in the southwest, 6.7° to the right of Alnasl (γ Sgr, m = 3.0). Saturn is 41.5° of ecliptic longitude east (left) of Venus. The Ringed Wonder is nearly 29° up in the south. Jupiter – nearly the same altitude as Saturn – is 15.4° of ecliptic longitude east of the Ringed Wonder. Two hours after sunset, Saturn is nearly 28° up in the south-southwest, 1.2° below υ Cap. Jupiter – over 33° up in the south and slightly east of the meridian – is 3.5° to the lower right of μ Cap, 1.9° to the upper right of Deneb Algedi, and 1.5° above Nashira.
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