2021, July 8: Crescent Moon, Mercury, Jupiter, Saturn

July 8, 2021:  The best morning to see Mercury is with the thin crescent moon this morning.  Starting with a binocular, look for them in the east-northeast about 45 minutes before sunrise.  Jupiter and Saturn are easy to see in the southern sky about one hour before sunrise.

2021, July 8: Forty-five minutes before sunrise, the crescent moon is 4.4° to the left of Mercury.
Chart Caption – 2021, July 8: Forty-five minutes before sunrise, the crescent moon is 4.4° to the left of Mercury.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:24 a.m. CDT; Sunset, 8:28 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

This is the best morning to see Mercury.  The thin crescent moon is 4.4° to the left of the speedy planet.

Mercury is making its 2021 summer morning appearance.  The planet is low in the east-northeast during morning twilight. Find a clear horizon in that direction.  It nearly always shows itself during twilight and rarely is visible in a dark sky from mid-northern latitudes.

2021, July 8: Through a binocular the crescent moon, only 2% illuminated, is 4.4° to the left of Mercury.
Chart Caption – 2021, July 8: Through a binocular the crescent moon, only 2% illuminated, is 4.4° to the left of Mercury.

Look for the crescent moon about 45 minutes before sunrise.  The thin sliver is only 2% illuminated.  A binocular provides an optical assist to locate the lunar slice.  Hold the binocular so that the moon is toward the left portion of the field of view.  Mercury is to the right in the same field.  After locating them through the binocular, can you see them without the optical assist?

During the month, Mercury is about 5° up in the sky in the same direction as this morning, and it brightens each morning. The moon is not there to guide you to the planet. Later in the month, it appears lower and brighter as it disappears back into bright twilight.  What is the last date that you can see Mercury?

2021, July 8: Bright Jupiter and Saturn are in the southern sky before sunrise. The star Fomalhaut is in the same region of the sky as the planet duo.
Chart Caption – 2021, July 8: Bright Jupiter and Saturn are in the southern sky before sunrise. The star Fomalhaut is in the same region of the sky as the planet duo.

A little earlier, about one hour before sunrise, two bright morning planets are visible.  Jupiter and Saturn are in the southern sky.

Saturn is nearly 20° to the lower right of Jupiter.  It is retrograding in Capricornus.  Earth passes between the Ringed Wonder and the sun on August 2, followed by Jupiter’s opposition with the sun on August 19.

Jupiter is about 20° to the upper right of the star Fomalhaut, “the mouth of the southern fish.” Not as bright as Saturn, the star is lower in the sky than the Ringed Wonder.

Detailed Daily Note: One hour before sunrise, Jupiter is over 36° above the southern horizon and west of the meridian.  Notice Fomalhaut (α PsA, m = 1.2), over 20° to the lower left of Jupiter and slightly east of the meridian.  Jupiter is retrograding in Aquarius, 2.8° to the upper left of ι Aqr, 4.2° to the lower left of θ Aqr, and 4.0° to the lower right of σ Aqr.  Saturn is 19.7° to the lower right of Jupiter and 2.2° to the lower right of θ Cap.  The Ringed Wonder is retrograding in Capricornus.  Fifteen minutes later, the moon (27.9d, 2%) is nearly 6° up in the east-northeast. Mercury (m = −0.1) is 4.4° to the right of the waning crescent moon.  One hour after sunset, Venus is nearly 6° up in the west-northwest, 2.6° to the lower right of Mars.  Their conjunction occurs in four evenings.  Venus is over 15° to the lower right of Regulus (α Leo, m = 1.3). Saturn rises 80 minutes after sunset.  Jupiter follows about 50 minutes later.  As midnight approaches, Saturn is about 18° up in the southeast, while Jupiter is over 10° above the east-southeastern tree line.

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