2021, July 18: Planetary Platter

July 18, 2021: All five bright planets – Mercury, Venus, Mars, Jupiter, and Saturn – are visible during the nighttime hours. Jupiter, Saturn, and Mercury in the sky before sunrise.  Venus, Mars, Jupiter, and Saturn are in the sky after sundown.

2021, July 18: Jupiter and Saturn are in the southwestern sky before sunrise. The star Fomalhaut is to the lower left of Jupiter.
Chart Caption – 2021, July 18: Jupiter and Saturn are in the southwestern sky before sunrise. The star Fomalhaut is to the lower left of Jupiter.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:32 a.m. CDT; Sunset, 8:22 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

Morning Sky

One hour before sunrise, bright Jupiter and Saturn are in the southwestern sky.  Jupiter is over one-third of the way up in the south-southwest.  It is brighter than all the stars in this morning’s sky.  It is retrograding in Aquarius, an illusion as Earth catches and passes between the sun and the outer planets, known as opposition.

Saturn is at opposition on August 2, followed by Jupiter 17 days later.

Saturn is brighter than nearly all the stars in the morning sky except for Jupiter, Mercury, Arcturus, and Vega.

The Ringed Wonder is nearly 20° to the lower right of Jupiter.  It is retrograding in Capricornus.

The star Fomalhaut, “the mouth of the southern fish,” is to the lower left of Jupiter.

2021, July 18: Mercury is low in the east-northeast before sunup.
Chart Caption – 2021, July 18: Mercury is low in the east-northeast before sunup.

About 15 minutes later, Mercury is high enough to be seen in the east-northeast.  Find a clear horizon to see it.  It is bright enough to poke through the growing twilight.  A binocular is helpful to first locate it.

Evening Sky

Brilliant Venus continues to shine low in the western sky after sunset.  Nearly a week after its conjunction with Mars, the brilliant planet is moving toward a conjunction with Regulus in three evenings.

Step outside at about 45 minutes after sunset.  Likely, the moon is the celestial object that first attracts your attention.  More on the waxing gibbous moon a little later.  Look low in the west-northwest for brilliant Venus.

2021, July 18: This binocular view reveals Regulus and Mars with brilliant Mars after sunset.
Chart Caption – 2021, July 18: This binocular view reveals Regulus and Mars with brilliant Mars after sunset.

Venus, Mars, and Regulus tightly fit into the same binocular field.  First locate Venus in the binocular.  With Venus at the center of the field of view, Mars is to the lower right in the field, while Regulus is to the upper left.

Venus is 3.2° to the upper left of Mars and 3.8° to the lower right of Regulus.

2021, July 18: The moon is to the upper left of Zubenelgenubi.
Chart Caption – 2021, July 18: The moon is to the upper left of Zubenelgenubi.

Back to the moon.  The lunar orb is 69% illuminated and about one-third of the way up in the sky above the south-southwest horizon.

The moon is 3.3° to the upper left of Zubenelgenubi, “the southern claw of the scorpion.”

As Venus appears lower in the western sky this evening when the sky darkens further, Saturn – then Jupiter – rises in the east-southeast.

2021, July 18: Around midnight, Jupiter and Saturn are in the southeastern sky.
Chart Caption – 2021, July 18: Around midnight, Jupiter and Saturn are in the southeastern sky.

By 11:45 p.m. CDT (in the Chicago area) – about 3.5 hours after sunset – Saturn and Jupiter are in the east-southeastern sky.  At this hour, Jupiter is over 17° above the southeastern horizon.  Saturn, over 22° up in the southeast, is to Jupiter’s upper right.

The giant planets appear farther south as the night progresses, shining from the southwestern sky tomorrow morning before sunrise.

Detailed Daily Note: One hour before sunrise, bright Jupiter is nearly 34° above the south-southwestern horizon.  The Jovian Giant is retrograding in Aquarius, 2.2° to the upper left of ι Aqr, 4.5° below θ Aqr, and 4.7° to the lower right of σ Aqr. The planet is now well-past the diagonal line from 38 Aqr to 42 Aqr. After Jupiter resumes is eastward trek, it passes between the two stars again during early January 2022. Saturn, in Capricornus, is 19.7° to the lower right of Jupiter.  Retrograding, it is 2.8° to the lower right of θ Cap.  Fifteen minutes later, Mercury (m = −1.0) is about 4° up in the east-northeast. Forty-five minutes after sunset, brilliant Venus is over 8° up in the west-northwest, 3.2° to the upper left of Mars and 3.8° to the right of Regulus.  At this sky brightness use a binocular to see Mars and Regulus with Venus.  The trio tightly fits into the same binocular field of view.  One hour after sunset, look for Zubenelgenubi, 3.3° to the lower right of the waxing gibbous moon (9.0d, 69%).  Saturn rises 45 minutes after sunset.  Venus sets 48 minutes later.  The gap between Jupiter rising and Venus setting is six minutes.  The Venus – Jupiter opposition occurs in three evenings.   As midnight approaches, the bright moon is about 14° above the southwest horizon.  Jupiter is over 17° up in the southeast.  Saturn, to the upper right of the Jovian Giant, is over 22° up in the southeast.

Articles and Summaries

2021, May 13: The crescent moon is 3.2° to the upper left of Mercury.

2021, August 9: Evening Moon, Mars

August 9, 2021: After the New moon yesterday morning, the crescent moon appears in the evening sky during bright twilight near Mars.

2021, May 13: Brilliant Venus, Mercury, and the crescent moon in the evening sky.

2021, August 3: Four Evening Planets: Venus, Mars, Saturn, Jupiter

August 3, 2021:  Four planets appear in the evening sky.  Brilliant Evening Star Venus and dim Mars are in the west after sunset.  A little later during the evening, Saturn and Jupiter are easily visible in the southeast.

Saturn (NASA)

2021, August 2: Saturn at Opposition

August 2, 2021: Saturn is at opposition with the sun.  Earth is between the sun and the planet.

2020, July 17: The crescent moon appears near Venus before sunrise. The night portion of the moon is gently illuminated by earthshine.

2021: August 1 – 6: Morning Moon, Bright Stars

August 1 – 6, 2021:  The morning moon wanes toward its New moon phase in the eastern sky.  It passes the bright stars that are prominent in the evening sky during the winter season in the northern hemisphere.  The stars have been making their first appearances in the morning sky during summer.  At this hour, Procyon and bright Sirius are the last stellar duo to appear.

2021, July 8: The flowers celebrate summer.

2021, August 6: Summer’s Midpoint

August 6, 2021:  In the northern hemisphere, summer’s midpoint occurs today at 6:27 p.m. CDT.



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