2021, July 15: Evening Celestial Wheel Turns
July 15, 2021: Each evening the moon continues to move eastward with a waxing phase while Venus and Mars dance in the western sky.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 5:29 a.m. CDT; Sunset, 8:24 p.m. CDT. Check local sources for sunrise and sunset times for your location.
The movement of the moon and planets in the western sky demonstrates the intricate, yet delicate, celestial clockwork.
The crescent moon’s phase grows each evening as it moves farther eastward from the sunset point.
Lower in the western sky, Venus is stepping away from Mars toward Regulus. Mars is moving toward the star as well, but at a slower rate.
Forty-five minutes after sunset, set outside and look westward. The moon, 35% illuminated, is nearly one-third of the way up in the west-southwest.
Brilliant Venus is low in the west-northwest. Its visual intensity punches through the colors of evening twilight. At this sky brightness, use a binocular to see dimmer Mars, 1.5° to the lower right of the brilliant planet. The star Regulus is 7.3° to the upper left of Venus. You can either fit Venus and Mars in the same binocular field or just fit Venus and Regulus, Venus to the lower right section of the field, and Regulus to the upper left.
As the sky darkens further, the planets and Regulus are lower in the sky. Possibly Mars and Regulus appear through the dimming light before they set.
The moon is in front of the constellation Virgo. It is 4.1° to the right of Porrima, also known as Gamma Virginis (γ Vir on the chart), and over 18° to the right of Spica. Tomorrow evening the moon is closer to Spica.
Additionally, Venus is farther from Mars and stepping toward Regulus.
Detailed Daily Note: One hour before sunrise, Saturn is nearly 23° above the southwest horizon. Retrograding in Capricornus, Saturn is 2.6° to the lower right of θ Cap. Through a binocular spot 19 Capricorni (19 Cap, m = 5.8), 0.2° to the upper right of the Ringed Wonder. Jupiter is 19.7° of ecliptic longitude to the east (upper left) of Saturn. Jupiter retrogrades in Aquarius, 2.4° to the upper left of ι Aqr, 4.4° below θ Aqr, and 4.4° to the lower right of σ Aqr. With an optical assist of a binocular, spot the Jovian Giant between dim 38 Aqr and 42 Aqr. Fifteen minutes later, Mercury (m = −0.7) – 18° west of the sun – is nearly 5° above the east-northeast horizon and nearly 26° to the lower left of Aldebaran. The sun is in the sky for 5 minutes less than 15 hours. One hour after sunset, the waxing crescent moon (6.0d, 35%) – over 26° above the west-southwest horizon – is 4.1° to the right of Porrima (γ Vir. m = 3.4). Farther westward along the ecliptic, brilliant Venus – 29° east of the sun – is nearly 6° up in the west-northwest, 1.5° to the upper left of Mars and 7.3° to the lower right of Regulus. Saturn rises 55 minutes after sunset, while Venus sets nearly 40 minutes later. Can you find them in the sky together? Through a telescope, Venus is an evening gibbous that is 87% illuminated and only 11.8” across. Jupiter rises 109 minutes after sunset. As midnight approaches, bright Jupiter is over 15° up in the east-southeast, while Saturn is over 21° above the southeastern horizon.
Articles and Summaries
- Venus as an Evening Star
- Venus Evening Star (Summary)
- Mars during 2021 (Summary)
- July Planet Summary 2021 (Summary)
October 26, 2021: Mercury is at its greatest morning appearance for the year. Look low in the east-southeast before sunrise.
October 25, 2021: This morning the bright gibbous moon seems to be caught between the horns of Taurus. Mercury is making its best morning appearance. The planet pack – Venus, Jupiter, and Saturn are in the evening sky.
October 24, 2021: Saturn is at its closest to Jupiter as the Jovian Giant picks up eastward speed. The morning moon and Mercury are visible before sunrise. Brilliant Evening Star Venus, Saturn, and Jupiter are in the sky after sunset.
October 23, 2021: This morning the bright moon is near the Pleiades star cluster. Mercury is making its best morning appearance. In the evening sky, Venus, Jupiter and Saturn are easy to spot.
October 22. 2021: Speedy Mercury is low in the east before sunrise. It is putting on its best morning performance of the year. Arcturus, in the east-northeast, is about the same altitude as Mercury.