May 29, 2021: Three planets are in the evening sky. Brilliant Venus is low in the west-northwest after sunset. Speedy Mercury is leaving the sky after its best evening performance of the year. It is below Venus. Mars is higher in the western sky, in Gemini to the lower left of Pollux.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 5:20 a.m. CDT; Sunset, 8:17 p.m. CDT. Check local sources for sunrise and sunset times for your location.
One evening after their close conjunction, Mercury is 1.2° below Venus. Forty-five minutes after sunset, the brilliant planet is about 6° up in the west-northwest. Find a clear view of the horizon in that direction. A hillside or elevated structure can help with the observation.
Mercury’s brightness is fading quickly as it is rapidly departing the evening sky. Use a binocular to see the speedy planet beneath Venus.
In a few evenings the planet dims considerably and plunges into bright sunlight. It passes between Earth and Sun and moves into the morning sky during late June.
Note that the star Elnath is 5.4° to the upper right of Venus. The star is the northern horn of Taurus and means “the one butting with horns.”
Mars is higher in the sky, marching eastward in Gemini. Use the binocular to spot the starfield. The planet is 5.4° to the lower left of Pollux and 2.3° below Kappa Geminorum (κ Gem).
Articles and Summaries
- Venus as an Evening Star
- Venus Evening Star (Summary)
- Mercury during May 2021
- Mars during 2021 (Summary)
- Mars during May 2021
- Planets during May 2021
Detailed Note: One hour before sunrise, the bright gibbous moon (17.6d, 88%) is over 20° up in the south. It is above the handle of the Teapot of Sagittarius, 3.6° to the upper left of Tau Sagittarii (τ Sgr, m = 3.3). Farther eastward, Saturn is nearly one-third of the way up in the south-southeast. Saturn is retrograding in Capricornus, 0.6° to the lower right of θ Cap. It is moving westward compared to that stellar signpost. For the past few mornings, the gap between them is the same when rounded to a tenth of a degree. Jupiter, at nearly the same altitude as Saturn, is 17.9° to the left of Saturn. In the starfield, the Jovian Giant is 2.6° to the upper left of ι Aqr, 4.1° to the lower right of θ Aqr, and 4.3° to the upper right of σ Aqr. Three planets are visible after sunset, although dimming Mercury is rapidly leaving the evening sky. Thirty minutes after sunset, brilliant Venus is over 8° above the west-northwest horizon. Mercury (m = 2.5) is 1.2° below Venus. At this time interval, use a binocular to see Mercury with Venus. Forty-five minutes after sunset, Venus is about 6° above the horizon. Mercury is lower in the sky and a challenge to locate. Venus is 5.4° to the lower left of Elnath. Mars is higher in the sky, over 25° above the west horizon, in Gemini. Fifteen minutes later, Venus is over 3° up in the sky. In the starfield, Mars is 3.8° to the upper left of δ Gem, 2.3° below κ Gem, and 5.4° to the lower left of Pollux.
Newly released analysis from the Mars Reconnaissance Orbiter shows that the Arabia Terra region on Mars experienced powerful volcanic eruptions.
September 30, 2021: An hour before sunrise, the crescent moon is near the Gemini Twins.
September 29, 2021: The thick crescent moon is in the southeast before sunrise, approaching the middle of Gemini. The evening planet pack is visible after sunset.
September 28, 2021: This morning the moon, as it approaches its Last Quarter phase, is high in the south at the Gemini – Taurus border. The evening planet pack – Venus, Jupiter, and Saturn – brightly shine after sunset.
September 27, 2021: Before sunrise this morning, the bright moon seems caught between the horns of Taurus, Elnath and Zeta Tauri. The planet pack, Venus, Jupiter, and Saturn, are visible after sundown.