May 5, 2021: Brilliant Venus, Mercury, and Mars are visible in the western sky after sunset. Venus is visible low in the west-northwest about 30 minutes after sunset. By 45 minutes after sundown, Mercury is visible to the brilliant planet’s upper left. Mars is easily visible and hour after the sun sets, about one-third of the way up in the west, in front of the stars of Gemini.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 5:42 a.m. CDT; Sunset, 7:54 p.m. CDT. Check local sources for sunrise and sunset times for your location.
Brilliant Venus, Mercury, and Mars, in the evening sky, join morning planets Jupiter and Saturn as five planets visible during a 24-hour period.
Begin looking for Venus about 30 minutes after sunset. It is about 4° above the west-northwest horizon. A binocular may be necessary to first locate it at a cloud-free horizon.
Bright Mercury, although it dims each evening, is 7.4° to the upper left of Venus. In this bright sky, use a binocular here as well.
Read more about Venus in our summary document.
By 45 minutes after sunset, Venus is near the horizon and Mercury is over 8° above the west-northwest horizon, easily visible to the unaided eye.
Use a binocular to see it to the upper left of the Pleiades star cluster. The speedy planet is 3.6° to the upper left of Alcyone (η Tau on the chart), the brightest star in the cluster.
By an hour after sunset, when the sky is darker, locate Mars about one-third of the way up in the western sky, below Castor and Pollux, the Gemini Twins.
Mars is marching eastward through the constellation. The ecliptic, the apparent plane of the solar system, cuts across the constellation in a diagonal line from the lower right corner of the chart to the upper left. Mars ends the month to the lower left of Pollux.
This evening, the Red Planet is 3.4° to the upper right of Tejat Posterior, “the heel,” (μ Gem on the chart) and 2.0° to the lower right of Mebsuta, “the outstretched paw of the lion,” (ε Gem).
At this hour, Mercury is about 6° above the west-northwest horizon, over 34° to the lower right of the Red Planet.
On May 16, Mercury reaches its greatest separation from the sun and begins its retreat toward bright sunlight and a close conjunction with Venus.
Mercury does not pass Mars during this appearance of the speedy planet. The pair has a close conjunction during the summer in bright evening twilight, setting up a challenging opportunity to see five planets in the sky simultaneously.
Here’s more about Mars during 2021.
Detailed Note: This morning the crescent moon (23.7d, 34%) is about 12° above the east-southeast horizon. It is 7.5° to the lower left of bright Jupiter. The lunar crescent is 5.2° to the upper right of Skat (“the leg,” δ Aqr, m = 3.2). Jupiter is 1.3° above ι Aqr. Saturn is 15.7° to the upper right of Jupiter in Capricornus. In the starfield, it is 0.8° to the right of θ Cap. Three bright planets are visible after sunset. Thirty minutes after sunset, brilliant Venus is nearly 4° above the west-northwest horizon. Mercury (m = −0.7) is 7.4° to the upper left of Venus. Fifteen minutes later, Mercury is over 8° above the west-northwest horizon and 3.6° to the upper left of η Tau. Use a binocular to spot 37 Tauri (37 Tau, m = 4.3) 0.9° to the lower left of Mercury. One hour after sunset, Mercury is about 6° above the horizon. Mars is over one-third of the way up in the west, 3.4° to the upper right of μ Gem and 2.0° to the lower right of ε Gem. Mars is 41.4° of ecliptic longitude east of Venus. Mercury is 34.3° of ecliptic longitude west of the Red Planet.
Read more about the planets during May 2021.
October 9, 2021: Look for brilliant Venus, crescent moon, and the head of Scorpius in the southwest after sunset. About every eight years, Venus and the moon appear near the head of the Scorpion after sunset. Look for them about 45 minutes after sunset.
October 1, 2021: Before sunrise, the lunar crescent is near the Beehive star cluster.
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.