March 4, 2021: Evening planet Mars passes the Pleiades star cluster and its brightest star Alcyone.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:20a.m. CST; Sunset, 5:45 p.m. CST. Check local sources for sunrise and sunset times for your location.
In the evening sky, Mars is the lone bright planet. It is moving eastward in front of the stars of Taurus and close to the Pleiades. While not as bright as it was at the beginning of the year, it is easy to spot with the bright winter stars.
Here’s where to find it: Step outside about an hour after sunset. (The planet and surrounding stars do not set until over 6 hours after sunset, so there’s a wide window to see it.) Look high in the west-southwest. A small group of dim, tightly packed stars will catch your eye. This is the Pleiades star cluster. Mars is to the lower left of the cluster.
Tonight, Mars passes the brightest star in the cluster, Alcyone. (Do not confuse Mars with Aldebaran, the reddish star to the upper left of the Pleiades) The separation is 2.6°. It’s not a close conjunction. Anytime a bright planet treks through the field is an interesting view.
Venus trekked through the region about a year ago.
The grouping is easily visible to the unaided eye. A binocular reveals many blue, and blue-white stars in the Pleiades star cluster.
Here’s more about Mars during 2021.
Read about Mars during March.
Detailed Note: One hour before sunrise, the moon (20.7d, 68%) is about 30° up in the south-southwest. It is between Gamma Librae (γ Lib, m = 3.9) and Iota Librae (ι Lib, m = 4.5). The lunar orb is 3.9° to the lower right of γ Lib and 3.5° to the upper left of ι Lib. Three planets are in the east-southeast before sunrise. Forty-five minutes before sunrise, Saturn is over 6° in altitude in the east-southeast. Fifteen minutes later, Jupiter is nearly 5° in altitude, over 8° to the lower left of Saturn. Use a binocular to find it with Mercury 0.6° to Jupiter’s upper right. One hour after sunset, Mars is less than 60° up in the west-southwest, 2.6° to the lower left of Alcyone, as the Red Planet passes the star this evening.
Read more about the planets during March 2021.
October 8, 2021: The crescent moon approaches Venus in the western sky this evening, leading up to tomorrow’s close grouping of Venus, the crescent moon, and the three stars of the Scorpion’s head.
October 7, 2021: The lunar crescent returns to the evening sky for a short visit in the western sky after sunset. The bright planet pack – Venus, Jupiter, and Saturn – are visible during the early evening.
Mars is at its solar conjunction on October 7, 2021. It begins a slow return into the morning sky. By year’s end it appears low in the southeastern sky with the moon.
October 6, 2021: The moon is at its New moon phase today. This evening look for the three bright planets after sunset.
October 5, 2021: Before sunrise, a very thin moon is visible in the eastern sky. The evening planet pack – Evening Star Venus, Jupiter, and Saturn – are visible at the same time after sundown.