2021, February 23: Mercury-Saturn Conjunction, Almost!

February 23, 2021. A quasi-conjunction of Mercury and Saturn.
2021, February 23: During bright morning twilight, Mercury appears to the left of Saturn. Jupiter is very low in the sky.

2021, February 23:  Mercury-Saturn Conjunction, Almost!

February 23, 2021: Jupiter and Saturn are returning to the morning sky.  Before sunrise, Mercury is near Saturn in a quasi-conjunction, a near conjunction.  Mercury does not pass Saturn. During the evening, Mars is closing in on the Pleiades star cluster while the bright moon is near Pollux.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:34 a.m. CST; Sunset, 5:34 p.m. CST.  Check local sources for sunrise and sunset times for your location.

Morning Sky

With the recent public focus on the great conjunction of Jupiter and Saturn, a near conjunction (quasi-conjunction) of two planets might be considered to be a let-down.

During the second half of February, Jupiter and Saturn are emerging from their conjunction with the sun that occurred about month ago.

They are visible low in the east-southeast, about 30 minutes before sunrise.  You’ll need a binocular and a clear natural horizon to see them.

As they leave the bright sunlight into morning twilight, Mercury is appearing in the morning sky for a brief appearance, but Mercury does not reach Saturn.

While they appear at about the same altitude above the horizon this morning, Mercury does not pass Saturn in the coordinate system.

A conjunction would occur if Mercury and Saturn had the same celestial longitude on the sky’s imaginary coordinate system. 

When one planet approaches another planet to a minimum distance of 5.0° or less, this is defined to be a quasi-conjunction.

The last quasi-conjunction occurred during when Jupiter approached Saturn during May 2020 before Jupiter began its retrograde motion.

The next quasi-conjunction is with Mercury and Saturn after sunset in the southwest on January 12, 2022.

This morning, look for Mercury 4.0° to the left of Saturn.

Evening Sky

February 23, 2021. Mars approaches the Pleiades star cluster.
2021, February 23: During the early evening hours, Mars is high in the southwest, below the Pleiades star cluster.

This evening Mars appears in the constellation Taurus.  The planet is nearly 6° to the lower right of the Pleiades star cluster.  Look about two-thirds of the way up in the southwestern sky.  Six or seven stars of the cluster are easily visible to the unaided eye.  Through a binocular a few dozen stars are visible.

Children likely know the cluster as the “Seven Sisters.”  It looks like a tiny dipper, although do not confuse it for the Little Dipper.

During early March, Mars passes the cluster.  Use a binocular to watch Mars approach and pass the star cluster.

Here’s more about Mars during 2021.

Read about Mars during February.

February 23, 2021: The gibbous moon is near Pollux.
2021, February 23: After sunset the gibbous moon is high in the east near Pollux.

Farther east, the bright moon is to the lower right of the bright star Pollux.  From the American Southeast, Mexico, Central America, parts of South America, the moon blocks the star Kappa Geminorum.  If you live in the region, see the details at the web site linked in the detailed notes below.

Detailed Note: Thirty minutes before sunrise, find a clear horizon and use a binocular to find Saturn, nearly 6° up in the east-southeast. Mercury (m = 0.5) is 4.0° to the left of Saturn.  This is the closest Mercury approaches Saturn during this Mercurian appearance – a quasi-conjunction. Another Mercury – Saturn quasi-conjunction occurs after sunset on January 12, 2022, when Mercury is nearly 3.4° to the lower right of the Ringed Wonder. One hour after sunset, the moon (12.2d, 87%) is 60° up in the east-southeast. The lunar orb is 3.9° to the lower right of Pollux (m = 1.2) and 0.2° to the lower right of Kappa Geminorum (κ Gem, m = 3.6). The star is occulted from the southeastern U.S., Mexico, Central America, and parts of South America.  (For more information see http://www.lunar-occultations.com/iota/bstar/0224zc1170.htm.) Farther west, Mars moves into Taurus, 5.6° to the lower right of Alcyone.  The planet is over two-thirds of the way up in the sky above the southwest horizon.

Read more about the planets during February.



Categories: Astronomy, Sky Watching

Tags: , , , , , , , ,

Leave a Reply

%d bloggers like this: