2021, March 5: Moon, Antares, 3 Morning Planets

March 5, 2021: About an hour before sunrise, find the slightly gibbous moon to the upper right of the star Antares in the southern sky.  The morning triple dip of planets – Jupiter, Mercury, and Saturn – is low in the east-southeast before sunrise.  Mercury passes Jupiter this morning.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:19 a.m. CST; Sunset, 5:46 p.m. CST.  Check local sources for sunrise and sunset times for your location.

This morning, the slightly gibbous moon is in the southern sky during morning twilight. (The moon reaches its Last Quarter phase at 7:30 p.m. CST this evening.)  The moon is 5.0° to the upper right of Antares (“the rival of Mars”), the brightest star in Scorpius.  Note that the lunar orb is 4.2° to the lower left of Graffias (“the crab”).  Use a binocular to see the starfield behind the moon.

Three planets are visible during bright twilight.  The brightest is Jupiter.  Thirty minutes before sunrise use a binocular to find it about 5° in altitude in the east-southeast.  Mercury passes the Jovian Giant this morning.  This speedy planet is 0.3° to the upper left of Jupiter. 

Saturn is 8.6° to the upper right of Jupiter, more than a binocular field away.  To find Saturn, put Jupiter at the lower left of the field, then move the binocular slightly to the upper right.  Saturn will appear in the view.

Detailed Note: One hour before sunrise, the moon (21.7d, 57%) is 26° up in the south, 5.0° to the upper right of Antares (α Sco, m = 1.0) and 4.2° to the lower left of Graffias (β Sco, m = 2.5).  Use a binocular to see the starfield behind the moon. Fifteen minutes later, Saturn is nearly 7° up in the east-southeast.  Jupiter is 8.6° of ecliptic longitude east of Saturn.  With a clear horizon, you might find Jupiter very low in the sky.  Thirty minutes before sunrise, use a binocular to locate Jupiter about 5° up in the east-southeast, with Mercury 0.3° to its upper left.  One hour after sunset, Mars is nearly 60° up in the west-southwest.  It is 2.8° to the left of Alcyone.  With a binocular spot 37 Tauri (37 Tau, m = 4.3), 2.6° to the upper left of Mars. The moon is at its Last Quarter phase at 7:30 p.m. CST.

Read more about the planets during March 2021.