2021, March 6: Morning Moon, Three Planets

March 6, 2021: During morning twilight, the thick crescent moon shines from the southern sky to the left of the star Antares.  Saturn is low in the east-southeast about 45 minutes before sunrise.  As the sky brightens further, Jupiter and Mercury are visible with the aid of a binocular.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:17 a.m. CST; Sunset, 5:47 p.m. CST.  Check local sources for sunrise and sunset times for your location.

This morning about an hour before sunrise, the thick crescent moon (45% illuminated) is less than one-third of the way up in the sky above the south-southeast horizon.  It is in front of the stars of Ophiuchus.

The lunar orb is nearly 12° to the left of Antares (“the rival of Mars”).  The star is the brightest star in Scorpius.  Sagittarius is farther east of the Scorpion.

This morning, Mercury is the farthest we see it from the sun (greatest elongation).  We only see the speedy planet during twilight.  At this season, Mercury suffers from our poor view of the inner solar system because that plane has a shallow angle with the horizon.

Mercury is near Jupiter about 30 minutes before sunrise, appearing low in the east-southeast.  With a binocular at this hour find bright Jupiter about 5° above the horizon. Mercury is 1.0° to the lower left of the Jovian Giant.  Both easily fit into the same binocular field of view.

Saturn is outside this field of view, nearly 9° to the upper right of Jupiter.  The Ringed Wonder is visible without optical aid about 45 minutes before sunrise, when it is nearly 7° in altitude.

Jupiter and Saturn are emerging from their solar conjunction during January.  After their close conjunction on the winter solstice, Jupiter is slowly stepping away from Saturn.

Mercury swings back into the sun’s glare and appears in the evening sky with Venus during late April and again during late May.

Detailed Note: One hour before sunrise, the moon (22.7d, 45%), over 22° up in the south-southeast in Ophiuchus, is nearly 12° to the left of Antares. Mercury reaches its morning greatest elongation (27.3°W) at 5:22 a.m. CST. Forty-five minutes before sunrise, Saturn is nearly 7° in altitude above the east-southeast horizon.  At this hour, Jupiter is only about 3° in altitude, nearly 9° to the lower left of Saturn.  Jupiter is visible at this altitude with an unobstructed, cloud-free horizon.  Fifteen minutes later, use a binocular to observe Jupiter, over 5° in altitude in the east-southeast, with Mercury 1.0° to its lower left. One hour after sunset, Mars, nearly two-thirds of the way up in the west-southwest, is 2.9° to the upper left of Alcyone and 2.0° to the lower right of 37 Tau.

Read more about the planets during March 2021.