2021, March 21: Three Bright Planets, Evening Moon

2021, March 21: Jupiter and Saturn are low in the southeastern sky at 45 minutes before sunrise.
2021, March 21: Jupiter and Saturn are low in the southeastern sky at 45 minutes before sunrise.

March 21, 2021: Jupiter and Saturn are visible in the southeastern sky before sunrise.  During the evening, the slightly gibbous moon is 25° to the upper left of Mars.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:52 a.m. CDT; Sunset, 7:04 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

Morning Sky

The giant-planet pair – Jupiter and Saturn – is low in the southeastern sky before sunrise.  Saturn is the highest, over 11° above the southeast horizon.  Jupiter – the brighter planet of the duo – is 10.6° to the lower left of Saturn and only 7.0° above the horizon.

Evening Sky

2021, March 21: The slightly gibbous moon is over 25° to the upper left of the Mars.
2021, March 21: The slightly gibbous moon is over 25° to the upper left of the Mars.

This evening the slightly gibbous moon is over 70° in altitude above the south-southwest horizon.  The moon’s terminator – the line that separates daylight from darkness – is slightly curved, indicating a gibbous phase.  The lunar orb is 54% illuminated this evening.

The reflected sunlight from the moon’s surface is bright enough to illuminate the ground and to cast shadows.  Step outside and let your eyes acclimate to the darkness.

The moon is front of the stars of Gemini, 2.6° to the upper left of Mu Geminorum (μ Gem on the chart).

Mars is farther west and lower in the sky in Taurus, over 25° to the lower right of the moon.  It is approaching the star Tau Tauri (τ Tau).  The separation is 2.0° this evening. Mars is easy to see without optical aid. Use a binocular to see the dimmer stars with the planet.

Here’s more about Mars during 2021.

Read about Mars during March.

Detailed Note: Forty-five minutes before sunrise, Saturn is over 11° in altitude above the southeast horizon.  Jupiter – 7.0° up in the east-southeast – is 10.6° to the lower left of Saturn. The moon is at its First Quarter phase at 9:40 a.m. CDT. One hour after sunset, the moon (8.6d, 54%) – in Gemini – is over 70° above the south-southwest horizon, 2.6° to the upper left of Mu Geminorum (μ Gem, m = 2.8).  Mars – over 50° above the west-southwestern horizon – is 2.0° to the lower right of τ Tau.

Read more about the planets during March 2021.



Categories: Astronomy, Sky Watching

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