2021, November 27:  Venus at Greatest Brightness


November 27, 2021: Beginning this evening and lasting until December 14, Venus is at its greatest brightness.

Chart Caption – 2021, November 27: Venus, Saturn, and Jupiter are in the southern sky after sunset.


Chicago, Illinois:  Sunrise, 6:55 a.m. CST; Sunset, 4:22 p.m. CST.  Check local sources for sunrise and sunset times for your location.

Step outside after sunset during the next few evenings.  Look to the southwest.  Venus is intensely bright.  Saturn is about 20° to the upper left of Venus and Jupiter is over 16° to the upper left of the Ringed Wonder.  Venus seems to be closing in on Saturn, but a conjunction of Venus and Saturn does not occur until after both planets pass their conjunctions next year.

This evening the planet starts its interval of greatest brightness.  The interval lasts through December 14.  With scientific instruments that measure the brightness of celestial objects, Venus will grow slightly in brightness until December 4, but the human eye is not likely to detect that tiny brightness increase.

Venus is approaching Earth and its highly reflective clouds are putting on a show in our skies.  This evening the planet is 45 million miles away from Earth.  Through a telescope the planet shows an evening crescent phase that is 31% illuminated.

On December 4, Venus is at its “greatest illuminated extent.”  That’s quite an interesting statement.  On this evening the planet is slightly over 37 million miles from our world.  Its evening crescent phase is 26% illuminated.

This crescent phase covers the largest portion of the sky.  While the phases are visible only with optical assistance, this phase covers the largest area of the sky.  We might think that a gibbous phase of Venus covers the largest section because it is nearly a full circle of light.  This phase occurs when the planet is farthest from Earth and it appears small in the sky.

Since early May, the planet’s apparent diameter in the sky through a telescope has increased over four times.  The phase has changed from gibbous to half full and now to crescent.  That thinning crescent covers more area than the gibbous phase from six months ago. The result is that Venus is at its brightest in the sky. 

For those readers who want more information about the greatest illuminated extent, here is a semi-technical article.

As Venus is extremely bright in the southwest after sunset, the crescent moon passes by on December 6.  This is the final grouping of Venus and the evening crescent moon for this evening appearance of Venus.  It is likely the most photogenic grouping of the Venusian apparition with the intensely brilliant planet and the crescent moon 10% illuminated.  This is a do not miss event. Meanwhile, Venus is moving toward its inferior conjunction – between Earth and Sun – early next year.  Then the planet skips into the morning sky in the southeast.



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