2021, August 11: Waxing Moon, Evening Star

August 11, 2021:  The waxing crescent moon is to the upper left of Evening Star Venus this evening in the western sky.

2021, August 11: The crescent moon is 8.1° to the upper left of Venus.
Chart Caption – 2021, August 11: The crescent moon is 8.1° to the upper left of Venus.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:55 a.m. CDT; Sunset, 7:56 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

This evening a magnificent display occurs with the crescent moon and Evening Star Venus.  The moon began its new cycle of lunar phases over 3 days ago.  It is 14% illuminated.

Step outside about 45 minutes after sunset and look westward.  The crescent moon is about 14° up in the west.  That’s about the height the sun is about an hour before sunset.  It’s low, so find a spot away from trees, houses, and other terrestrial obstructions.

Venus is lower in the western sky, 8.1° to the lower right of the lunar slice.  It continues to climb into the evening sky, since its first appearance during late April.  The planet is racing eastward each night as it begins to approach the star Spica, although its nightly elevation above the horizon stays the same for about the next month.  Notice though that Venus is appearing a little farther southward along the horizon each evening.

2020, July 17: The crescent moon appears near Venus before sunrise. The night portion of the moon is gently illuminated by earthshine.
Photo Caption – 2020, July 17: The crescent moon appears near Venus before sunrise. The night portion of the moon is gently illuminated by earthshine.

The night portion of the moon displays earthshine, reflected sunlight from Earth’s oceans, clouds, and land gently illuminate the night portion of the moon.  The view through a binocular brings out the view of the crescent and the gentle illumination of the lunar night.

The moon, January 15, 2021
2021, January 15: The thin waxing moon with earthshine, reflected sunlight from Earth’s features gently illuminates the lunar night.

Earthshine can be photographed with a tripod mounted camera with an exposure of a few seconds. 

Note that the Perseid meteor shower peaks after midnight and before the beginning of morning twilight tomorrow.

Detailed Daily Note: One hour before sunrise, Jupiter is about 19° above the southwest horizon. According to Jean Meeus’ equations, this morning is the first morning appearance (the heliacal rising) of Sirius.  Look for it low in the east-southeast about 40 minutes before sunrise. The sun is in the sky for 14 hours today.  Forty-five minutes after sunset, the moon (3.5d, 14%) is about 14° up in the west, 8.1° to the upper left of Venus that is about 8° above the western horizon.  Use a binocular to spot Zavijava (β Vir, m = 3.6), 2.3° to the upper left of Venus.  Venus is quickly moving eastward along the ecliptic.  This evening the gap to Spica, 16° up in the west-southwest, is 29.1°.  At this hour, Saturn is nearly 12° up in the southeast.  Jupiter is near the east-southeast horizon, but bright enough to be seen if the view is clear.  As midnight approaches, Jupiter and Saturn are nearly 30° up in the sky.  Saturn is above the southern horizon, while Jupiter is in the south-southeast.  Saturn continues to retrograde in Capricornus.  It is 4.7° to the lower right of θ Cap and 1.8° to the lower left of Upsilon Caprcorni (υ Cap, m = 5.1).  Use a binocular to spot the dim star near the Ringed Wonder.  The Perseid meteor shower peaks overnight.

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