2025, July 27-31: Evening Moon, Mars, Virgo

July 27-31, 2025: The waxing moon passes Mars and Spica in late July. Mars approaches Zavijava for a close conjunction on August 2nd. Look for earthshine on the 27th and 28th.

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by Jeffrey L. Hunt

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Evening Waxing Moon

Mars, Moon, Spica, July 27-31, 2025
Chart Caption – 2025, July 27-31: The moon waxes eastward passing Mars, Zavijava, Porrima, and Spica.

The waxing moon, on lunation 1269 – the number of lunar cycles since the count began over a century ago – makes a low arc across the west and southwest sky.  The plane of the solar system makes a shallow angle with the western sky during the evening hours at this season.

When approaching the First Quarter phase, the moon is barely above 20° altitude after it passes Spica.  This is a contributing factor to the challenging views of Mars. A second factor is the planet is far from Earth and considerably dimmer that when it was relatively nearby earlier in the year.

Mars marches eastward, crossing the Leo/Virgo border on the 28th.  It is approaching Zavijava, also known as Beta Virginis.  Their conjunction occurs on August 2nd, when Mars passes 0.1°, about one-fourth of the moon’s diameter, to the star’s lower left.

2021, December 6: The moon with earthshine.
Photo Caption – 2021, December 6: The moon with earthshine.

Look for earthshine on the moon’s night portion on the 27th and 28th.  This effect is from sunlight reflecting from a nearly full earth, as viewed from the moon.  That light softly lights up the lunar night.  When the moon is nearly 30%-lit, as beginning on the 29th, the moonlight is bright enough to illuminate terrestrial features and cast shadows.

Photograph earthshine with a tripod-mounted camera and exposures up to a few seconds.  A steady handheld smartphone camera can capture the scene.

Waxing Moon Highlights

At one hour after sunset, here’s what to see:

  • July 27: The crescent moon, 12% illuminated, is less than 10° up in the west, less than 9° to Mars’ lower right. Mars is 3.6° to Zavijava’s lower right.  About 20° above the southwest horizon. Spica is over 30° to the moon’s upper left.
Binocular View - Mars, Moon, Zavijava, July 28, 2025
Chart Caption – 2025, July 28: Mars, crescent Moon, and Zavijava fit into a single binocular field of view.
  • July 28: At 19% illumination, the crescent moon is over 10° up in the west-southwest and 4.0° to Mars’ lower left. The Red planet is 3.0° to Zavijava’s lower right.  Mars, Moon, and star fit into a circle 4.3° across and easily into the same binocular field of view.  Look for earthshine on the moon. Spica is over 25° to the moon’s upper left.
  • July 29: The moon, 27% illuminated, is nearly 15° above the west-southwest horizon, 15° to Mars’ upper left and 14° to Spica’s lower right.  Look for Porrima, also known as Gamma Virginis, 5.5° to the moon’s upper right. Mars is 2.4° to the lower right of Zavijava.
  • July 30: The moon, 27% illuminated, is less than 20° above the southwest horizon, 2.6° to Spica’s lower right. Mars is 1.8° to Zavijava’s lower right.
  • July 31: Nearing the First Quarter phase, the moon, 45% illuminated, is about 20° above the southwest horizon, 10° to Spica’s lower left.  The Mars-Zavijava gap is 1.2°.

The waxing moon makes a low arc across the western sky during the final evenings of July. Mars, dimmer now and farther from Earth, marches eastward in front of Virgo toward a close conjunction with Zavijava on August 2nd. Each evening, the moon moves past Mars and Spica, offering excellent opportunities for observing and photographing the changing sky. Look for earthshine on the moon’s night portion on July 27th and 28th. Use a binocular to follow Mars as it closes in on Zavijava, passing only 0.1° to the star’s lower left. The moon’s brightness increases each night, casting shadows beginning July 29th.

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