The chart above displays the setting time of Venus (green curve) compared to sunset. The three phases of twilight are displayed as well. The setting time differences are displayed for bright stars near the ecliptic as well as other bright planets. The moonset interval is displayed with circles. The rising time difference – compared to sunset – is displayed for Jupiter and Saturn as well. When the planets rise at sunset, they are at opposition.
Venus as an Evening Star, semi-technical summary.
Saturn’s opposition with Venus is displayed as a brown box on the Saturn Rising line. A yellow box on the Jupiter Rising line indicates a similar event, Venus – Jupiter opposition. In the evening, when two planets are at opposition, opposite sides of Earth, one is rising as the other sets. A week or so after these dates Saturn, then Jupiter, appear in the eastern sky as Venus shines from the west. In this study of Venus, this trio is in the sky together during evening hours until nearly the end of its evening appearance during early 2022.
When the Venus curve crosses another line, Venus and that celestial object set at the same time. Conjunctions occur near this date. White boxes on the charts indicate conjunctions with stars and other planets. The yellow triangle, with the letters “GE,” indicates the greatest elongation dates of Venus and Mercury.
The setting chart is from data by the U.S. Naval Observatory’s Multiyear Interactive Computer Almanac (MICA) for Chicago, Illinois. Make any appropriate adjustments for different latitudes. Time intervals after sunset are used in the following notes for observers to determine the appropriate observing clock time at their locations.
July 6, 2021: In less than a week, brilliant Venus passes Mars in the west-northwestern sky after sunset. This evening the two planets are 3.8° apart. Venus is over 18° to the lower right of the star Regulus.
July 1 – July 7, 2021, the waning crescent appears in the eastern sky. Early in the viewing period, the moon is among the dim stars of Pisces. As the week progresses, the moon wanes and moves farther eastward, appearing near Taurus.
July 5, 2021: Our planet Earth reaches its farthest point in its yearly trek around the sun. Our seasons are not related to Earth’s distance from the sun. Coincidentally, the moon is at its farthest point from Earth today.
July 5, 2021: Venus continues to close in on Mars in the west-northwest after sunset. In a week Venus passes the Red Planet.
July 4, 2021: The Venus – Mars conjunction is eight days away. This evening Venus moves to within 5° of the Red Planet.