Solar system showing relative size of (but not distance between) planets.

Keep tabs on our planets with Morrison Planetarium's quarterly guide to planetary activity.


The planet Mercury, image by NASA/JPL

Emerging from inferior conjunction and climbing out of the morning Sun's glow, the littlest planet makes a quick appearance in the predawn sky in mid-July, reaching greatest western elongation on the 22nd (see Highlights for a special opportunity happening that morning!).

Retreating back into the Sun's glow, Mercury is at superior conjunction on August 17, then reappears in the early evening sky in late August, but the shallow angle of the ecliptic (the plane of the solar system) at this time of the year keeps Mercury very low on the southwestern horizon, even when it reaches greatest eastern elongation on October 1. In other words, the planet's evening appearance in August and September will be unfavorable.

The Moon appears near Mercury on the mornings of July 18 and 19 and is the easiest of this season's encounters to observe, their pairings on August 18 and September 18 being too close to the Sun to be seen.



The planet venus, image by NASA/Caltech/JPL

The brightest planet in the sky is a "morning star" for the remainder of the year, rising before the Sun and gradually moving from the stars of Taurus the Bull through those of Gemini the Twins and Cancer the Crab, finally entering Leo the Lion at the end of September. Venus passes one degree from the bright star Aldebaran (the eye of Taurus) on July 12.

The waning crescent Moon makes a pretty pair with Venus, passing very near on the mornings of July 17, August 15, and September 14.



The planet Mars, image by NASA

The Red Planet rises just before 1 am on July 1, around 11:30 pm on August 1, and just before 10 pm on September 1. During the season, it lingers against the stars of Pisces the Fishes, crossing from the western side of that constellation almost to its eastern border, briefly tip-toeing through a corner of Cetus the Sea Monster during that time.

The Moon can be seen very close to Mars during the predawn hours of July 11 and 12, August 9, and September 5.



The planet Jupiter, by NASA

At opposition on July 13, the "king of the planets" is located opposite the Sun in the sky, rising at sunset and visible all night against the stars of the constellation Sagittarius the Archer. On July 1, it rises minutes after sunset, then rises a few minutes earlier on successive nights. By August 1, it rises about an hour before sunset, and roughly 2.5 hours before sunset by September 1.

The Moon passes by on July 5, Aug 1, August 28, and September 24, and since Jupiter and Saturn are so close together, these encounters involve all three objects, resulting in some very beautiful groupings.



The planet Saturn, by NASA/JPL/Saturn institute

Saturn's positional information is much like Jupiter's, since the two planets are less than seven degrees apart all season. Reaching opposition on July 20, Saturn rises around sunset within the boundaries of Sagittarius the Archer, following behind brighter Jupiter during the night. Both appear low in the southeast just after sunset in July, and are well above the horizon by nightfall in August and September.

The Moon swings near Saturn (and Jupiter) on the nights of July 5, August 1 and 2, August 28 and 29, and September 25.


Sunrise & Sunset Table

Times are for San Francisco, California (PDT) and will vary slightly for other locations.

July 1
Sunrise | Solar Noon | Sunset
5:51 am | 1:13 pm | 8:35 pm 

August 1
Sunrise | Solar Noon | Sunset
6:13 am | 1:15 pm | 8:17 pm

September 1
Sunrise | Solar Noon | Sunset
6:39 am | 1:09 pm | 7:38 pm


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