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

Of the naked-eye planets, fast-moving Mercury is always the most challenging to observe, because it's usually lost in the Sun's glow. Our best opportunities to catch it occur at eastern or western elongation, when its angular separation from the Sun is greatest and it's far enough away from the glare so it can be seen shortly before dawn or soon after sunset. As July opens, Mercury is about a week past greatest eastern elongation and is located in the evening sky, setting about an hour after the Sun, but the low angle of the ecliptic (the plane of the solar system) causes it to appear very close to the horizon, making it difficult to see in the glare, even near elongation. Eventually disappearing into the glow by mid-month, it reaches inferior conjunction on July 21, when it passes between Earth and the Sun. Emerging into the morning sky in early August, it reaches greatest western elongation on August 9 when it rises about an hour and a half before dawn. It's visible before sunrise until late August, when it retreats back into the Sun's glow and disappears behind our star, reaching superior conjunction on September 3.

The thin, waxing crescent Moon passes near Mercury on July 3 and ordinarily might help observers to find the elusive planet less than an hour after sunset, but both will be difficult to see in the twilight. The next encounter between the two on August 29 will be lost in the Sun's glare, and the following meeting isn't all that much easier to see just after sunset on September 29, when Mercury sets only 40 minutes after the Sun.



The planet venus, image by NASA/Caltech/JPL

With superior conjunction on August 13, this season is not a good time to look for Venus in the Sun's glow. At the beginning of July, Venus is a morning object, rising less than an hour before the Sun and already retreating into the glare, so each morning offers slightly less time to see it before it's washed from view by mid-month. This is our only chance to see Venus this quarter, as it then passes behind the Sun and slowly moves into the evening sky, not returning to our view until October..

The day-old waxing crescent Moon is near Venus on July 3 and theoretically visible very low in the west-northwest after sunset, but that's only with perfect conditions and will be a difficult challenge. Close encounters between the two for the next few months—on July 31, August 30, and September 28 —are completely washed from view.



The planet Mars, image by NASA

Gradually moving into the Sun's glow, Mars is barely visible in the early evening sky, located very low in the west-northwest soon after sunset at the beginning of July, and as with Venus, it doesn't get any better for the rest of the season. As it moves deeper into the Sun's glow, it's washed from view and reaches conjunction on September 2, when it's behind the Sun relative to Earth. The Red Planet isn't seen again until mid-October, when it rises before dawn.

As is the case with Venus, the Moon's passes nearby on July 3, August 1, August 30, and September 27 are too close to the Sun to be seen.



The planet Jupiter, by NASA

At the beginning of July, the largest planet is already visible in the south-southeast an hour after sunset, not far from the bright, reddish star Antares (the heart of Scorpius the Scorpion). As one of the more distant naked-eye planets, it moves very slowly and barely changes its location against specific stars through September. It does, however, follow the slow, westward drift of the sky during the season, so by the beginning of August, look for it due south an hour after sunset, and as September commences, Jupiter is in the south-southwest in the early evening.

The waxing gibbous Moon passes near Jupiter on the night of July 13 (close enough for both to be visible in the same field of view in most binoculars), even closer on August 9 and September 5, the latter date when the Moon is at its last quarter phase. Mount the binoculars on a steady tripod, and Jupiter's largest moons should also be visible!



The planet Saturn, by NASA/JPL/Saturn institute

This is the best time to observe Saturn, which is at opposition on July 9 and rises at sunset. By nightfall, the Ringed Planet is low in the southeast and visible all night as it slowly crosses to the southwest. At the beginning of August, Saturn is low in the southeast an hour after sunset, and at the beginning of September, it's in the south-southeast at nightfall, the whole time located against the stars of Sagittarius the Archer, where it'll remain until next spring.

The Moon sweeps past Saturn on the nights of July 15, August 11, and September 7 & 8.


Sunrise & Sunset Table

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

July 1
Sunrise | Solar Noon | Sunset
5:52 am | 1:13 pm | 8:36 pm 
All times PDT

August 1
Sunrise | Solar Noon | Sunset
6:13 am | 1:16 pm | 8:18 pm
All times PDT

September 1
Sunrise | Solar Noon | Sunset
6:40 am | 1:09 pm | 7:39 pm
All times PDT