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

Each quarter (which lasts 90-92 days), Mercury nearly completes a cycle of phases (or synodic period), which lasts 116 days. At the beginning of April, the little planet is hidden behind our star, reaching superior conjunction on the 2nd. Gradually moving eastward, it makes a favorable appearance in the early evening sky by mid-month and reaches its greatest eastern elongation on April 29th, when it sets a little less than two hours after the Sun. By early May, it retreats into the Sun's glow, passing between Earth and the Sun and reaching inferior conjunction on May 21. It briefly pops back into view in the predawn sky and reaches greatest western elongation on June 16. That's the time to look for it as it joins a grand procession of all six naked-eye solar system objects, stretched across the southeast just before dawn. See Highlights for more on the Planetary Parade.

The waning crescent Moon has four meetings with Mercury this season, only one of which is easy to see. The first on April 1 occurs very near superior conjunction, when both are too close to the Sun to be seen. Their encounter on May 2 is a little farther from the Sun and near enough to its greatest eastern elongation that it might be visible very low in the west-northwest just after sunset. Their meeting on May 29 is again too close to the Sun to be seen, but on June 27 they both take part in that magnificent morning parade of solar system objects mentioned just above.



The planet venus, image by NASA/Caltech/JPL

The brightest of the planets is a morning object for the entire season, visible low in the east-southeast an hour before dawn in early April between the stars of Capricornus the Sea-Goat and Aquarius the Water-Carrier, easily outshining closely paired Saturn and Mars to its right. Through the season, it maintains a fairly consistent height above the horizon when seen at the same time before dawn, following the Sun northward. By mid-May, it is seen due east an hour before dawn against the stars of Pisces the Fishes. By the end of the season, it rises in the east-northeast against Taurus the Bull. As detailed in Highlights, it joins the other planets in a predawn procession, passing very close to Jupiter on April 30, when the two are separated by less than the apparent diameter of a full Moon.

Speaking of the Moon, our satellite makes an apparent close pass near Venus on the mornings of April 27, May 27, and June 26, each time a thin sliver of a waning crescent.



The planet Mars, image by NASA

The Red Planet is a predawn object this season, making a very close (half-a-degree) approach to Saturn on the morning of April 4 and then almost as close a pass near Jupiter on May 29. This season, it slowly creeps from the stars of Capricornus the Sea-Goat through Aquarius the Water-Carrier and into Pisces the Fishes, taking part in the beautiful cavalcade of planets that is detailed in Highlights.

The waning crescent Moon passes close to Mars on the mornings of April 25-26, May 24-25 (with bright Jupiter very close to Mars as well), and June 22.



The planet Jupiter, by NASA

The largest planet in the Solar System can be seen before dawn this season, rising in the southeast close to an hour before dawn in early April against the stars of Aquarius the Water-Carrier. In mid-April, it plods into Pisces the Fishes and joins a fairly evenly spaced line that includes Venus, Mars, and Saturn, with the waning crescent Moon joining in by the end of the month. On the morning of April 27, Jupiter gathers tightly with the Moon and Venus, and on the morning of April 30, Venus and Jupiter have a very close encounter, separated by less than a half-degree (or less than the apparent width of the Moon). A month later, on May 29, as mentioned above, reddish Mars makes almost as close an approach to the giant planet.

The Moon passes near Jupiter on the mornings of April 27 (with Venus nearby), May 24-25 (with Mars nearby), and June 21.



The planet Saturn, by NASA/JPL/Saturn institute

At the beginning of April, the Ringed Planet rises less than two hours before dawn clustered with Venus and Mars (less than a degree from Mars on the mornings of April 4-5). The slowest-moving of the naked-eye planets, it dawdles against the stars of Capricornus the Sea-Goat all season, gradually climbing higher into the predawn sky as the other planets separate eastward from it. By June 1, it's located high in the south-southeast just before dawn.

The Moon joins Saturn on the morning of April 24, May 22, and June 18—but don't miss the other planets strung out in a line to the east of Saturn.


Sunrise & sunset table

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

April 1 (PDT)
Sunrise | Solar Noon | Sunset
6:54 am | 1:13 pm | 7:33 pm 

May 1 (PDT)
Sunrise | Solar Noon | Sunset
6:13 am | 1:06 pm | 8 pm

June 1 (PDT) 
Sunrise | Solar Noon | Sunset
5:49 am | 1:07 pm | 8:26 pm