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

Planet Watch is our guide to planetary activity for April through June 2017.

The planet Mercury, image by NASA/JPL

The smallest planet might be briefly visible, soon after sunset at the beginning of April, but it quickly overtakes the Sun and passes inferior conjunction on April 19, passing into the morning sky. However, the angle of its path against the stars is so shallow with respect to the horizon that it doesn't get very high above the horizon, even at greatest western elongation (greatest angular separation from the rising Sun) on May 17. With the quickest orbit around the Sun (88 days), it is at superior conjunction on June 21, passing behind the Sun and returning to the early evening sky. The Moon's passes near Mercury on the morning of April 25 and May 24 are too close to the Sun to be seen, as is the close-encounter on the evening of June 24.

The planet venus, image by NASA/Caltech/JPL

A morning object, Venus is at greatest brilliancy on April 29, then reaches greatest western elongation June 3, rising about two hours before sunrise. At this time, take careful note of how long you can continue to see it with the unaided eye, even as the Sun rises. Venus remains in the predawn sky for the rest of the season, with the waning crescent Moon appearing nearby on the mornings of April 23, May 22, and June 20.

The planet Mars, image by NASA

Starting the season very low in the west just after sunset, the Red Planet gradually sinks further into the glow of the setting Sun, disappearing from view by late-May. The waxing crescent Moon swings nearby on the evening of April 27 and May 26 (although the latter may be too difficult to see in the Sun's glare), and its encounter on June 24 is too close to the Sun to be observed.

The planet Jupiter, by NASA

This season, the largest of the planets becomes easier to see, reaching opposition on April 7 when it rises at sunset and is prominent in the early evening sky, visible all night. The Moon can be seen near Jupiter on the nights of April 10, May 7, and June 3.

The planet Saturn, by NASA/JPL/Saturn institute

The Ringed Planet–the second-largest in the solar system–rises at about 1:30 am at the beginning of April, at 11:30 at the beginning of May, and at 9:30 at the beginning of June. In late-May, the slowest-moving of the naked-eye worlds gradually crosses the border between constellations from the stars of Sagittarius the Archer into those of Ophiuchus the Snake-Bearer. The Moon passes nearby on the morning of April 16, when both rise shortly after midnight, and on the night of May 13, rising together just before midnight. On the night of June 9, the bright full Moon and Saturn rise shortly after sunset. Saturn is most easily-observed near opposition on June 15, when it rises at sunset and is conveniently visible all night.

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Planetarium by Night

Planetarium by Night

Morrison Planetarium is open for Thursday NightLife events, featuring special shows and presentations. 

2017 Pocket Almanac

2017 Pocket Almanac

Download the Morrison Planetarium's 2017 Pocket Almanac to stay up-to-date on eclipses, meteor showers, satellite spottings, and more.

2017 Morrison Planetarium pocket almanac