National Astronomical Observatory of Japan



The Moon Passing Close to Saturn (June, 2017)

June 9, 2017, 22:00, the sky of Tokyo
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A Great Chance to Observe Saturn

In early June, Saturn rises in the southeastern sky a little after sunset. On the 9th and 10th, you can see the Moon near Saturn. The Moon around the full moon is very bright, so even 0 magnitude Saturn will look like a discreet glow.
Saturn passes opposition on June 15 and this will be a good time for you to look at it.

Saturn’s photo on June 2, 2016
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The most famous feature of Saturn is its beautiful rings. The rings are made up of ice grains whose sizes range from a few centimeters to a few meters in diameter. Among the rings, you can see the wide and bright A Ring and B Ring, and the gap between the A Ring and B Ring with a small telescope. This gap is called the "Cassini Division." Many rings other than the A Ring and the B Ring have been found around Saturn.

Change in apparent inclination of Saturn’s ring system
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The ring of Saturn is tilted about 27 degrees with respect to Saturn’s orbital plane. The orientation of that tilt doesn’t change during the roughly 30 years it takes Saturn to orbit the Sun. Therefore, the inclination of Saturn's ring, as seen from the Earth, increases and decreases at intervals of about 15 years, which is half the orbital period. This year is the period when Saturn’s ring appears to incline the most, as shown on the far right of the figure above. When you view Saturn with a telescope, it seems as though the greatly inclined ring surrounds Saturn's body completely.

Reference: Ephemeris Computation Office

You can look up the rising and setting times for the Sun and the Moon, and the phases of the Moon in the “Koyomi Station” of the NAOJ Ephemeris Computation Office. You can find the appearance of the Moon and planets as seen from a typical city under “Sky Viewer.”