2021, May 12: Morning Planets Jupiter, Saturn

May 12, 2021: Before sunrise bright Jupiter, in front of Aquarius, is in the southeast before sunrise.  Saturn is to the upper right of Jupiter, in Capricornus.  In a few mornings, Saturn begins to retrograde.

2021, May 12: Morning planets Jupiter and Saturn are in the southeastern sky before sunrise.
Chart Caption: 2021, May 12: Morning planets Jupiter and Saturn are in the southeastern sky before sunrise.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:33 a.m. CDT; Sunset, 8:01 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

The morning planet parade starts with bright Jupiter and Saturn low in the southeastern sky before sunrise.

Jupiter is brighter than all the stars in the morning sky.  It is 21.0° up in the southeast.  It is slowly trekking eastward in front of the stars of Aquarius.

Use a binocular to spot the star Iota Aquarii (ι Aqr on the chart), 1.5° to the lower right of the planet.  Make observations each clear morning to note the orientation of Jupiter compared to the star as well as its distance from the stellar signpost.

Saturn – brighter than most of the stars this morning, but dimmer than Jupiter – is over 16° to the upper right of the Jovian Giant.

The Ringed Wonder is 0.7° to the right of Theta Capricorni (θ Cap).

In three mornings, Saturn seems to stop moving eastward compared to the star.  During the next few days, it does not appear to move much compared to that seemingly fixed point in space.

As Saturn revolves around the sun, it does not stop in its orbital path.  Rather, this is an illusion from our faster moving planet overtaking Saturn.  Compared to the background stars, Saturn seems to stop moving eastward and appears to move backwards or westward.

Watch Saturn with a binocular compared to Theta Capricorni.  The gap between them opens slowly at first.  Then it widens noticeably each day.

The sun’s appearance interrupts the planet parade.  Venus, Moon, Mercury, and Mars are visible after sunset.

Detailed Note: One hour before sunrise, bright Jupiter is 21.0° up in the southeast.  It is 1.5° to the upper left of ι Aqr.  Saturn – over 24° up in the south-southeast – is 16.4° to the upper right of Jupiter. Saturn is 0.7° to the right of θ Cap.  Three planets are on display after sunset.  Thirty minutes after sundown, brilliant Venus is over 5° up in the west-northwest.  Use a binocular to locate the razor thin moon (1.3d, 1%) 1.2° to the left of Venus.  This is the closest pairing of Venus and the moon during this evening apparition of the planet.  Fifteen minutes later, the Venus – moon pair is still about 3° above the horizon.  Mercury (m = −0.1) is 9.1° to the upper left of Venus.  One hour after sunset, Mercury is nearly 9° above the west-northwest horizon with Mars over 28° to its upper left.  In the starfield Mars is 1.8° to the upper left of ε Gem and 4.8° to the right of ζ Gem.

Read more about the planets during May 2021.



Categories: Astronomy, Sky Watching

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