2021, May 19: Five Planets, Waxing Moon

May 19, 2021: The display of five planets continues.  Jupiter and Saturn are morning planets, visible in the southeast before sunrise.  After sunset, brilliant Evening Star Venus, Mercury, and Mars are in the western sky.  The half-full moon is to the upper left of Regulus.

2021, May 19: Bright morning planets, Jupiter and Saturn are in the southeast before sunrise. Jupiter is 17.0° to the lower left of Saturn.
Chart Caption – 2021, May 19: Bright morning planets, Jupiter and Saturn are in the southeast before sunrise. Jupiter is 17.0° to the lower left of Saturn.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:27 a.m. CDT; Sunset, 8:08 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

Five planets are visible in the sky today.  Jupiter and Saturn are in the southeastern sky before sunrise.  Venus, Mercury, Mars, and the moon are in the evening sky.

Morning Sky

Jupiter and Saturn are in the southeast before sunrise.  Saturn rises over 4 hours before sunrise. Jupiter follows less than fifty minutes later. By one hour before sunup, the Ringed Wonder is about one-third of the way up in the south-southeast.

Saturn is slowing its eastward trek compared to the stars of Capricornus. It begins to retrograde in a few mornings.  This morning the planet is 0.6° to the right of Theta Capricorni (θ Cap).

Bright Jupiter, 24° up in the southeast, is 17.0° to the lower left of Saturn.  The gap between the planets has opened since their great conjunction five months ago.

Jupiter is brighter than all the stars in the morning sky.  Saturn is dimmer than Jupiter, Vega, and Arcturus, but brighter than the other stars this morning.

The Jovian Giant continues its eastward ramble through Aquarius.  It is 2.0° to the upper left of Iota Aquarii (ι Aqr) and 4.6° to the lower right of Theta Aquarii (θ Aqr).

Use a binocular to see the dim starry background with the planets.  Both constellations are famous, but their stars are dim.

Five planets would be visible at once, but the sun’s brightness overwhelms the sky during the daytime.  Jupiter and Saturn set during the day. Venus, Mercury, and Mars rise during the daytime.  The moon is at its First Quarter phase at 2:13 p.m. CDT.  When you see the moon in the sky, the three planets are between the lunar orb and the sun.

Evening Sky

2021, May 19: Thirty minutes after sunset, brilliant Venus and Mercury are in west-northwest.
Chart Caption – 2021, May 19: Thirty minutes after sunset, brilliant Venus and Mercury are in west-northwest.

After sunset, brilliant Venus is entering the evening sky after its solar conjunction nearly two-months ago.  Thirty minutes after sunset, find it about 7° up in the west-northwest.  A clear, unobstructed horizon is needed to see the planet and a binocular may initially assist in finding the planet.

Mercury, dimming each evening, is 7.5° to the upper left of the brilliant planet.  This separation is the typical field of view of many binoculars.  Both may fit into the same field this evening.  If not then, locate Venus and move the binocular slightly to the upper left to view Mercury.

Venus as an evening star article.

Read more about Venus in our summary document.

2021, May 19: Forty-five minutes after sunset, Mars becomes visible with Venus and Mercury in the west-northwest.
Chart Caption – 2021, May 19: Forty-five minutes after sunset, Mars becomes visible with Venus and Mercury in the west-northwest.

By 45 minutes after sunset, a binocular may be needed to initially see Mercury.  At this hour, it is nearly 11° above the west-northwest horizon.  Depending on the view of the sky, Venus is still 4° above the horizon.

Mars, less than one-third of the way up in the sky in the west, is nearly 25° to the upper left of Mercury.

Here’s more about Mercury during May 2021.

2021, May 19: An hour after sunset, Mars is in the middle of Gemini, below Castor and Pollux, 3.4° to the upper right of Mekbuda (ζ Gem) and 3.5° to the lower right of Wasat (δ Gem).
Chart Caption – 2021, May 19: An hour after sunset, Mars is in the middle of Gemini, below Castor and Pollux, 3.4° to the upper right of Mekbuda (ζ Gem) and 3.5° to the lower right of Wasat (δ Gem).

By one hour after sunset, Venus is very low in the sky.  Look for the star Elnath, “the one butting with horns,” 3.8° to the upper right of Mercury. The star is the northern horn of Taurus.

To the upper left of Mercury, Mars is marching eastward in Gemini.  After its close opposition during October 2020, the planet has dimmed considerably as our planet moves farther away.

A binocular may help spot the starry background as the moon continues to wax and brighten.

The Red planet is 3.4° to the upper right of Mekbuda (ζ Gem), “the folded paw of the lion,” and 3.5° to the lower right of Wasat (δ Gem), “the middle of the sky.”  Wasat is close to the ecliptic, like Regulus in Leo.  The moon and bright planets pass near these stars.

The planet is below Castor and Pollux, the stellar pair that marks the heads of the Twins.

Here’s more about Mars during 2021.

Find a detailed chart of the motion of Mars during the month here.

The bright moon, 55° up in the southwest, is 4.9° to the upper left of Regulus, “the prince,” the brightest star in Leo.  The constellation consists of a backwards question mark and a triangle.  The backwards question mark is known as the “Sickle of Leo,” a farmer’s cutting tool and makes a silhouette of the big cat’s head.  The triangle marks the lion’s haunches with the tail, Denebola.

As the moon continues to wax, the dimmer stars become more difficult to see with the brighter moonlight.

At the latitude of Chicago, Venus sets 71 minutes after sunset. Mercury follows less than 45 minutes later.  Mars sets less than four hours after sunset and about 90 minutes before Saturn rises in the southeastern sky.

The five-planet display continues tomorrow, although Mercury is dimming each evening.

Detailed Note: One hour before sunrise, Jupiter is nearly 24° above the southeast horizon.  It is 2.0° to the upper left of ι Aqr and 4.6° to the lower right of θ Aqr.  Saturn is 17.0° to the upper right of bright Jupiter.  Saturn begins to retrograde in a few mornings.  It is 0.6° to the right of θ Cap.  The moon reaches its First Quarter phase at 2:13 p.m. CDT. Thirty minutes after sunset, brilliant Venus is nearly 7° above the west-northwest horizon. Use a binocular to find Mercury (m = 0.7), 7.5° to the upper left of Venus. The moon (8.3d, 53%) is nearly 60° up in the southwest. Fifteen minutes later, Venus is over 4° above the horizon, while Mercury is nearly 11° up in the west-northwest.  Mars – over 27° up in the west – is nearly 25° to the upper left of Mercury. The moon is 4.9° to the upper left of Regulus. One hour after sunset, Venus is just above the horizon. Mercury is nearly 7° up in the sky. Use a binocular to see Mars 3.4° to the upper right of ζ Gem and 3.5° to the lower right of δ Gem.

Read more about the planets during May 2021.



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