2022, June 20:  Morning Planet Parade Visibility

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June 20, 2022: Mercury, Venus, Mars, Jupiter, and Saturn are aligned in a planet parade before daybreak. How frequently are the five bright planets visible in their order from the sun before sunup? 

Chart Caption – 2022, June 20: The five bright planets are in order from the sun in the eastern sky before daybreak.

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by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:16 a.m. CDT; Sunset, 8:29 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

The sun has reached its earliest sunrise time and has started to get later.

 Morning Sky

SUMMARY OF PLANETS IN 2022 MORNING SKY

The five bright planets are in order from the sun in the eastern sky before sunrise.  Look for the bright moon, 58% illuminated, about one-third of the way up in the sky in the southeast.

That “bright star” to the upper left of the lunar orb is Jupiter.  Dimmer Mars is 13.0° to the lower left of the Jovian Giant.

Saturn, over 30° up in the south, is over 25° to the right of the moon.

Find a clear horizon to spot the Morning Star Venus, over 10° above the east-northeast horizon, Mercury is 9.7° to the lower left of Venus.

There they are, the five bright planets, visible in order from the sun.

What follows is the description of how this occurs.

Visibility of the Five Planets

How frequently are the planets lined up in order – Mercury, Venus, Mars, Jupiter, and Saturn – from the sunrise point westward and visible simultaneously?

The first clue is found in Jean Meeus’ book More Mathematical Astronomy Morsels.  The author lists when the five planets were visible simultaneously in any order from 1980 through 2020.  During this interval, the parade of five planets occurred about every two years in both the morning and evening sky, twelve such occurrences during the interval in a seven to five morning to evening split.

Meeus qualifies his list for observations at 40° north latitude and the planets are visible before sunrise, where the sun is at least 5° below the horizon and Mercury and Saturn are at least 5° up in the sky.

Photo Caption – 2012, August 14: On conjunction evening, Mars is 2.7° to the lower left of Saturn. Spica is nearby.

The displays occur near the times of the Great Conjunctions of Jupiter and Saturn, either four to five years before or after these rare celestial meetings. From 1985 to 1995, no parades occurred, the same for 2005 through 2015. Jupiter and Saturn were too far apart.

So, planet parades of any combination occur about every other year for a span of ten years, centered on the Great Conjunctions, followed by decade-long periods of no displays of five planets simultaneously.

In Meeus’ list, he highlighted a parade of five planets in the morning sky, that were in planet order.  This occurred during late 2004 and early 2005.

Photo Caption – 2020, December 20: Jupiter and Saturn (140 mm).

Other clues point us to possible dates:  After a Jupiter – Saturn conjunction, Jupiter is east of Saturn – to the left of Saturn in the northern hemisphere.  For the in order five-planet display to have a chance of occurring, Jupiter and Saturn must be relatively close in the sky.

Photo Caption – 2020, March 17: The moon approaches Jupiter and Mars as Mars closes in for its March 20 conjunction with Jupiter.

Secondly, a display can occur when Mars is east of Jupiter, after a Jupiter – Mars conjunction. Five-planet displays can occur in the ten-year windows, but they are not in order.  The wrinkle is getting Mars between Venus and Jupiter.  This appears to be the rare factor that makes the in-order planet display.

Thirdly, Saturn is still in the morning sky.  This occurs before its opposition with the sun.

Photo Caption – 2020, November 18: Forty-five minutes before sunrise, Venus is 4.3° to the left of Spica in the east-southeastern sky. Mercury is 13.4° to the lower left of Venus.

Fourthly, Venus and Mercury are past their inferior conjunctions and Mercury is near its greatest elongation.  Venus must appear farther away from the sun than Mercury.  This is not a large issue unless Saturn is nearing its opposition and soon drops from the morning sky in the west.  Mercury moves fast enough over a few days to change the Mercury – Venus order in the parade if Venus’ separation from the sun is within 30°.

Noting conjunctions of Venus with either Mars, Jupiter, or Saturn is unnecessary.  If this trio has a separation from the sun greater than 47°, then no conjunctions with these three planets occur.

Looking back in time to the 1961 conjunction and advancing it forward to the 2100 conjunction, here are five-planet displays with the planets in order from the sun in the morning sky:

  • August 1966, the planets spanned 114°, although Mercury, Venus, Mars, and Jupiter were only 12° apart in the eastern sky.
  • December 2004/January 2005, the planets, in order from the sun, spanned 136°.  The Jupiter – Saturn gap was 81°.
  • June 2022, the planets span 130°.  The Jupiter – Saturn gap is 41°.
  • January 2101, Jupiter and Saturn span 81.2°.

Note this qualification of the answer for southern hemisphere observers: During March 2041, Mercury, Venus and Mars are within an 11-degree circle before sunrise, but Mercury is only 15 degrees from the sun, below the ecliptic, and rising only 20 minutes before sunrise at Chicago’s latitude.  This is on the southern hemisphere’s list of in-order planet parades.  Mercury rises nearly an hour before sunrise from the ecliptic’s sharp angle with the horizon and the Mercury, Venus, Mars bunching is visible.

During this short interval of astronomical time (1961-2100), in the morning sky, the display of morning planets in order from the sun occurs every other Great Conjunction for the seven conjunctions surveyed for northern hemisphere observers.

Tomorrow, we look at the evening visibility of the five bright planets simultaneously and in order from the sun.

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