Tag: Mercury

2019: November 21-30: Venus-Jupiter Conjunction, Venus and the Moon & Moon, Mars and Mercury

Morning Sky

The moon passes two bright planets at the end of November.  Start watching on November 21 as the moon approaches them.  Notice each morning that the moon is lower in the sky and its crescent is thinner as it approaches its New Moon phase.

  • November 21: An hour before sunrise, the thinning moon, 32% illuminated, is 50° up in the southeast, is nearly 8° to the lower right of Denebola, the Tail of Leo. Mars is below the moon, over 13° up in the east-southeast. Fifteen minutes later, Mercury is nearly 7° up in the east-southeast.

  • November 22: An hour before sunrise, the crescent moon, 21% illuminated, is about 40° up in the southeast, 5.5° above the star. At the same time, Mars is below the moon, about 13° up in the east-southeast. Mercury is over 5° up in the east-southeast, about 10° to the lower left of Mars.

  • November 23: One hour before sunrise, the moon, 12% illuminated, is nearly 8° to the upper left of Spica. Mercury is over 6° up in the east, over 9° to the lower left of Mars.

  • November 24: One hour before sunrise, the thin crescent moon, only 6% illuminated, is 3.7° to the upper left of Mars, 15° up in the east-southeast. Mars is about midway between Spica and Mercury; Mercury – Mars, 9.5°; Mars – Spica, 9.7°. Tomorrow morning, at the closest approach, Mercury and Mars have about the same separation.

Evening Sky

Venus passes Jupiter on November 24, A few evening evenings later the crescent moon passes Venus for its closest approach during this appearance of Venus.

  • November 24: This evening is the Venus – Jupiter conjunction! Forty-five minutes after sunset, Venus, nearly 7° up in the southwest, is 1.4° to the lower left of Jupiter . The next Venus – Jupiter conjunction is February 11, 2021 when the planets are less than 0.5° apart, but this Epoch (close) Conjunction occurs during bright morning twilight. On April 30, 2022, another morning Epoch Conjunction brings the planets within 29’ of each other.

  • November 28:  In the evening, at mid-twilight (about 45 minutes after sunset), Venus (−3.9) and the moon, 6% illuminated) have a classic appearance, with Venus 1.9° to the lower right of the moon. This is the smallest separation between the moon and Venus during this apparition of the planet. Next month, the Moon – Venus gap is 2.4° and widens each month thereafter during this appearance. Venus and the moon appear in the viewfinder of a camera with a 300 mm focal length lens. A longer exposure reveals Earthshine on the moon. At this time, Venus is about 7° up in the southwest and 4.7° to the upper left of Jupiter. The moon is 5.8° to the upper left of Jupiter.

Day-By-Day Description

This text was first published in the TCAA Observer.

  • November 21: An hour before sunrise, the moon (24.3d, 32%), 50° up in the southeast, is nearly 8° to the lower right of Denebola (β Leo, m =2.1). Mars is below the moon, over 13° up in the east-southeast. Fifteen minutes later, Mercury (m = 0.1) is nearly 7° up in the east-southeast. Thirty minutes after sunset, Venus, over 8° up in the southwest, is8° to the lower right of Jupiter.
  • November 22: An hour before sunrise, the crescent moon (25.3d, 21%) is about 40° up in the southeast, 5.5° above Gamma Virginis (γ Vir, m = 3.4). At the same time, Mars is below the moon, about 13° up in the east-southeast. Mercury (m = − 0.1) is over 5° up in the east-southeast, about 10° to the lower left of Mars. Thirty minutes after sunset, the Venus – Jupiter gap is 2.1°. Venus is over 8° up in the southwest.
  • November 23: The moon is at perigee at 1:41 a.m. CST, 227,867 miles away. One hour before sunrise, the moon (26.3d, 12%) is nearly 8° to the upper left of Spica. Mercury (m = −0.2) is over 6° up in the east, over 9° to the lower left of Mars. Today Venus moves into Sagittarius. Thirty minutes after sunset, Venus, nearly 9° up in the southwest, is 1.5° to the lower left of Jupiter.
  • November 24: One hour before sunrise, the crescent moon (27.3d, 6%) is 3.7° to the upper left of Mars, 15° up in the east-southeast. Mars is about midway between Spica and Mercury (m = −0.4); Mercury – Mars, 9.5°; Mars – Spica, 9.7°. Tomorrow morning, at the closest approach, Mercury and Mars have about the same separation, although the gap is neither a conjunction nor a quasi-conjunction. At a quasi-conjunction, the planets are within 5°. At a conjunction, they must pass each other in either Right Ascension or ecliptic longitude. Today is the Venus – Jupiter conjunction! Forty-five minutes after sunset, Venus, nearly 7° up in the southwest, is 1.4° to the lower left of Jupiter (m = −1.8). The next Venus – Jupiter conjunction is February 11, 2021 when the planets are less than 0.5° apart, but this Epoch (close) Conjunction occurs during bright morning twilight. On April 30, 2022, another morning Epoch Conjunction brings the planets within 29’ of each other. Tonight, Venus sets at its southern-most azimuth, 236°. It sets here until December 1. The planet is nearly 1.5° below the ecliptic. Jupiter sets at Astronomical Twilight (sun’s altitude, −18°), 98 minutes after sunset.
  • November 25: One hour before sunrise, Mars (m = 1.7) is 15° up in the southeast, 9.5° to the upper right of bright Mercury (m = −0.3), 7° in altitude. The thin crescent moon (28.3d, 2%) is 5.5° to the lower left of Mercury. You’ll need a clear horizon to see the moon. It’s only 3° in altitude. Forty-five minutes after sunset, Venus, over 7° up in the southwest, is 2.0° to the left of Jupiter. Fifteen minutes later, Saturn is 17° up in the southwest, 19° to the upper left of Jupiter.
  • November 26: One hour before sunrise, Mars, nearly 15° up in the east-southeast, is nearly 10° to the upper right of Mercury (m = −0.5). The moon is at its New phase at 9:06 a.m. CST. As evening twilight progresses, attempt to locate Venus 0.6° to the lower left of the Lagoon Nebula (M8, NGC 6530). This is certainly a stretch with the nebula low in the sky and during latter twilight. Venus is 5° up in the southwest, 1 hour after sunset. It is 2.8° to the upper left of Jupiter. This evening Venus sets at the end of twilight when the sun is 18° below the horizon. Venus sets after the end of evening twilight until May 19, 2020.
  • November 27: One hour before sunrise, Mercury, over 7° up in the east-southeast, is 2.1° to the upper left of Zubenelgenubi (α Lib, m = 2.8). Use a binocular. Watch Mercury pass the star and move away from it during the next few mornings. At the same time, Mars is nearly 10° to the upper right of Mercury. Thirty minutes after sunset look for the crescent moon (1.3d, 2%), about 5° up in the southwest. It is nearly 11° to the lower right of Venus, with Jupiter between them, but Jupiter is closer to Venus. The planets are 3.7° apart.
  • November 28: Mercury reaches its greatest morning elongation (20.1°) at 4:27 a.m. CST. One hour before sunrise, Mercury (m = −0.6), about 7° up in the east-southeast, is 2.1° to the upper left of Zubenelgenubi. This morning’s distance is slightly larger than yesterday’s separation, when fractions of a degree are considered. Mars is over 10° to the upper right of Mercury. In the evening, at mid-twilight (about 45 minutes after sunset), Venus (−3.9) and the moon (2.3d, 6.3%) have a classic appearance, with Venus 1.9° to the lower right of the moon. This is the smallest separation between the moon and Venus during this apparition of the planet. Next month, the Moon – Venus gap is 2.4° and widens each month thereafter during this appearance. Venus and the moon appear in the viewfinder of a camera with a 300 mm focal length lens. A longer exposure reveals Earthshine on the moon. At this time, Venus is about 7° up in the southwest and 4.7° to the upper left of Jupiter. The moon is 5.8° to the upper left of Jupiter.
  • November 29: One hour before sunrise, Mercury, over 6° up in the east-southeast, is 2.6° to the lower left of Zubenelgenubi. Mars is over 10° to Mercury’s upper right. Venus is at its most southerly declination, −24.8°. One hour after sunset, this brilliant planet is over 6° up in the southwest and over 5° to the upper left of Jupiter. The moon (3.3d, 12%) is 14° up in the southwest, 1.7° to the lower left of Saturn.
  • November 30: One hour before sunrise, Mars, 15° in altitude in the southeast, is 0.2° to the lower left of Lambda Virginis (λ Vir, m = 2.8). Mercury is nearly 11° to Mars’ lower left. The speedy planet is 3.6° to the lower left of Zubenelgenubi. In the evening, Jupiter, Venus, Saturn, and the crescent moon span over 31°. Forty-five minutes after sunset, Venus is over 8° up in the southwest. Venus passes 0.8° to the upper right of Kaus Borealis (λ Sgr, m = 2.8), the star at the top of the lid of the Teapot of Sagittarius. Through a telescope, Venus is 11.6” in diameter and 89% illuminated. Jupiter is nearly 7° to the lower right of Venus. Jupiter continues its eastward crawl toward Saturn, over 18° to Jupiter’s upper left. The crescent moon (4.3d, 20%), 22° up in the southwest, is over 13° to the upper left of Saturn.

 

2019, November 11-20: Mercury Transit & Morning and Evening Planets

Morning Sky

Mars is low in the eastern sky about 1 hour before sunrise near the star Spica.  The planet is dimmer and redder than blue Spica.  During the next several mornings watch Mars move away from Spica.  The chart above shows the planet and the star about one hour before sunrise.  Both are low in the east-southeast.

Begin looking for the moon in the western sky during pre-sunrise hours on November 12.  On the morning of Nov 14, notice that the bright moon is above Aldebaran and the “V” of Taurus.

During these morning hours, watch the moon appear farther east and higher in the sky each morning.

Mercury begins a morning appearance.  On November 20, it is low in the east-southeast about one hour before sunrise.  Find a clear horizon to see it.

Evening Sky

Venus becomes easier to see if you look early enough.  The chart above shows the early evening sky, about 30 minutes after sunset on November 11.  Venus closes in on Jupiter for a November 24 conjunction.  This evening Venus and Jupiter are 13° apart.  Saturn is dimmer and farther to south.  It will become visible as the sky darkens further.

The bright moon is in the eastern sky during evening hours November 11 – 16.  Look for it in the east, beginning one hour after sunset on November 11.  Each night look one hour later.  It appears in the eastern sky each night, with a slightly different phase, and in front of other stars.

By November 20, brilliant Venus is 3.9° to the lower right of Jupiter.  Look shortly after sunset.  Find a clear horizon.

Daily Notes

The notes were originally published in the Observer.

  • November 11: One hour before sunrise, Mars, over 10° up in the east-southeast, is 2.9° to the left of Spica. Mercury transits (crosses) the sun’s disk today. This is a slow-moving event, about 5.5 hours long as the sun rises higher into the sky. Mercury is moving east to west when it is between Earth and sun. So the planet appears to move from the lower left to the upper right on the sun’s face. Mercury is 10” across, only slightly smaller in apparent size than Venus current angular diameter and three times larger than Mars. The transit begins a few minutes before sunrise (6:37 a.m. CST). By 9:20 a.m. the planet is in the center of the sun’s disk when the sun is about 20° in altitude in the southeast. (At 9:22 a.m. Mercury is officially at inferior conjunction, moving toward the morning sky.) When the sun is in the south at 11:40 a.m. CST, Mercury is nearing the upper right limb of the sun. Shortly after noon (12:02 p.m. CST), the full disk of Mercury last appears in front of the sun. The solar disk is over 30° up in the southern sky. The planet completely leaves the sun’s face two minutes later. The next two transits of Mercury (November 13, 2032, and November 7, 2039) are not visible from Central Illinois. Both start after midnight and end before sunrise. The next transit of Mercury that is visible from the area occurs on May 7, 2049, when the transit begins at 6:03 a.m. CDT (if daylight saving time exists then) and ends at 12:44 p.m. CDT. One hour after sunset, the moon (14.8d, 100%) is about 11° up in the east. The Pleiades have about the same altitude as the bright moon; they are about 20° to the left of the lunar orb.
  • November 12: One hour before sunrise, Mars, over 10° in altitude in the east-southeast, is 3.1° to the left of Spica. At the same time, the moon (15.3d, 100%) is 8° up in the west. If you can see dimmer stars, the Pleiades are nearly 15° above the moon. The moon is at its Full phase at 7:34 a.m. CST. One hour after sunset, the moon (15.8d, 100%) is 5° up in the east-northeast.
  • November 13: One hour before sunrise, Mars is over 11° up in the east-southeast, 3.4° to the lower left of Spica. The moon (16.3d, 99%) is farther west at this time, about 20° up in the west. It is about 10° to the lower right of Aldebaran (α Tau, m = 0.8). Thirty minutes after sunset, the Venus – Jupiter gap is over 10°. Venus is 6° up in the southwest. Two hours after sunset, the moon (16.9d, 98%) is nearly 9° up in the east-northeast. It is at the top of the “V” of Taurus, which is on its side when it rises. The bright moon is between Aldebaran and Epsilon Tauri (ε Tau, m = 3.5), and closer to the dimmer star, about 0.7° to its lower right. Use a binocular to see the dim star with the very bright moon. The moon is 2.3° to the upper right of Aldebaran. Look for the moon in the west in the morning and notice how far it moved in its orbital pathway compared to the starry background.
  • November 14: One hour before sunrise, Mars, 11° up in the east-southeast, is 3.9° to the lower left of Spica. Through a binocular notice that Mars, 76 Virginis (76 Vir, m = 5.2), and Spica are nearly in a line. The dimmer star is nearly midway between Mars and Spica. The moon (17.3d, 96%) is in the west again this morning, about 30° up. It is 4.6° to the upper right of Aldebaran. In the evening, about 30 minutes after sunset, Venus is less than 10° to the lower right of Jupiter. At this hour Venus is nearly 7° up in the southwest. Three hours after sunset (about 7:30 p.m. CST), the moon (17.9d, 93%), about 12° up in the east-northeast, is 2.4° to the upper right of Zeta Tauri (ζ Tau, m = 3.0), the Southern Horn of Taurus. Observe the star with a binocular. Compare the moon’s position in the morning. If you’re up late, the moon passes about 0.5° above the star at 12:30 a.m. CST tomorrow morning.
  • November 15: One hour before sunrise, the moon (18.3d, 91%), about 40° in altitude in the west, is 1.9° above Zeta Tauri. Mars, nearly 12° up in the east-southeast, is 4.3° to the lower left of Spica. Mercury (m = 2.6) is rapidly moving into the morning sky. For the next week it rises, on average, about 7 minutes earlier each morning. This morning it is 10° west of the sun. Rising about 45 minutes before sunrise, Mercury is at the horizon about 30 minutes before sunrise. During the daytime, the sun is in the sky a few minutes longer than 10 hours. Darkness, the time between the end of evening twilight and the beginning of morning twilight, is 10.75 hours long. Thirty minutes after sunset, Venus (m = −3.9) is 7° up in the southwest, about 9° to the lower right of Jupiter. As the sky darkens further, Jupiter, nearly 9° up in the southwest, is about 20° to the lower right of Saturn. The Ringed Wonder is 20° up in the south-southwest. Four hours after sunset (about 8:30 p.m. CST), the moon (19.0d, 87%) is 0.7° to the lower left of Mu Geminorum (μ Gem, m = 2.8). As the moon leaves the early evening sky, this month’s deep sky focus is the Helix Nebula (NGC 7293). With the gems of the autumn sky – in the names of M31, M15, h Persei, and χ Persei – nearing the meridian, it’s easy to overlook the Helix Nebula – a planetary nebula. It is the remnants of an exploded star that pushed off its outer layers when the stellar core generated too much heat. It is in the dimmer starfield of Aquarius, nearly in the middle of a triangle shaped by Fomalhaut, Delta Capricorni, and Delta Aquarii. The target is 1.1° to the right of Upsilon Aquarii (υ Aqr, m = 5.2). The nebula is large, about half the size of the moon. At this hour it is nearly 30° up in the south, but 10° east of the meridian. If all the light from the nebula were collected into a single stellar point, it would shine at 6th In his Celestial Handbook, Robert Burnham describes the nebula’s appearance. “The ‘Helix Nebula’ is usually regarded as the largest and nearest of the planetary nebulae. Despite its large size the nebula is faint and has a low surface brightness. Binoculars will show the object as a large circular hazy spot, and it is not a difficult object for a small telescope if a low power ocular is used. A rich-field instrument with a wide-angle eyepiece is the ideal telescope for objects of this type” (pp. 192-194). The helix shape appears in short exposure photographs. A dim, 13th magnitude star is at the center of the nebula. From my limiting magnitude estimates, you’ll need at least a 5-inch telescope to see it and some averted vision. Of course, the larger the light collector, the easier it is to locate the central star. In Deep Sky Wonders, Walter Scott Houston reports on observing conditions and instruments that various sky watchers used to view the Helix. He summarizes that small apertures and low powers are best to see the nebula. When larger ‘scopes were used, observers needed filters to reduce the sky glow. Additionally, many observers reported only seeing a uniformly round shape, not the helix shape with the dark center seen in photographs. Can you see the dark center of the nebula? What were the observing conditions and the telescope/eyepiece used?

At mid-month, when morning twilight begins (about 5 a.m. CST), Sirius, Orion’s Belt, Aldebaran, and the Pleiades are lined up in the western sky at nearly the same altitude. The bright gibbous moon is above them in Gemini. Procyon and Capella stand at nearly the same altitude as the moon on November 16th. Leo is farther east. Its great Sickle has not yet reached the meridian. The head of Hydra, the Snake, is at the meridian. Six 3rd and 4th magnitude stars outline the snake’s head. They are nearly 60° up about halfway between Procyon and Regulus. The snake wiggles eastward below Crater and Corvus. The tail goes below the horizon ending near Libra. Alphard, the “Solitary One,” is Hydra’s brightest star, over 20° to the lower right of Regulus and nearly 40° up in the south. It is a second magnitude star, the brightest in this part of the sky. Farther eastward along the ecliptic from Leo, Spica is low in the southeast, with Mars nearby. With Spica in the southeast, Arcturus is nearly 20° up in the east. The Big Dipper is high in the northeast with its curved handle guiding us to Arcturus. Cassiopeia is low in the north-northwest. Mars continues as a not-so-bright star, moving slowly in Virgo. Mercury pops into the morning sky as the second half of the month progresses, brightening as the apparition proceeds. Watch it move toward Mars, but there is no conjunction. Mercury has a nice appearance with Zubenelgenubi, but the star is low in the sky. Find a clear horizon and use a binocular to find the star. At the end of evening twilight (about 6 p.m. CST), the Summer Triangle – Vega, Altair, and Deneb – stands high in the southwest. Jupiter is low in the southwest with Saturn, in eastern Sagittarius, to Jupiter’s upper left. The Great Square of Pegasus approaches the meridian, high in the south. The square’s pair of western stars point downward to Fomalhaut that is less than one-fourth of the way up in the southern sky. The great Winter Congregation is now making its way into the evening sky, with the Pleiades leading the way from low in the east-northeast. Aldebaran is lower near the horizon. Capella is in the northeast, at about the same altitude as the Pleiades. The “fishhook” of Perseus hangs above Capella with Cassiopeia higher and above Pegasus toward the meridian. The Big Dipper may be hiding behind a neighbor’s house or other nearby building as it is low in the north-northwest. Venus continues to move toward Jupiter with a conjunction occurring in over a week.

  • November 16: One hour before sunrise, Mars, 12° up in the east-southeast, is 4.9° to the lower left of Spica. The moon (19.3d, 85%) is in western Gemini, over 50° up in the west. It is nearly at the intersection of a large “+” symbol. The vertical leg is from Betelgeuse (α Ori, m = 0.4) to Castor (α Gem, m = 1.6); the horizontal leg is from Procyon (α CMi, m = 0.4) to Capella (α Aur, m = 0.1). Venus is 25° east of the sun. Thirty minutes after sunset, it is 7° in altitude in the southwest, nearly 8° to the lower right of Jupiter. Five hours after sunset (about 9:30 p.m. CST), the moon (20.0d, 78%) is nearly 7° to the lower right of Pollux.
  • November 17: One hour before sunrise, the bright moon (20.3d, 76%), 60° up in the southwest, is nearly 6° to the lower left of Pollux.   Mars, over 12° up in the east-southeast, is over 5° to the lower left of Spica. About 30 minutes after sunset, Venus is over 7° to the lower right of Jupiter. Venus is about 7° up in the southwest. At about 10:30 p.m. CST, (6 hours after sunset), the moon (21.0d, 68%), about 13° up in the east-northeast, is 12° below Pollux and 3.4° to the upper right of the Beehive Cluster (M44, NGC 2632). If you’ve not seen the cluster, use the bright moon as a guide to locate it. Return with low powers when the moon is out of this part of the sky. Look at the moon and the cluster in the morning when the moon is closer.
  • November 18: One hour before sunrise, the moon (21.3d, 66%) is 1° above the Beehive Cluster. Farther east, Mars marches eastward in Virgo to the lower left of Spica and the planet is nearly 13° up in the east-southeast. Thirty minutes after sunset, the Venus – Jupiter gap is nearly 6° with Venus to Jupiter’s lower right. Venus is about 8° up in the southwest.
  • November 19: An hour before sunrise (about 5:45 a.m. CST), the moon (22.3d, 55%), 65° up in the south, is about 9° to the upper right of Regulus (α Leo, m = 1.3). At the same time, Mars is nearly 13° up in the east-southeast. Mercury is entering the morning sky. It is higher and brighter each morning. During the next few mornings, use a binocular until you can see this speedy planet without optical assistance. Forty-five minutes before sunrise, Mercury (m = 0.7) is nearly 6° up in the east-southeast, about 12° to the lower left of Mars. The moon reaches its Last Quarter phase at 3:11 p.m. CST. Thirty minutes after sunset, the Venus – Jupiter gap is about 5°. Venus is about 8° up in the southwest.
  • November 20: An hour before sunrise, the moon (23.3d, 43%), 60° up in the south-southeast, is nearly 7° to the lower left of Regulus. Mars is farther east at this hour, about 13° up in the east-southeast.   Fifteen minutes later, Mercury (m = 0.4) is nearly 11° to the lower left of Mars. Mercury is about 7° up in the east-southeast. Thirty minutes after sunset, the Venus – Jupiter gap is 3.9°. Venus is over 8° up in the southwest. Through a telescope, Venus is 11.2” across and 91% illuminated.

2019-2020: Mars Until it Retrogrades

Mars (NASA Photo)

 

This chart shows the rising time differences for the rising times of the bright planets and stars near the ecliptic and sunrise for up to five hours before sunrise. The moon’s time differences are displayed in circles. The setting times of Jupiter and Saturn are graphed compared to sunrise. (Data from the U.S. Naval Observatory)

(This article was first published in the Northern Lights Fall Issue)

Mars begins an apparition that takes it to an opposition on October 12, 2020, 808 days following its 2018 perihelic opposition. The opposition, that will be highlighted in a future issue, brings Mars to its closest approach about a week before opposition. On October 6, the closest approach is 35.8 million miles, about 8% farther away than the preceding close passing. This corresponds to a smaller disk presented through a telescope.

The chart above, compiled with data from the U.S. Naval Observatory, shows the morning sky for 13 months beginning August 1, 2019, from Chicago, Illinois. Time intervals are noted on the chart and in the daily notes. Specific times are for Chicago, Illinois. To observe locally, refer to local sources for the times of sunrise and sunset; apply the time differentials in the notes.

The chart displays the time differences between the time of sunrise and the rising times for other planets, moon, and bright stars near the ecliptic, for up to five hours before sunrise. The moon’s rising time difference is displayed with circles. The setting time differences for Jupiter and Saturn, compared to sunrise, are displayed as well. The three phases of twilight are graphed compared to sunrise, and conjunctions are identified. The chart also notes several dates when the moon is near the bright planets.

Mars, Jupiter, and Saturn have oppositions that occur within 91 days in 2020. The interest in the Mars opposition adds a highlight to the Great Conjunction of Jupiter and Saturn that occurs late in the year. Such Jupiter – Saturn conjunctions occur about every 20 years.

The apparent sizes of Mars (in arcseconds) at its oppositions are graphed from 1930 to 2050. The larger apparent sizes occur when Mars is near perihelion and smallest when it is near aphelion. The time between oppositions for Mars, Jupiter, and Saturn are displayed for some oppositions (in days). The Great Conjunctions of Jupiter and Saturn that occur about every 20 years are displayed with yellow stars, including the time (in days) between oppositions of the two planets.

Mars’ apparent size at opposition (24.3”) is 8% smaller than the 2018 perihelic opposition and 11% smaller than the 2003 close opposition. This was described above with the close approach that is farther away in 2020 than the most recent perihelic opposition. The chart above displays the apparent size of Mars at its oppositions from 1930 through 2050. The twenty-year intervals of the Jupiter – Saturn Great Conjunction are displayed with yellow stars along with the time interval between their oppositions. For several Mars’ oppositions, the time intervals are noted for the Bright Outer Planets – Mars, Jupiter, and Saturn.

In this summary the events before opposition include monthly passages of the moon that highlight the beginning of a lunar occultation that is easier to view in the Western US, conjunctions with Jupiter, Pluto, Saturn, Ceres, and Neptune.

The apparition began with Mars’ conjunction with the sun on September 2, 2019. While dim, it began a slow crawl into the morning sky. By mid-month Mars was rising at Civil Twilight when the sun was 6° below the horizon.

At the beginning of October, the Red Planet (m = 1.8) is just above the eastern horizon, 45 minutes before sunrise, although it is a binocular object. The planet continues to rise earlier, Nautical Twilight (sun’s altitude = −12°) on October 6. Throughout October it rises earlier, rising at Astronomical Twilight on October 25. In the summary, each entry includes the planet’s magnitude, apparent size, distance from Earth in Astronomical Units, and difference between the planet’s rising time and sunrise, stated in minutes. This time changes in the summary on July 1, 2020, when the difference noted is between sunset and the rising of Mars. Here’s what to look for:

  • October 26: (1.8, 3.7”, 2.56 AU, 94m) Forty-five minutes before sunrise, the waning crescent moon (27.6 days old, 4% illuminated) is 5.6° to the upper left of Mars, about 8° up in the east-southeast. At this time, Mars is 4.5° below Gamma Virginis (γ Vir, m 3.4). Use a binocular.
  • November 10: (1.8, 3.8”, 2.50 AU, 122m) One hour before sunrise, Mars, about 9° up in the east-southeast, passes 2.8° to the upper left of Spica (α Vir, m = 1.0).
  • November 24: (1.7, 3.9”, 2.42 AU, 146m) One hour before sunrise, the waning crescent moon (27.3d, 6%) is 3.7° to the left of Mars, 15° up in the east-southeast. At the same time Mars is 9.5° to the upper right of Mercury (m = −0.4). Tomorrow morning, at the closest approach, the planets have about the same separation, although the gap is neither a conjunction nor a quasi-conjunction.
  • November 25: (1.7, 3.9”, 2.42 AU, 148m) One hour before sunrise, Mars is 14° up in the southeast, 9.5° to the upper right of bright Mercury (m = −0.3), 7° in altitude. The thin crescent moon (28.3d, 2%) is 5.5° to the lower left of Mercury. You’ll need a clear horizon to see the moon. It’s only 3° in altitude.
  • November 30: (1.7, 3.9”, 2.39 AU, 156m) One hour before sunrise, Mars, 15° in altitude in the southeast, is 0.2° to the lower left of Lambda Virginis (λ Vir, m = 2.8).

December 2019

As the year closes, Mars continues its eastward march. Early in the month, bright Mercury is to the lower left of Mars. Still over 2 Astronomical Units from Earth, Mars moves through Libra and between the pincers of the Scorpion. The planet rises about 3 hours before sunrise, but it’s low altitude and southerly location may send you on a chase to find a clear horizon.

  • December 1: (1.7, 3.9”, 2.38 AU, 157m) Mars moves into Libra, 7.3° to the upper right of Zubenelgenubi (α Lib, m = 2.8). Sixty minutes before sunrise, Mars is about 15° up in the southeast.
  • December 12: (1.7, 4.0”, 2.32 AU, 174m) One hour before sunrise, Mars, over 17° up in the southeast, passes 0.2° to the upper left of Zubenelgenubi.
  • December 18: (1.6, 4.1”, 2.28 AU, 181m) One hour before sunrise, Mars, nearly 18° up in the southeast, is 0.7° to the lower right of Nu Librae (ν Lib, m =5.2). Use a binocular to see the pair.
  • December 21: (1.6, 4.2”, 2.25 AU, 184m) One hour before sunrise, Mars, 18° up in the southeast, is 2.3° to the upper left of Iota Librae (ι Lib, m = 4.5).
  • December 22: (1.6, 4.2”, 2.25 AU, 185m) One hour before sunrise, Mars, 18° in altitude in the southeast, is over 8° to the lower left of the waning crescent moon (25.7d, 15%). The moon is above a line that connects Zubenelgenubi and Zubeneschamali (β Lib, m = 2.6). The lunar crescent is 3.5° to the upper left of Zubenelgenubi.
  • December 23: (1.6, 4.2”, 2.24 AU, 191m) One hour before sunrise, Mars, 18° up in the southeast, is 6° to the upper right of the crescent moon (26.8d, 8%).

January 2020

As the New Year breaks, Mars is an unimpressive “star” low in the southeast as sunrise approaches, rising about 4 a.m. CST. It continues to move through Libra and Scorpius and into southern Ophiuchus. At mid-month it passes north of its Rival, Antares.

Notice on the rising chart above that the time differential between the rising of Mars and sunrise decreases from late January through early-April. The declination of the sun is greater than Mars’ position.  The sun is moving toward the vernal equinox while Mars is approaching the ecliptic’s lowest point. The basic principle is that the farther north an object the earlier it rises. During January and February, the time interval between sunrise and Mars rising decreases nearly 20 minutes. This is reflected in the dip the Mars rising line takes on the chart. The differential increases after Mars moves farther north in declination.

  • January 7, 2020: (1.5, 4.4”, 2.14 AU, 196m) One hour before sunrise, Mars, 19° up in the southeast, is 1° to the right of Graffias (β Sco, m = 2.5). Mars enters Scorpius today and moves through in only 8 days.
  • January 8: (1.5, 4.4”, 2.13 AU, 197m) One hour before sunrise, Mars, over 18° up in the southeast, passes 0.7° below Graffias.
  • January 9: (1.5, 4.4”, 2.12 AU, 197m) One hour before sunrise, Mars, over 18° up in the southeast, is still near Graffias, passing 0.1° from Omega1 Scorpii (ω1 Sco, m = 3.9). Use a binocular to see the planet with the dimmer starfield.
  • January 15: (1.5, 4.5”, 2.08 AU, 198m) Mars moves into Ophiuchus. It crosses the constellation in 27 days. One hour before sunrise, Mars is over 18° in altitude in the southeast, 1.8° to the upper right of Omega Ophiuchi (ω Oph, m = 4.4).
  • January 18: (1.5, 4.6”, 2.05 AU, 199m) One hour before sunrise, Mars, over 18° up in the southeast, is 4.7° to the upper left of Antares (α Sco, m = 1.0). At the same time, Mars is 0.4° below Omega Ophiuchi. View the star and Mars in the growing twilight with a binocular.
  • January 20: (1.4, 4.6”, 2.04 AU, 198m) One hour before sunrise, Mars is 18° up in the southeast, 3.9° to the lower left of the crescent moon (25.2d, 19%).
  • January 21: (1.4, 4.6”, 2.03 AU, 199m) One hour before sunrise, Mars, 18° up in the southeast, is over 9° to the upper right of the moon (26.2d, 11%).
  • January 24: (1.4, 4.7”, 2.00 AU, 198m) Mars is 2.0 Astronomical Units from Earth. One hour before sunrise, the Red Planet is 18° up in the southeast, 6.3° to the upper left of Antares.

February 2020

During February, Mars moves from Ophiuchus into Sagittarius, through the rich galactic background of our galaxy’s nucleus region. Use a binocular to track the planet’s motion. After mid-month, the moon occults Mars in a bright sky as sunrise approaches. Mars heads toward conjunctions with Jupiter, Pluto, and Saturn next month. Watch the gaps close during February as the Bright Outer Planets appear above the southeast horizon before sunrise.

  • February 1: (1.4, 4.8”, 1.94 AU, 197m) Mars moves south of the ecliptic. One hour before sunrise, find it about 18° up in the southeast.
  • February 2: (1.3, 4.8”, 1.93 AU, 196m) One hour before sunrise, Mars, about 18° up in the southeast, is 1° above Omicron Ophiuchi (ο Oph, m = 5.1).
  • February 4: (1.3, 4.9”, 1.92 AU, 195m) One hour before sunrise, Mars is over 17° in altitude in the southeast. It is 1.8° to the upper left of Theta Ophiuchi (θ Oph, m = 3.2).
  • February 5: (1.3, 4.9”, 1.91 AU, 194m) One hour before sunrise, Mars, over 17° up in the southeast, is 0.9° to the upper left of 44 Ophiuchi (44 Oph, m = 4.2).
  • February 6: (1.3, 4.9”, 1.90 AU, 194m) Mars rises at its most southerly rising azimuth, 122°, until March 5, 2020.
  • February 7: (1.3, 5.0”, 1.90 AU, 194m) One hour before sunrise, Mars, about 17° in altitude in the southeast, is 0.6° to the upper left of 51 Ophiuchi (51 Oph, m = 4.8).
  • February 9: (1.3, 5.0”, 1.88 AU, 193m) Mars is about 20° to the upper left of Jupiter (m = −1.9), 7° up in the southeast, one hour before sunrise.
  • February 11: (1.3, 5.0”, 1.86 AU, 192m) Mars moves into Sagittarius. It begins to approach the bright nebulae and rich star field above the Teapot of Sagittarius. Use low powers to view the planet and the starry background. As the moon approaches the region during the next week, watch Mars move between the Lagoon Nebula (M8, NGC 6523) and the Trifid Nebula (M20, NGC 6514). Mars crosses the constellation in 50 days.
  • February 17: (1.2, 5.2”, 1.81 AU, 189m) One hour before sunrise, Mars, nearly 17° up in the southeast, is about 13° to the lower left of the moon (23.6d, 33%).
  • February 18: (1.2, 5.2”, 1.81 AU, 189m) One hour before sunrise, the crescent moon (24.6d, 24%), about 17° up in the southeast, is 0.4° to the right of Mars. As sunrise approaches, the moon inches toward the planet. If you can track Mars into a brighter sky, the moon occults it a few minutes after 6 a.m. CST, about 35 minutes before sunrise in Chicago. Observers in the Western U.S. see the moon occult Mars in a darker sky.
  • February 26: (1.1, 5.4”,1.74 AU, 185m) One hour before sunrise, Mars, 16° up in the southeast, passes 1.8° to the upper left of Kaus Borealis (λ Sgr, m =2.8), the star at the top of the lid of the Teapot of Sagittarius.
March 20: Mars passes 0.6° to the lower right of Jupiter. Locate the planets in the southeast about an hour before sunrise.

March 2020

Mars marches eastward in Sagittarius, above the Teapot’s handle, and continues to rise earlier. By month’s end, the planet rises before 4 a.m. CDT, as the clock advances one hour on March 8. The gaps to Jupiter, Pluto, and Saturn close as Mars passes the planetary trio this month.

  • March 1: (1.1, 5.5”, 1.70 AU, 183m) One hour before sunrise, Mars, 16° up in the southeast, is 10° to the upper right of Jupiter (m = −2.0).
  • March 5: (1.1, 5.6”, 1.67 AU, 180m) One hour before sunrise, Mars, 16° up in the southeast, passes 2.9° to the upper left of Nunki (σ Sgr, m = 2.0) and appears nearly 8° to the upper right of Jupiter.
  • March 11: (1.0, 5.8”, 1.62 AU, 178m) One hour before sunrise, Mars, 16° up in the southeast, is 4.9° to the upper right of Jupiter. Gaps until the Jupiter – Mars conjunction: Mar 12, 4.3°; Mar 13, 3.7°; Mar 14, 3.3°; Mar 15, 2.7°; Mar 16, 2.2°; Mar 17, 1.7°, Mars to the right of Jupiter; Mar 18, 1.2°; Mar 19, 0.9°.
  • March 15: (1.0, 5.9”, 1.59 AU, 177m) One hour before sunrise, Mars, 16° up in the southeast, is 10° to the upper right of Saturn (m = 0.7).
  • March 18: (0.9, 6.0”, 1.56 AU, 174m) The crescent moon (24.1d, 29%) joins the scene with Jupiter and Mars. The trio makes a small triangle, the moon is 2.4° to the lower right of Jupiter and 2.2° to the lower left of Mars.

 

  • March 20: (0.9, 6.0”, 1.55 AU, 174m) Jupiter – Mars conjunction! Mars is 0.6° to the lower right of Jupiter. The gaps after the conjunction as Mars moves away from Jupiter: Mar 21, 0.9°; Mar 22, 1.3°; Mar 23, 1.7°; Mar 24, 2.3°; Mar 25, 2.7°; Mar 26, 3.4°; Mar 27, 3.9°; Mar 28, 4.5°; Mar 29, 5.0°. The next Jupiter – Mars conjunction is May 29, 2022 in the morning sky. At that conjunction the sky has 4 bright planets – Venus, Jupiter, Mars, and Saturn – in the southeastern sky. The moon is nearby, a few days before the closest Jupiter – Mars passage. This morning the Mars – Saturn gap is 7.1°.
  • March 23: (0.9, 6.1”, 1.52 AU, 174m) Mars passes 0.1° to the lower left of Pluto (m = 14.3). At the beginning of morning twilight, Mars is about 12° up in the southeast. This is clearly a stretch to see this conjunction. A big scope and ideal sky conditions are needed to locate the distant world near Mars.
  • March 26: (0.8, 6.2”, 1.50 AU, 173m) Mars is nearly equidistant from the two bright giant planets, although Mars is below a line that connects Jupiter and Saturn. One hour before sunrise, Mars, 15° up in the southeast, is 3.3° to the lower left of Jupiter and 3.2° to the upper right of Saturn. The Jupiter – Saturn gap is 6.4°.
March 31: Mars passes 0.9° to the lower right of Saturn. The planets are in the southeast about an hour before sunrise.
  • March 31: (0.8, 6.4”, 1.46 AU, 172m) Mars – Saturn conjunction! One hour before sunrise, Mars, 16° up in the southeast is 0.9° to the lower right of Saturn. The Mars – Saturn gap grows after the conjunction: Apr 1, 1°; Apr 2, 1.4°; Apr 3, 1.9°; Apr 4, 2.5°; Apr 5, 3.1°; Apr 6, 3.7°; Apr 7, 4.3°; Apr 8, 5.0°. This morning gap to Jupiter is 6.1°. Mars moves into Capricornus.

April 2020

Mars is now moving away from Jupiter and Saturn and through the starfield of Capricornus. Continue to track it with low powers as it passes dimmer stars. It has a close appearance with the moon at mid-month. By month’s end the planet rises before 3 a.m. CDT.

  • April 5: (0.7, 6.6”, 1.42 AU, 172m) One hour before sunrise, Mars, nearly 16° up in the southeast, is 5.1° to the lower right of Beta Capricorni (m = 3.0). Look for Saturn and Jupiter nearby.
  • April 7: (0.7, 6.7”, 1.41 AU, 172m). One hour before sunrise, Mars is 10° to the lower left of Jupiter and over 4° to the lower left of Saturn.
  • April 15: (0.6, 7.0”, 1.34 AU, 173m) One hour before sunrise, Mars, 16° up in the southeast, is nearly 10° to the left of the thick crescent moon (22.0d, 45%). At the same time, the moon is 3.3° below Saturn. This morning Jupiter is 5.5° to the upper right of Saturn and nearly 15° to the upper right of Mars.
  • April 16: (0.6, 7.0”, 1.34 AU, 173m) One hour before sunrise, Mars, over 16° up in the southeast, is 3.8° to the upper right of the crescent moon (23.0d, 36%). Mars is 10° to the lower left of Saturn.
  • April 20: (0.5, 7.2”, 1.30 AU, 174m) One hour before sunrise, Mars, nearly 17° up in the southeast, is 0.8° below Theta Capricorni (θ Cap, m = 4.0). In the brightening sky, use a binocular to see the star with Mars.
  • April 23: (0.5, 7.3”, 1.28 AU, 175m) One hour before sunrise, Mars, about 17° up in the southeast, is nearly 15° to the lower left of Saturn. Meanwhile, the Jupiter – Saturn gap is 5.1°.
  • April 25: (0.5, 7.4”, 1.27 AU, 177m) One hour before sunrise, Mars, over 17° up in the southeast, is 0.2° to the lower right of Iota Cap (ι Cap, m = 4.2). Optical assistance helps see Mars’ close proximity to the star.

May 2020

Mars moves from Capricornus into the dim star field of Aquarius early in the month, brightening about 45% as it nears 1.0 Astronomical Unit away. The planet is about 40 times brighter than the stars it passes during the month. Continue to use low power to track the planet on its eastward march. The moon passes at mid-month, although about a degree farther away than in April. The planet passes Ceres late in the month.  As April closes, Mars rises before 2 a.m.

  • May 1: (0.4, 7.7”, 1.22 AU, 180m) Ninety minutes before sunrise, Mars, 14° up in the southeast, 0.9° above Gamma Capricorni (γ Cap, m = 3.6).
  • May 4: (0.4, 7.8”, 1.20 AU, 183m) Mars is 1.0° to the upper left of Delta Capricorni (δ Cap, m = 2.8), 90 minutes before sunrise. The planet is over 14° up in the southeast.
  • May 9: (0.3, 8.0”, 1.16 AU, 187m) Mars moves into Aquarius. Ninety minutes before sunrise, locate it nearly 16° in altitude in the southeast. Mars crosses the constellation in 47 days.
  • May 11: (0.3, 8.1”, 1.14 AU, 188m) About 90 minutes before sunrise, Mars, about 16° up in the southeast, passes 0.3° to the upper right of Iota Aquarii. (ι Aqr, m = 4.2).
  • May 14: (0.2, 8.3”, 1.13 AU, 192m) About 90 minutes before sunrise, Mars, nearly 17° up in the southeast, is over 9° to the upper left of the slightly gibbous moon (21.3d, 52%).
  • May 15: (0.2, 8.3”, 1.12 AU, 193m) Mars is nearly 17° up in the southeast, ninety minutes before sunrise, 4.5° to the upper right of the moon (22.3d, 42%).
  • May 18: (0.2, 8.5”, 1.11 AU, 196m) One hour before sunrise, Jupiter is 27° up in the south. Saturn is 4.7° to the left of Jupiter. This is a quasi-conjunction. Saturn began retrograding May 11 and Jupiter May 18. This occurs over 7 months before the two planets’ Great Conjunction. At this time, Mars, 36° to the left of Jupiter, is 21° up in the southeast.
  • May 19: (0.2, 8.6”, 1.11 AU, 198m) Mars passes nearly 20° north of Fomalhaut (α PsA, m = 1.2). While not near the ecliptic, Fomalhaut is a bright beacon among the dimmer stars of this region. And its place helps note the passage of bright solar system objects. One hour before sunrise, Mars is 22° up in the southeast while the star is about 4° in altitude in the southeast.
  • May 21: (0.1, 8.7”, 1.08 AU, 201m) About 90 minutes before sunrise, Mars, over 18° up in the southeast, passes 0.8° to the lower right of Sigma Aquarii (σ Aqr, m =4.8).
  • May 24: (0.1, 8.8”, 1.06 AU, 205m) Ninety minutes before sunrise, Mars, over 19° up in the southeast, is 7° to the upper left of Ceres (1Ceres, m = 8.0), 1.2° to the lower right of Delta Aquarii (δ Aqr, m = 3.2).
  • May 25: (0.1, 8.9”, 1.05 AU, 207m) About 90 minutes before sunrise, Mars, over 19° up in the southeast, passes 3.5° above Tau Aquarii (τ Aqr, m = 4.0).
  • May 30: (0.0, 9.2”, 1.02 AU, 215m) Mars passes 1.9° to the lower right of Lambda Aquarii (λ Aqr, m = 3.7). Mars is over 20° up in the southeast, ninety minutes before sunrise.

June 2020

During the month, Earth moves within 1 Astronomical Unit of Mars, while the Red Planet’s brightness grows nearly 0.5 magnitude. The planet passes Neptune late in the month. As the month closes, Mars rises at about 12:30 p.m. CDT.

  • June 1: (0.0, 9.3”, 1.00 AU, 218m) Mars is 1 Astronomical Unit from Earth. Ninety minutes before sunrise the planet is 21° up in the southeast.
  • June 5: (−0.1, 9.6”, 0.98 AU, 225m) Mars is 90° west of the sun. Ninety minutes before sunrise, it is nearly 21° up in the southeast.
  • June 8: (−0.1, 9.8”, 0.96 AU, 232m) Ninety minutes before sunrise Mars is nearly 24° up in the southeast. With a binocular observe that it is 1.5° to the lower right of Phi Aquarii (φ Aqr, m = 4.2) and 0.3° to the upper left of Chi Aquarii (χ Aqr, m = 4.9).
  • June 13: (−0.2, 10.1”, 0.92 AU, 243m) Ninety minutes before sunrise, Mars, 26° up in the southeast, is 1.6° to the lower right of Neptune (m = 7.9) and 4.7° to the upper right of the moon (21.6d, 49%). Use higher powers to see Neptune’s 2.3”-diameter disk.
  • June 25: (−0.4, 11.0”, 0.85 AU, 276m) Mars moves into Pisces, below the six, fourth magnitude stars that make the western fish. Mars makes a partial passage through Pisces in 13 days, then it moves into Cetus. It is 0.2° to the upper right of 27 Piscium (27 Psc, m = 4.8). Ninety minutes before sunrise, Mars is 31° up in the southeast.

July 2020

The time differential in the notes changes to rising time after sunset. (On July 8, Mars rises in the east 221 minutes after sunset.) Earth begins to close in on Mars. Now brighter than all the stars, except Sirius from the Northern Hemisphere, Mars gleams from the southeast before morning twilight begins. It moves into Cetus for a short duration, still among dimmer stars. Continue to track it with a binocular, although larger scopes should start to bring in details visually. The morning sky has a planet parade of all the planets in the solar system. In addition to ruddy Mars, brilliant Venus joins, Jupiter and Saturn, although brilliant Venus shines from the eastern sky. Jupiter and Saturn pass opposition six days apart, then Mercury pops into the sky. This results in 5 naked eye planets in the sky at once. Additionally, the telescopic planets are there as well: Uranus, Neptune, and Pluto. (Historically, Pluto is a planet. Without too much description, we have many things in astronomy that are misnamed – like planetary nebula.)

  • July 8: (−0.6, 12.2”, 0.77 AU, 221m) Mars moves into Cetus. Mars moves across this corner of Cetus in 19 days, then back into Pisces. The constellations are not uniform in shape and size. The ecliptic is less than 1° from a corner of Cetus near coordinates Right Ascension, 0 hours, 26 minutes; Declination, 2°. Cetus also bounds Aries on the south, but Mars moves north of the ecliptic after opposition and it does not return to this constellation this apparition. Ninety minutes before sunrise (about 4 a.m. CDT in Chicago), it is 37° up in the southeast.
  • July 11: (−0.7, 12.4”, 0.75 AU, 215m) Two hours before sunrise, Mars, nearly 36° up in the southeast, is over 6° to the upper left of the moon (20.1d, 65%).
  • July 12: (−0.7, 12.5”, 0.74 AU, 212m) Mars rises before midnight CDT. Two hours before sunrise, Mars, 36° up in the southeast, is nearly 6° to the upper right of the moon (21.1d, 56%). At this time, brilliant Venus is nearly 6° up in the east-northeast, 0.9° to the upper left of Aldebaran (m = 0.8).
  • July 14: (−0.8, 12.7”, 0.74 AU, 209m) Jupiter (m = −2.8) is at opposition. One hour after sunset, Jupiter is 10° up in the southeast, nearly 7° to the upper right of Saturn. Later this night, at 1 a.m. CDT, July 15, Mars is 11° up in the east, 77° to the east of Jupiter, now 26° up in the south.
  • July 18: (−0.8, 13.1”, 0.71 AU, 200m) Mars is 105° west of the sun. Ninety minutes before sunrise, it is 42° up in the southeast.
  • July 19: (−0.8, 13.2”, 0.71 AU, 199m) Two hours before sunrise, Mars, nearly 40° up in the southeast, passes 2.2° to the upper left of 20 Ceti (20 Cet, m = 4.8). This morning and for the next week, look for the five naked eye planets simultaneously. Mercury rises higher in the eastern sky and brightens as Jupiter appears lower in the southwestern sky. This morning the thin crescent moon is part of the scene. Look for them 45 minutes before sunrise. The moon (28.1d, 2%) is about 5° up in the east-northeast. Dim Mercury (m = 0.8) is about 5° to the right of the moon at about the same altitude, only slightly higher in the sky. It’s a binocular object. Brilliant Venus (m = −4.4) is over 20° up in the east, 4.5° to the lower left of Aldebaran. By this time, Mars is over 45° up in the south-southeast. Saturn (m = 0.1) is 9° up in the southwest, 7° to the upper left of Jupiter that is just above the southwestern horizon. The five naked eye planets are in the sky simultaneously with the bonus of a thin crescent moon!
  • July 20: (−0.9, 13.4”, 0.70 AU, 197m) Saturn is at opposition. One hour after sunset, Saturn is 10° up in the southeast, about 7° to the lower left of Jupiter. As midnight approaches, Mars is about 3° up in the east, about 74° east of Saturn, now 26° up in the south-southeast.
  • July 24: (−0.9, 13.8”, 0.68 AU, 189m) Two hours before sunrise, Mars, nearly 42° up in the southeast, is 5.6° to the lower right of Delta Piscium (δ Psc, m = 4.4).
  • July 27: (−1.0, 14.1”, 0.66 AU, 184m) Mars moves back into Pisces. Two hours before sunrise, the planet is over 43° up in the southeast. Brilliant Venus is over 60° to the lower left of Mars.
  • July 31: (−1.1, 14.6”, 0.64 AU, 178m) Two hours before sunrise, Mars, 45° up in the southeast is 4.9° below Epsilon Piscium (ε Psc, m = 4.2).

August 2020

Mars, now back in the constellation Pisces, continues its eastward march, as its brightness grows. While Mars brightens, Venus dominates the morning sky. Mars passes perihelion on August 2.

  • August 2: (−1.1, 14.8”, 0.63 AU, 175m) Mars is at perihelion, 1.38 Astronomical Units from the sun. It is 45° from its position when it is at opposition, measured along its orbit. Mars rises before 10 p.m. CDT. As midnight approaches the plant is about 10° in altitude in the east.
  • August 9: (−1.3, 15.7”, 0.60 AU, 164m) Two hours before sunrise, Mars, nearly 50° up in the southeast, is 0.9° to the upper right of the moon (19.6d, 72%).
  • August 14: (−1.4, 16.4”, 0.58 AU, 155m) Two hours before sunrise, Mars, 52° up in the south-southeast, is 1.0° below Mu Piscium (μ Psc, m = 4.8).
  • August 23: (−1.6, 17.7”, 0.53 AU, 139m) Two hours before sunrise, Mars, over 50° up in the south, is 0.5° to the upper left of Nu Piscium (ν Psc, m = 4.4).

September 2020

Earth closes to within 0.5 Astronomical unit of Mars. The planet is now appearing above the eastern horizon before midnight. Mars slows and stops its eastward motion against the starry background.

  • September 2: (−1.8, 19.2”, 0.49 AU, 120m) Two hours before sunrise, Mars, 55° up in the south, is 3.6° to the upper right of Xi Piscium (ξ Psc, m = 4.6). In the evening, three hours after sunset (about 10:30 p.m. CDT in Chicago), Mars is 10° up in the east.
  • September 4: (−1.9, 19.5”, 0.48 AU, 117m) Mars is 135° west of the sun. Three hours after sunset, Mars is nearly 11° up in the east. The gibbous moon (17.0d, 92%) is over 12° to the upper right of the planet.
  • September 5: (−1.9, 19.6”, 0.48 AU, 115m) Two hours before sunrise, Mars, 54° up in the south-southwest, is 10° to the upper left of the moon (17.3d, 91%). In the evening, 3 hours after sunset, Mars – 11° up in the east – is 0.8° to the upper left of the moon (18.0d, 86%).
  • September 6: (−1.9, 19.8”, 0.47 AU, 112m) Two hours before sunrise, Mars, nearly 55° up in the south-southwest, is 2° to the lower right of the moon (18.3d, 85%). In the evening, three hours after sunset, Mars – 11° up in the east is nearly 12° to the upper right of the moon (19.0d, 79%).
  • September 8: (−2.0, 20.1”, 0.47 AU, 108m) Two hours before sunrise, Mars is 53° up in the south-southwest. This evening the planet rises before 9 p.m. CDT. Three hours after sunset, Mars is over 12° up in the east.
  • September 11: (−2.1, 20.4”, 0.46 AU, 101m) Mars eastward motion ends and it begins to retrograde. It is 141° west of the sun. Two hours before sunrise, the planet is 52° up in the south-southwest. In the evening, three hours after sunset, Mars is nearly 14° up in the east.

Until retrograde began, Mars passed four planets and a minor planet, and had an occultation with the moon. Earth is now closing in toward its closest approach and Mars’ opposition, about a month away. While not as close as the last perihelic opposition, the next opposition occurs farther north and promises great views. In a later issue, we pick up the story of Mars at opposition.

 

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2019, August 12-13: Perseid Meteor Shower Peak Dimmed by Bright Moon

Meteor Shower (NASA Photo)

Annual meteor showers occur when our planet passes through the dusty debris that are spread broadly along a comet’s celestial path.  Each year during mid-August, Earth passes through the track of Comet Swift-Tuttle.  Tiny bits of dusty rock smash into our planet’s atmosphere and are vaporized in a quick streak of light — a meteor or shooting star.  During this time, the meteors can be seen anywhere in the sky, but they seem to emerge from the region of the constellation Perseus in the northeastern sky during the early evening.  As Earth rotates during the night, the point of emergence (radiant) moves higher in the sky.  The best viewing occurs after midnight when the radiant is highest in the sky before morning twilight begins,

It is important to note that the rates that are published in the popular press include dim meteors and those that dazzle our eyes and temporarily leave a streaked glow in the atmosphere.  It is impossible for any one observer to see all the projected meteor counts.  Today many live in cities or larger metropolitan where the glow of bright streetlights wash out the dimmer nighttime stars and dimmer meteors during this shower.

So, for observers in metropolitan areas should half the projected rates (60 meteors per hour).  So we’re down to 30 meteors per hour for most observers in metropolitan areas.  To see the entire sky, the observer needs an all sky camera to catch all the meteors or four friends who look above the cardinal directions while the single observer looks overhead.  So, a lone observer can see 5-6 meteors per hour in a metropolitan area or 10-12 per hour in a dark location. So be patient, especially this year with a bright moon in the sky during the morning.

This year, a gibbous moon adds bright light, so the observable rate is reduced further to perhaps 2-3 in town, 4-6 away from lights.

Here are notes for the mornings of August 11-13 that include some planet observations.  Times are in Central Daylight Time for observers near Chicago Illinois.

  • August 11: The Perseid meteor shower is near its peak. The moon sets a few minutes after 2 a.m. CDT and morning twilight begins about 2 hours later.
  • August 12: Jupiter is now setting before 1 a.m. CDT. For the Perseids, moonset occurs near 3 a.m. CDT and morning twilight begins an hour later. Bright Mercury is 10° up in the east-northeast, 30 minutes before sunrise.
  • August 13: For the peak morning of the Perseids, the moon sets about 15 minutes before morning twilight begins. About 30 minutes before sunrise, Mercury, a little brighter than yesterday morning, is nearly 10° up in the east-northeast.

2019-2020: Venus as an Evening Star

August 4, 2018: Venus from the Arizona desert.

Link to our semi-technical analysis of this apparition.

Venus shines as a brilliant evening star during late 2019 and early 2020.  The apparition (appearance) includes conjunctions with Jupiter and Saturn that occur within a month.  Then Venus moves past Neptune and Uranus.  The appearance includes a close conjunction with the Pleiades and a quasi-conjunction (near conjunction) with Beta Tauri.  The apparition ends as Venus dives toward inferior conjunction and has a conjunction with Mercury, followed by a pretty grouping of the two planets, Beta Tauri, and the moon.

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The young lunar crescent’s appearance with Venus is always an exciting time to view and photograph the brilliant planet and the moon displaying Earthshine.  The best view occurs on November 28, when the pair is 1.9° apart.

Venus as an Evening Star. The chart shows the setting time of Venus and other celestial objects in the west compared to sunset.  Data from the U.S. Naval Observatory for Chicago, Illinois.

The chart above shows the setting time of Venus compared to sunset along with other bright stars near the ecliptic and the moon.  The chart is constructed from data from the U.S. Naval Observatory for Chicago, Illinois.   When the Venus line crosses the lines of other objects, they set at the same time.  A conjunction occurs near the intersection.  If a moon circle is near one of the setting lines, a conjunction may occur on that date, or on the day before or day after the date the moon and that object are plotted together.

It is important to note that because two objects set at the same time, they may not appear close together in the sky.  Two objects that are far apart in the sky can set at the same time.  Because objects have been selected for the chart that are near the ecliptic, close conjunctions might occur.  While Antares, Aldebaran, and Pollux generally lie near the ecliptic, the conjunctions with planets usually have gaps of several degrees.

Venus is at superior conjunction on August 14. 2019 when it is on the far side of the sun.

Venus passes superior conjunction at 1:07 a.m. CDT on August 14, 2019, nearly 1.3° north of the sun.  Because of the time, the conjunction is invisible in the Central U.S., but Venus can be found with optical assistance in a clear sky northeast of the sun after it rises that morning. Great care must be taken for visual observations of the planet in close proximity to the sun

Venus Emerges Into Bright Evening Twilight

Venus climbs into bright evening twilight in the southwestern sky and is soon visible in darker skies.  It is headed toward a conjunction with Jupiter in about a month.  On October 27, Venus is 20° from the sun and sets in the southwest and about an hour after sunset.

In the charts that follow, several of them are displayed for a time interval after sunset.  Use local sources for the time of your sunset.  The U.S. Naval Observatory has an online calculator that displays a year of sunrises and sunsets.  Enter your state and city into Form A on the website. Make appropriate changes for Daylight Saving Time.  For readers outside the U.S., enter your longitude and latitude in Form B for your yearly table.  Click here.

2019, October 29: Venus appears 4.7° to the lower right of the crescent moon. Jupiter is to the pair’s upper left. Find a clear horizon to locate Venus and the moon.

The moon makes its first appearance with Venus on October 29, as illustrated above.   Thirty minutes after sunset, the moon appears to the upper left of Venus, only 4° up in the southwest with bright Jupiter to the upper left of the pair. The moon is 1.8 days old, past its New phase, and 4.4% illuminated.  The moon appears with Jupiter two evenings later (October 31).  By early November, Venus continues to set later.  By November 4, it sets about an hour after sunset.

Venus – Jupiter Conjunction

For the second time during this apparition of Jupiter, Venus passes the Giant Planet.  Watch Venus move into Ophiuchus and then it passes Jupiter on the edge of Sagittarius. The next conjunction is February 11, 2021, but the planets rise during bright morning twilight.  On April 30, 2022, the planets rise into the eastern sky about 90 minutes before sunrise 29’ apart, an Epoch Conjunction.  During the current apparition, Venus and the moon have a very nice pairing (1.9°) near the end of November.  Follow the progress of the 2019 Venus – Jupiter conjunction during November:

On November 9, thirty minutes after sunset, Venus, nearly 6° up in the southwest, is 3.9° to the upper right of  the star Antares. The Venus – Jupiter gap is 15°. Venus continues to set later, appearing higher at the same time each evening.

2019, November 13: Venus is about 10° from Jupiter, 30 minutes after sunset.

By November 13, thirty minutes after sunset, the Venus – Jupiter gap is over 10°. Venus is 6° up in the southwest.  A few evenings later, November 16, Venus is 25° east of the sun. Thirty minutes after sunset, it is 7° in altitude in the southwest.

2019, November 19: Forty-five minutes after sunset. Brilliant Venus and Jupiter are 5° apart in the southwest.

Venus continues to close in on Jupiter.  By November 19, forty-five minutes after sunset, the Venus – Jupiter gap is about 5°. Venus is 4° up in the southwest. The separations until the conjunction: Nov 20, 3.9°; Nov 21, 2.8°; Nov 22, 2.1°; Nov 23, 1.5°, Venus is to the lower left of Jupiter.

2019, November 24: Venus-Jupiter conjunction. Look in the southwest about 30 minutes after sunset.

On November 24, Venus is closest to Jupiter! Forty-five minutes after sunset, Venus, nearly 7° up in the southwest, is 1.4° to the lower left of bright Jupiter. This evening, Venus sets at its southern-most azimuth, 236°. It sets here until December 1.  The Venus – Jupiter separations after conjunction: Nov 25, 2°, Venus is to the left of Jupiter; Nov 26, 2.8°; Nov 27, 3.7°, Venus is to the upper left of Jupiter; Nov 28, 4.7°.

On November 26, Venus sets at the end of twilight, over 90 minutes after sunset, when the sun is 18° below the horizon.  Venus sets after the end of evening twilight until May 19, 2020.

The next evening, November 27, thirty minutes after sunset look for the crescent moon (1.3d, 2%), about 5° up in the southwest. It is nearly 11° to the lower right of Venus, with Jupiter between them, but Jupiter is closer to Venus.

2019, November 28: Venus and the moon are very close, only 1.9° apart!. Jupiter is to the lower right of the Venus and Saturn is to the upper left.

On November 28, at mid-twilight (about 45 minutes after sunset) Venus and the moon (2.3d, 6.3%) have a classic appearance, with Venus 1.9° to the lower right of the moon. At this time, Venus is about 7° up in the southwest.  Both appear in the viewfinder of a camera with a 300 mm focal length lens.  A longer exposure reveals Earthshine on the moon.

2019, November 30: Venus passes Kaus Borealis, the star at the top of the lid of the Teapot of Sagittarius.

Venus continues to move away from Jupiter.  On November 30, Venus passes 0.8° to the upper right of Kaus Borealis, the star at the top of the lid of the Teapot of Sagittarius.

Venus – Saturn Conjunction

As Venus moves away from Jupiter, it approaches and passes Saturn. Watch Venus close the gap on Saturn and pass it on December 10. Venus passes Saturn again on February 6, 2021 in a difficult-to-see conjunction, just 5 days before the Venus-Jupiter conjunction of 2021.  On the morning of March 29, 2022, Venus is 2.1° from Saturn. Mars is nearby, 4.4° to the upper right of Saturn.

2019, December 2: Venus is about 10° to the lower right of Saturn.
  • The diagram above on December 2, 45 minutes after sunset, shows Venus about 9° up in the southwest. It is about 10° to the lower right of Saturn.  On the next evening, December 3, the three evening planets – Venus, Jupiter, and Saturn – are nearly equidistant tonight, but they are not along the same arc in the sky: Venus – Saturn, 8.6°; Venus – Jupiter, 9.7°.
2019, December 5, Venus passes the star Sigma Sagittarii. Venus is about midway between Jupiter and Saturn.

Venus continues to move eastward compared to the starry background toward Saturn.  On December 5,  Venus passes 1.9° to the upper right of Sigma Sagittarii.  Venus continues to close the gap on Saturn. Venus – Saturn separations until the conjunction: Dec 7, 4.3°, Dec 8, 3.3°; Dec 9, 2.4°.

2019: December 10: Venus passes Saturn.

Venus passes Saturn on December 10. At mid-twilight, Venus, over 11° up in the southwest, is 1.8° to the lower left of Saturn. Venus – Saturn gaps after the conjunction: Dec 11, 1.9°; Dec 12, 2.5°; Dec 13, 3.4°, Venus is to the upper left of Saturn; Dec 14, 4.4°, Dec 15, 5.4°. Venus continues eastward against the starry background, moving farther away from Saturn. on December 19, one hour after sunset, Venus, 12° up in the southwest, is nearly 10° to the upper left of Saturn. Venus moves into Capricornus.

2019, December 28: The crescent moon is 2.4° below brilliant Venus.

By the end of 2019, the crescent moon rejoins Venus.  One December 28, about an hour after sunset, Venus is about 15° up in the southwest. The moon (2.8d, 8%) is 2.4° below the planet.

Venus as an Evening Star in 2020

2020, January 15: Venus shines brightly in the western sky in early 2020.

Venus begins the New Year among the dimmer stars of eastern Capricornus.  Now setting abut 3 hours after the sun, watch Venus move eastward into Aquarius and toward a Neptune conjunction.

2020, January 27″ The moon appears near the star Phi Aquarii and the planet Neptune. A small telescope or binocular is needed to see Neptune that appears as a bluish “star.”

Venus continues moving eastward, appearing higher in the sky when it is completely dark.  By January 27, Venus is 40° east of the sun. At the end of evening twilight, Venus, 18° up in the west-southwest, is 0.2° to the upper left of Neptune, nearly 7° above the crescent moon (3.1d, 9%) and 0.2° to the lower right of Phi Aquarii.  A binocular or small telescope is needed to see Neptune.

On the next evening, January 28, at the end of evening twilight Venus, about 18° up in the west-southwest, is 7° below the moon (4.1d, 15%).

Venus Moves Into Pisces

During February brilliant Venus, still moving about 1.2° each day along the ecliptic, moves into Pisces and passes several dimmer stars.  The starry background is dim.

2020, February 26 & 27: The crescent moon appears near Venus.

By the end of February, the crescent moon is back in the evening sky.  On February 26, at the end of twilight, the moon (3.4d, 10%), 14° up in the west, is 10° to the lower left of Venus. On the next evening, February 27, at the end of evening twilight, Venus, 25° up in the west, is nearly 7° to the right of the waxing crescent moon (4.4d, 16%)

Venus Moves Through Aries: A Venus – Uranus Conjunction

During March, Venus crosses into Aries, passing far from the constellation’s brighter stars.  It is heading toward a conjunction with Uranus

2020, March 7: Venus passes Uranus. Use a binocular to locate the dimmer planet.

Venus closes in on the planet Uranus.  On March 7, Venus is 2.2° to the right of Uranus.  The planet is brighter than Neptune, which Venus passed in January.  In a dark sky, Uranus is visible in a dark sky to those with good eyesight.  Use a binocular to see it easier.

2020, March 24: Venus reaches its greatest separation from the sun as seen from Earth.

Venus continues to set later in the evening and appears farther from the sun.  On March 24, Venus is at greatest elongation (46.1°) at 5:13 p.m. CDT. We see Venus farthest from the sun during these evenings. At the end of evening twilight, Venus is over 25° up in the west.

2020, March 27 & 28: Venus closes in on the Pleiades as the moon passes by the brilliant planet.

As the weather warms in the northern hemisphere, Venus approaches the Pleiades star cluster.  Here we reference the Pleiades with its brightest star Alcyone (Eta Tauri)  The moon enters the region with Venus.  On March 27, Venus is nearly 10° to the upper right of the waxing crescent moon (3.7d, 12%) and 6.5° to the lower right of the Pleiades. Here are the gaps as Venus closes in on the star cluster: March 30, 3.6°; March 31, 2.7°; April 1, 1.8°; April 2, 0.9°, Venus is below Alcyone.

On March 28, at the end of evening twilight, Venus, 26° up in the west, is 8° to the lower right of the moon (4.7d, 18%) and 5.5° to the lower right of the Pleiades. The trio – Venus, Moon, and Pleiades – makes nearly an equilateral triangle. Venus sets at its maximum interval after sunset – 4 hours, 7 minutes, through April 7.

Venus in Taurus: A Spectacular Pleiades Conjunction

2020: Venus approaches and moves past the Pleiades star cluster during late March and Early April. The closest date is April 3, 2020 when the planet is 0.3° to the lower left of the star cluster.

In late March, Venus moves into Taurus, heading for a conjunction with the Pleiades. During April, Venus moves between the Pleiades and Hyades and toward Elnath (Beta Tauri, m = 1.6), the Bull’s northern horn.  As Venus approaches the star, it begins a rapid descent toward the western horizon, toward its early June inferior conjunction.

On March 30,  Venus moves into Taurus, 3.6° to the lower right of Alcyone, the brightest star in the Pleiades star cluster.  The next evening, March 31, at the end of evening twilight, Venus, over 25° up in the west, is 2.7° to the lower right of Alcyone.

As April opens Venus is in the west near the Pleiades.  On April 3, one hour after sunset, Venus, 30° up in the west, is 0.3° to the lower left of Alcyone.  This is the closest Venus gets to the Pleiades on this evening appearance.

On the next evening, April 4, on this evening and for the next few evenings Venus and Sirius are at nearly the same altitude in the west at about 9 p.m. CDT in Chicago, a few minutes after the end of evening twilight (about 105 minutes after sunset). While Venus and Sirius are too far apart for technical comparisons of their brightness difference, the brightest star and the brightest planet are the same altitude in the western sky. Sirius, Orion’s belt, Aldebaran, and Venus are nearly in a line across the western horizon. The Venus – Alcyone gap, 0.9°.  Gaps as Venus moves eastward along the ecliptic and away from the Pleiades: April 5, 1.8°; April 6, 2.7°; April 7, 3.5°; April 8, 4.6°; April 9, 5.2°.

Venus moves between the Pleiades and the Hyades.  On April 9, at the end of evening twilight, Venus, nearly 25° up in the west-northwest, is below a line that extends from Aldebaran to Epsilon Tauri.  Venus passes nearly nearly 7° to the upper right of Epsilon Tauri on April 12.

 

Venus appears at its greatest brightness when it is midway between its greatest elongation and its inferior conjunction.

Venus continues to brighten from its first appearance in the evening sky.  Beginning April 13,  Venus reaches its maximum brightness until May 10. The midpoint, April 27, is marked on the setting chart (GB) near the beginning of the article. While the planet may grow brighter, as measured with detailed light measurements through a telescope, our eyes likely cannot perceive the minute difference in brightness during this duration. The planet reaches its latest setting time 11:33 p.m. CDT in Chicago, 243 minutes after sunset.  This setting time continues until April 18.

Venus continues its climb through Taurus.  On April 14, one hour after sunset, Venus, 30° up in the west, passes nearly 10° to the upper right of Aldebaran.  A week later, April 21, Venus sets at its northern most setting azimuth (309°). It sets here until May 14.

2020, April 26: The moon is to the left of Venus among the stars of Taurus..

As Venus continues through Taurus, it moves toward Beta Tauri, the northern horn of the Bull. On April 26, One hour after sunset, Venus, over 25° up in the west-northwest, is over 7° to the right of the crescent moon (4d, 14%). The planet is 5.5° to the lower right of Beta Tauri. The moon is 5° to the lower right of Zeta Tauri, the southern horn of Taurus.

Venus is at the interval of greatest brightness on April 27. On this evening, the waxing crescent moon (5.0d, 22%) is over 17° to the upper left of Venus. The planet has an elongation of 40°, and it is midway between its greatest elongation and inferior conjunction. Venus is at its greatest illuminated extent.  The illuminated portion of the planet covers the largest area of the sky. (For a more technical explanation of greatest illuminated extent, see https://tinyurl.com/venus-greatest-illuminated.) Venus closes in on Beta Tauri.  The gaps: Apr 27, 5.1°; Apr 28, 4.6°; Apr 29, 4.1°; Apr 30, 3.7°.

A Venus – Beta Tauri Quasi-Conjunction and a Venus – Mercury Conjunction

2020: Venus approaches but it does not pass Beta Tauri, the northern horn of Taurus, for a quasi-conjunction (near conjunction).  Look for Venus and the star about 60 minutes after sunset in the west-northwest.

During May, Venus rapidly descends toward the western horizon, as measured from its setting time compared to the sun. Venus is nearing its quasi-conjunction (or near conjunction) with Beta Tauri.  The gap between the brilliant planet and the star: May 1, 3.3°; May 2, 2.9°; May 3, 2.6°; May 4, 2.3°; May 5, 2.1°; May 6, 1.9°; May 7, 1.7°; May 8, 1.6°, May 9, 1.5°.

On May 10, Venus is at its closest approach to Beta Tauri, a quasi-conjunction or “near conjunction.” One hour after sunset, Venus, over 17° up in the west-northwest, is 1.4° to the lower left of the star.

The next evening, May 11, Venus is 30° east of the sun. The Venus – Beta Tauri gap is still 1.4°, but slightly larger than last night, when the small fractions of a degree are included in the measurement.  The Venus – Beta Tauri gap begins to widen:  May 12, 1.5°; May 13, 1.6°; May 14, 1.7°; May 15, 1.8°; May 16, 2.0°; May 17, 2.2°; May 18, 2.4°.

On May 19, Venus sets at the end of evening twilight, nearly 2 hours after sunset. Forty-five minutes after sunset, Venus, 11° up in the west northwest, is 2.7° from Beta Tauri.  As this celestial pair descends toward the western horizon during the next several evenings, Mercury emerges from the sun’s glare for its evening apparition.  This evening. Venus is 4.8° to the upper left of Mercury (m = −0.8).  Watching Mercury’s rapid movement during the next several evenings, you will see it move from Venus’ lower right to its upper left.

Venus is moving very rapidly toward the sun.  On May 20, Venus  is 20° from the sun. The Venus – Beta Tauri gap is 3.0° and bright Mercury is 2.8° to the lower right of brilliant Venus.  During the next few evenings, the Venus- Beta Tauri gap continues to widen: May 21, 3.4°; May 22, 3.8°.

Mercury closes in on Venus.  On May 21, Venus, in the west-northwest, is 1.1° to the upper right of bright Mercury, a conjunction. The Venus – Beta Tauri gap is 3.4°.

2020, May 22: Look for brilliant Venus, Mercury and Beta Tauri 45 minutes after sunset in the west-northwest.

On May 22, Venus, Mercury, and Beta Tauri make a compact triangle. Venus is 1.6° to the lower right of Mercury; Venus is 3.8° below Beta Tauri; and the Mercury – Beta Tauri gap is 3.4°. Tomorrow evening the moon enters the scene.

2020, May 23: The crescent moon joins Venus, Mercury, and Beta Tauri, 45 minutes after sunset.

During the next evening, May 23, at 45 minutes after sunset, Venus, about 8° up in the west-northwest, is 4.7° to the upper right of the crescent moon (1.3d, 2%). The Venus – β Tauri gap is 4.2°. Mercury  is 3.6° to the upper left of Venus and 3.1° to the lower left of Beta Tauri.

2020, May 24: The crescent moon appears to the upper left of Venus, Mercury and Beta Tauri 45 minutes after sunset. Note the changing positions of Venus and Mercury compared to the star.

This spectacle is not, yet, finished. On May 24,  Venus, bright Mercury , Moon (2.3d, 5%), and Beta Tauri are near each other. The planets and the star make a triangle.  Mercury is 5.5° to the upper left of Venus, nearly midway from Venus to the moon that is nearly 12° to the upper left of Venus, although Mercury is above a line that connects Venus and the moon.  Betai is 4.6° above Venus and 3.5° to the upper right of Mercury. Venus’ elongation from the sun is 15°.

The next evening, May 25, 45 minutes after sunset, Venus is 4° up in the west-northwest. The planet continues to make a triangle with Mercury and Beta Tauri.  Venus is 5.1° to the lower right of the star, while Mercury is 4.5° to the upper left of Beta Tauri. Venus sets at Nautical Twilight, over an hour after sunset.  The observing window is rapidly closing to see Venus.  The gaps of the two planets and star continue to grow as Venus disappears into brighter twilight.

Venus is now quickly disappearing into bright twilight.  On May 28, 30 minutes after sunset, Venus is less than 3° up in the west-northwest. The planet is  only 9° from the sun, setting only 49 minutes after sunset.

By May 30, Venus sets at Civil Twilight, 32 minutes after sunset.  Good-bye, Venus, for this appearance!

2020: June 3: Venus passes between Earth and sun (Inferior Conjunction).

On June 3, Venus is at inferior conjunction, 12:44 p.m. CDT, when it is 0.5° north of the sun and 58” across.

This evening apparition of Venus has several exciting conjunctions with planets and stars. As with every evening appearance, Venus slowly moves into the sky.  As the evening ecliptic takes a more favorable angle as the weather warms and daylight grows, the planet reaches its latest setting time and greatest brightness as Spring arrives. At this time, it has a spectacular conjunction with the Pleiades and a near-conjunction with Beta Tauri before it seemingly dives between our planet and the sun to reappear in the morning sky.  Early during the next apparition,  Venus has a double conjunction with Aldebaran and a traverse through the Hyades in a fairly dark sky.   It also passes several bright stars near the ecliptic including Regulus and Spica.  Appearances of Venus with the moon provide broader views of the sky.  As noted in the daily descriptions, Venus has conjunctions with Saturn and Jupiter, but they occur during bright twilight.   When the Venusian cycle repeats its motions in eight years, Venus goes into the Pleiades appearing nearly between Merope and Alcyone.

2019, August: Mercury and Heliacal Rising of Sirius

The heliacal rising is the first appearance of a bright star in the morning sky before sunrise.

During August, as Mercury makes a morning appearance, brilliant Sirius, the sky’s brightest star, makes its first morning (heliacal) rising just before sunrise.  For the latitude on the diagram, about 41.7 degrees, this is August 14, 2019.  For locations farther south, this occurs days earlier and later for latitudes farther north.

August 29:  Now appearing in the darker morning sky, Sirius is visible with Betelgeuse and Procyon.

Sirius, the Dog Star, is sometimes called the Nile Star as its heliacal rising historically coincided with the flooding of the Nile River.  The Dog Days of Summer (in the northern hemisphere) occur, coincidentally, during August when Sirius and Procyon, the Little Dog Star, appear in the eastern sky before sunrise.

Update:  August 9, Mercury is low in the northeast.  First located with a binocular then observed without its assistance.

Mercury is at greatest elongation on August 9.  Because Mercury is closer to the sun than Earth, we see Mercury appear in either the morning or evening sky around the time the sun rises or sets.  It appears in the sky earlier each morning or stays there later each night.  It reaches its greatest separation from the sun and then seems to reverse its direction, moving back into sunlight, only to repeat the process a few months later at the other horizon and sky setting.

As Mercury moves back toward the sun in August, it is lower in the sky each morning at about the same time.  Sirius appears higher in the sky each morning at the same time.  And Mercury gets brighter as it appears nearer to the sun.  As Sirius appears higher, it seems to brighten because it gets above the thicker atmosphere that tends to diminish the brightness of celestial objects.  They are not quite the same brightness, but appear at the same altitude around August 19.

To locate the planet and the star, find a clear horizon in the east-northeast and east-southeast.  Start looking for Mercury and Sirius about 30 minutes before sunrise.  A binocular may help in viewing them.  Mercury is low in the east-northeast, about 10 degrees up.  Sirius is very low, in the east-southeast about 3 degrees up when first visible.  Sirius may twinkle wildly this low in the sky.  To be sure you have Sirius, don’t confuse it with Procyon in the east and a little higher.  Orion is higher in the sky and its three belt stars make an imaginary pointer that take us to the area to find Sirius.  Reddish Betelgeuse is higher in the sky,  Sirius, Procyon, and Betelgeuse make nearly an equilateral triangle known as the Winter Triangle.

Sirius’ heliacal rising occurs every year about this time.  This year the event is a little more interesting because a bright planet is in the sky.

2019, June 5-30: Mercury and Mars in the Evening Sky

The chart above shows the evening positions of Mercury and Mars from June 5, 2019, to June 30, 2019. The moon is part of the scene on June 5 and June 6.

About 45 minutes after sunset, Mercury and Mars are visible in the west-northwest  beneath Pollux and Castor, the Gemini Twins.  Early in the month, the  stars are about one-third of the way up in the sky.

Mercury is beginning an evening appearance.  Early in the month, it is brighter, but closer to the horizon.

Twilight lasts longer this time of year, so it’s not visible in the latter sky glow as the sky darkens further.  So, the upcoming conjunction with Mars is better viewed with a binocular.  Both planets’ movements are easier viewed across several nights.

On June 5, the waxing crescent moon, the waxing crescent moon that is 2.7 days past the New phase and only 9% illuminated is 6.3° to the upper left of Mars, which sets at the end of evening twilight.  At this time the Red Planet is about 13° up in the west-northwest, a little over halfway between Castor and Pollux and the horizon.

Each evening until the conjunction, Mercury is closer to Mars.

On June 18, Mercury passes close to Mars, less than the moon’s apparent diameter.  The chart above shows them 45 minutes after sunset when they appear in the west-northwest.  Use a binocular to locate them.  Can you see them without a binocular?

As the month progresses, the planets appear lower and in a brighter sky. Continue to use a binocular to track the planets.

By month’s end, a dimmer Mercury appears to the upper left of Mars.