2018: Venus the Evening Star


 

Update:  July 9, 2018

Photograph of Venus and the moon during twilight on September 3, 2016 -- the most recent evening apparition of Venus.

Figure 1: Venus appears in the evening sky during its 2016 evening appearance.

This article has many details about the appearance of Venus in the evening sky during 2018.  Bookmark it so that you can return to check the details.  Stop back, we’ll update this page with photos throughout the article and display a collection of them at the end.

Venus shines brightly as an Evening Star for most of 2018. It appears in the western sky as the three bright outer planets dance in their retrograde loops throughout spring and summer. 

These articles outline the planetary activity during 2018:

Unless noted, the charts in this article are computed for Chicago, Illinois, in the U.S.A. Central Time Zone (CST, -6 hours).  Daylight Saving Time (CDT, -5 hours) is shown when that occurs.

Figure 2: The chart shows the setting time of Venus compared to sunset, along with the setting time differences of other bright planets, stars and the moon (circles).  The boxes indicate conjunctions with other stars and planets.  The yellow triangle with the letters “GE” indicates Venus’ greatest elongation.  The greatest brightness is marked with the yellow diamond and the letters “GB.”

Introduction

The setting chart above shows the setting of Venus and other planets, bright stars, and the moon (circles) compared to sunset.  The white boxes indicate Venus conjunctions with other planets and stars.  After its solar superior conjunction in early January, Venus slowly moves into the evening sky.  Two months pass before it sets an hour after sunset, shining brightly in the western sky after sunset.  With the lengthening twilight that occurs at mid-northern latitudes (the chart is graphed from data for Chicago, Illinois), Venus reaches its latest setting time after sunset (2 hours, 40 minutes) in late May.  It appears low in the western sky after the end of twilight from March 28 through July 24 (for this latitude).  Meanwhile it passes through the stars of Taurus with a conjunction with Aldebaran, then Pollux, and finally Regulus during the evenings when it sets after twilight.  Because of the low inclination of the ecliptic it reaches greatest elongation and its duration of greatest brightness when it sets during evening twilight.  This article provides more detail about these events during the early evening hours of 2018.

Superior Conjunction Starts the Evening Apparition

Figure 3: The evening appearance of Venus begins when the planet passes superior conjunction when Venus is on the far side of the sun. At this time it is in the sky during the day and in the south at noon. The noon line on the chart points through Venus, indicating its direction and time.

The Venus apparition begins on January 9, 2018 (1:02 a.m. CST) when it passes superior conjunction. We cannot see Venus as it is on the far side of the sun and is in the sky with the sun. It rises in the east at sunrise, is in the south at noon, and sets in the west at sunset.

After its solar conjunction, Venus climbs slowly in the western evening sky. A month after conjunction it sets about 35 minutes after sunset, setting about 10 minutes later each week.

The chart above (Figure 2) shows the setting times of Venus, other bright stars, and planets compared to Sunset. Moon set is shown by the circles. We should note that these are setting times when Venus and the other celestial objects cross the natural horizon, leaving the sky.  Look for them between sunset and their setting time intervals. By mid-February, Venus appears low in the Southwest after sunset.

The author’s first view:  February 25, 2018

While it is the brightest “star” in our sky, it continues to grow in brightness as it slowly catches our planet.  For Venus, Earth is an outer planet, like Mars is for Earth.  Moving on a shorter orbit and at a faster speed — Venus revolves around the sun every 225 days, yet successive solar conjunctions (inferior-inferior or superior-superior) occur every 584 days. These configurations are named from Venus’ position compared to Earth.

Mercury Conjunction, March 3

 

Update: On March 3, Mercury passes about 1 degree from Venus as both planets emerge from their superior conjunctions.

Venus and Mercury, March 3, 2018

Update:  This conjunction has been added to the original article — As Venus and Mercury emerge from superior conjunction Mercury passes about one degree from Venus on March 3.  The planets are low in the western sky, about 5 degrees above the horizon at 30 minutes after sunset.  Venus is 5 times brighter than Mercury.  It may be necessary to first locate Mercury with binoculars. 

Mercury Conjunction, March 18

Figure 4: The first conjunction of this appearance of Venus is with Mercury on March 18, 2018 during evening twilight.

 

Venus, Mercury and the crescent moon,: March 18, 2018

Update:  March 18, 2018

By March 1 Venus continues to set later, now about 100 minutes after sunset. It still sets before the end of twilight . On March 18, Mercury passes about 4° from Venus with the moon nearby. By the end of March (March 28), Venus now sets after twilight ends.  It rapidly moves eastward compared to the background stars.

Venus in Taurus

Figure 5: During late April , Venus moves among the stars of Taurus. On April 24, Venus moves past the Pleiades star cluster. They are about 3.5 degrees apart. Look at the region with binoculars to see the region’s star clusters.

By late April, Venus moves through the stellar background of Taurus with its two bright star clusters:  Pleiades and Hyades.  The Pleiades is a compact grouping of bright bluish stars known to school children as “The Seven Sisters.”  The cluster resembles a tiny dipper.  To the unaided eye, 6 or 7 stars are visible.  A dozen or so through binoculars.  A few hundred through telescopes.  The Hyades are nearby.  This group resembles a check mark, a letter “V” when Aldebaran is included, although it is not part of the cluster.

Astronomical theory describes that stars are formed in bunches from a stellar, gaseous nebula.  Over time the mutual gravitation pull of the stars within the cluster is not strong enough to keep the group together.  The Hyades and Pleaides are close enough (within 400 light years) that they can be seen without a telescope.  Many star clusters are just beyond the perception of our eyes.  Binoculars help reveal them.  If you’re interest in star clusters is piqued, start here.

Figure 6: Venus passes 6.5 degrees from Aldebaran on May 2. With binoculars look at this region every clear night while Venus is there.

During the next week, Venus moves between the Hyades and the Pleiades, passing 6.5 degrees from Aldebaran on May 2.  Venus and the surrounding stars are less than 15 degrees above the west-northwest horizon.  Look at this region with binoculars every clear night.

Figure 7: Venus moves between the horns of Taurus (Zeta Tauri and Elnath during mid-May. It passes within 4 degrees of Elnath on May 13 and about 3.5 degrees from Zeta Tauri the next evening.

Venus and Moon

The moon passes Venus during its monthly succession of phases.  On the setting chart (Figure 2) above, note that the moon and Venus set at nearly the same time on several days.  We chose three of those dates to feature here.  In the charts in this section (Figure 7, Figure 8, and Figure 9)  the moon appears near Venus.  Here are some of the details:

  • May 17, 2018:  Venus and the moon are 6.2 degrees apart at chart time (9:15 p.m. CDT).  They are 14 degrees above the west-northwest horizon.  The moon is only 2.5 days old.  This region of the sky is full of bright stars; Capella is shown on this chart.  To keep the scale of the three charts the same, the view is limited.
  • July 15, 2018:  The nearly 3-day-old moon is slightly less than 2 degrees from Venus.  (The moon is over sized on this charts.)  The star Regulus is 6.75 degrees to the lower right of Venus.  (There is a conjunction with Regulus on July 9.  See the text for more details.)
  • August 13, 2018:  The moon is 2.5 days old and appears 10 degrees to the right of Venus.

Venus & Pollux

Figure 11: Venus passes the Gemini Twin Pollux on June 7.

After its conjunction with Aldebaran, Venus continues its eastward movement against the stars as it moves into Gemini, reaching Pollux in early June.  It passes 4.75 degrees from Pollux on June 7.  The trio of stars that includes Castor is about 15 degrees above the west-northwest horizon.

Venus and the Beehive

Figure 12: Venus passes the Beehive star cluster on June 19. It is dimmer than the star clusters in Taurus.

After Venus moves through Gemini, it moves into a region with inconspicuous stars known as Cancer.  The Beehive star cluster is in this star field.

Observers with sharp eyesight and a darker sky can see the cluster without binoculars.  For them it appears as a cloudy patch nearly halfway from Pollux to Regulus.

With binoculars stars are visible in the cluster.

The cluster is farther away (500 light years) and consequently dimmer than the Hyades or Pleiades.  Point your binoculars at Venus on June 19 at 9:30 p.m. CDT, the Beehive cluster is immediately to the left of the brilliant planet.

Venus Meets Regulus

Figure 13: Venus passes within 1 degree of Regulus on the evening of July 9.

Venus continues moving eastward along the ecliptic through the stars of Cancer toward Leo.  In early July, Venus passes the next signpost of the ecliptic, Regulus.  This vivid blue star is less than one degree from Venus on July 9.  On the chart above (Figure 13), the pair is 12 degrees above the western horizon at chart time.

See Five Planets

During late July, observers at more southerly latitudes can see five planets at once.  This will be difficult for observers at mid-northern latitudes.  See the details in this article.

During the time when the five planets are visible, Venus starts setting before the end of twilight on July 24 (at Chicago’s latitude).

Greatest Elongation — East of the Sun

Figure 14: Venus reaches its greatest angular separation from the sun on August 17 when it is 46 degrees from the sun.

Venus is now rapidly catching our planet and growing in brightness.  It continues to move eastward from Regulus and the stars of Leo toward Spica.  On August 17, Venus appears farthest from the sun, known as the greatest elongation (angle).  Venus is about half the distance it was at the Mercury conjunction (March 18) and over 50% brighter.  It is now setting about 100 minutes after sunset and its setting time compared to the sun is decreasing about 5 minutes earlier each week.  This is displayed with the yellow triangle and the letters “GE” on the setting chart (Figure 2).  The result is that Venus is lower in the sky each night at the same time interval after sunset.

Venus is now 70 days before inferior conjunction.  It continues to catch Earth and brighten in the sky.

Venus Passes Spica

Figure 15: Venus passes 1.25 degrees from Spica on August 31. Venus appears lower in the sky as it heads toward inferior conjunction.

Two weeks after its greatest elongation, Venus passes 1.25 degrees from Spica. After the conjunction, Venus and Spica continue to set at about the same time — growing in separation — until they disappear into the sun’s glare in October.  Venus sets farther left (south) along the horizon.

Greatest Brightness

Figure 16: Venus reaches its greatest brightness on September 21st.

About September 16 and for the next two weeks, Venus enters its phase of greatest brightness.  The midpoint is September 21st.  This date is displayed with a yellow diamond and labelled “GB” on the setting chart (Figure 2).

Jupiter, But no Conjunction

Figure 17: On September 28, Jupiter closes with 14 degrees of Venus. There is no conjunction during this Venus apparition.

After its opposition, Jupiter appears farther west each night.  During late summer Jupiter sets 80 minutes after sunset and it appears that Venus and Jupiter are headed toward a conjunction.  After the Spica conjunction, Venus rapidly dives toward the sun’s glare as it moves toward its inferior conjunction with the sun.  The closest Jupiter gets is 14 degrees on September 28, setting about 70 minutes after Venus.  See the setting chart (Figure 2) to note the similar setting times of Venus and Spica and the minimum separation of Venus and Jupiter.

Inferior Conjunction Ends the Apparition

Figure 18: Venus overtakes and passes Earth on October 26, moving between our planet and the sun.

During October, Venus rapidly disappears into the sun’s glare and moves between Earth and the sun (inferior conjunction) on October 26 (9:16 a.m. CDT). This completes the evening apparition for Venus during 2018.

After its solar conjunction, Venus quickly moves into the morning sky. By Nov 8 it already rises at the beginning of twilight, gleaming in the eastern morning sky.

Summary

During 2018, Venus appears in the western evening sky.  It passes Mercury, Aldebaran, Pollux, Regulus, and Spica.  While its latest setting time is 160 minutes after sunset, its sets mostly during evening twilight during this appearance.  Late in the apparition, what looks like, an impending Jupiter conjunction never occurs.  There are several opportunities to view Venus and the moon.  Here we highlighted the close passings on May 17, July 15 and August 13.  Venus also passes the star clusters Pleiades, Hyades, and Beehive.  Binoculars help spot the clusters with brilliant Venus nearby.  Happy observing!

With the Moon

The moon is close to Venus on these dates (One degree is the size two full moons appear to our eyes without a telescope:

  • February 16 – 2.5 degrees (d)
  • March 18 – 4d
  • April 17 – 5.5d
  • May 17 – 6.2d
  • June 15 (7.5d) & 16 – 7.3d
  • July 15 – 2.2
  • August 13 – 10.5d
  • September 12 – 9d
  • October 11 – 3.1d

Photos

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