2017, June: Jupiter in Evening Sky

Jupiter is the bright “star” in the southern sky during the early evening hours this month. On June 3, the waning gibbous moon appears about 2 degrees to the upper left of the giant planet.  Spica appears 11 degrees to the lower left of Jupiter.  The constellation Corvus the Crow is nearby.

Jupiter ends its retrograde motion on June 8th and begins to move eastward again as compared to the sidereal background.  It slowly appears to move toward Spica, passing on September 5.

For more information about sky watching events:

 

2017, May 11: Jupiter, Spica & Big Dipper

Jupiter shines in the southeastern sky during the early evening hours near the star Spica.  Jupiter is about 10 degrees to the upper left of the star and the planet is over 20 times brighter.  The giant planet continues to retrograde for about another month.  (For details see the link at the bottom of this posting.)  Through binoculars, up to four of Jupiter’s largest moons might be visible.  The constellation Corvus is nearby.  It consists of four stars that make an irregular box.

Meanwhile the Big Dipper is nearly overhead during the early evening hours of May.  Its famous double star, Mizar and Alcor are visible.

For more information about the planets see:

2017, May: Jupiter in Evening Sky

Jupiter is that bright star shining in the eastern sky after sunset, rising about 3 hours before sunset early in the month.  It is retrograding (appearing to move west compared to the starry background) into early next month.  (See our article below about Jupiter and Spica.)  On the evening of May 7, the waxing gibbous moon appears about 2.5 degrees from Jupiter with Spica about 10 degrees to the lower left of the giant planet.

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Jupiter on May 11, 2017.

For more information about the planets see:

2017, April: Jupiter Dominates Evening Sky

Jupiter is the brightest “star” in the evening sky. It is low in the eastern sky during the early evening hours. It is just passed opposition rising just before sunset.

For more information about the planets see:

2017, April 7: Jupiter at Opposition

Jupiter reaches opposition on April 7, 2017. The giant planet rises in the east at sunset. The chart above shows the planet with Spica and the constellation Corvus in the southeast about 100 minutes after sunset (the end of twilight).  Jupiter is 7 degrees from Spica.

At opposition our planet passes between the outer planet and the sun.  Jupiter and the sun are on opposite sides of Earth.  When the sun sets in the west, Jupiter rises in the east.  As our planet rotates, Jupiter appears higher in the east.  At midnight it is south, opposite the time when the sun is south:  noon.  Jupiter begins to descend in the western sky, setting in the west as the sun rises in the eastern sky.

At this opposition Jupiter is nearly 415 million miles away from us.  This planet has highly reflective clouds and appears as the fourth brightest object in the sky, after the sun, moon, and Venus.

On the evening of April 10, the nearly full moon appears 3 degrees to the lower left of Jupiter.

For more about the planets’ appearances, see other articles in this list:

2017, Late March: Jupiter in Evening

Bright Jupiter appears in the evening sky during early Spring.  It rises in the eastern sky about an hour after sunset during late March.  This giant planet reaches opposition, rising in the eastern sky at sunset, on April 7.  It appears in the sky all night, setting in the west as the sun rises in the east.

Jupiter appears near Spica, a bluish star about 5 degrees to its lower right.  Jupiter is appearing near Spica throughout the year until it disappears into sun’s brightness in October.

As Jupiter rises, the bright golden-orange star Arcturus appears farther to the left (north) in the eastern sky.  The pair is separated by about 30 degrees.

Jupiter is brightest among the three celestial sights.  It is 10 times brighter than Arcturus and nearly 25 times brighter than Spica.

For more information about current sky events, see these articles:

2017: Venus as a Morning Star

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Venus last appeared in the morning sky in 2015 and 2016, when it appeared with Mars and Jupiter.

Introduction

Brilliant Venus zips into the morning sky during April  2017 and dominates the morning sky until year’s end.   During this morning appearance, Venus makes close appearances with the star Regulus and the planets Jupiter and Mars.

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This chart shows the rising time of bright planets, the moon, and stars near the planets’ orbital plane (ecliptic) compared to sunrise as calculated from U.S. Naval Observatory data for Chicago, Illinois in the Central Time Zone.  Additionally, the times when Jupiter sets and Saturn sets are charted compared to sunrise.  On April 7, Jupiter is at opposition and it sets in the west at sunrise.  The time differences are also displayed for Civil Twilight, Nautical Twilight and Astronomical Twilight.  At Astronomical Twilight, the sky is as dark as it gets naturally.

The rising time of Venus is represented by the green line on the chart.  It enters the chart in mid-March, reaching its maximum rising time difference during the summer, and leaves the sky in early 2018.  Notice that during the summer months of this appearance of Venus, the brilliant planet rises well before the beginning of twilight.  It stands low in the eastern sky as the sky brightens.

As Venus appears earlier in the morning sky, Jupiter shines brightly in the western sky, until about May 20 when Jupiter sets as Venus rises. (Notice on the chart, Jupiter sets line crosses the Venus rises at May 20.)  After this date Jupiter sets before Venus rises.  Similarly, Saturn, while not as bright as Jupiter or Venus, reaches opposition on June 15, setting in the west as Venus rises in the eastern sky.  Venus appears in the eastern morning sky and Saturn appears in the western sky until about July 25 when Saturn sets as Venus rises.  After this date Saturn sets before Venus rises.

Later in the year, Venus appears near Regulus.  This occurs near the date when the rising lines of Regulus and Venus intersect.  The same occurs for Mars, Spica, and Jupiter.  As Venus moves back into bright sunlight later in the year, it appears near Mercury, Antares and Saturn, although they appear together during bright twilight and out of view for most observers.

Venus has a close conjunction with Mars on October 5, followed by a very close (Epoch) conjunction with Jupiter on November 13.

The moon passes Venus each month, as our nearest celestial neighbor moves through its celestial path.  Two dates (May 22 and July 20) are especially noteworthy when Venus and the moon appear about 3.5 degrees apart.

Inferior Conjunction

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Venus moves between Earth and Sun on March 25, 2017; this is known as inferior conjunction.  Since Venus has a shorter orbital path and faster speed, it quickly moves into the morning sky.  The red line on the chart shows the division between morning and evening.  The line pointing from the earth to the sun indicates noon.  So at inferior conjunction, Venus rises with the sun, appears in the south at noon, and sets in the west at sunset.

Venus does not appear in the sky at midnight at mid-northern latitudes.  That occurs when a planet is opposite the sun in the sky as seen from Earth.  On the chart notice that the midnight line does not point toward Venus.

As Venus reaches this inferior conjunction, it passes above the sun.  Because it is north, above the sun, it rises earlier than the sun.  On conjunction morning it rises about 40 minutes before the sun.  On the rising chart above, it first appears on the chart on March 14, 11 days before it reaches conjunction!

Venus was last at inferior conjunction on August 25, 2015, 589 days between inferior conjunctions.

Greatest Brightness

The planet rapidly moves into the morning sky, rising earlier each morning.  It is very close to our planet and sparkles in the morning sky.  The brightness is from the proximity of the planet to Earth, its highly reflective clouds and the phase of the planet.  (Yes, Venus shows phases when viewed through a telescope.)  At this time Venus is about 170 times the moon’s distance, relatively close compared to other planets.

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From April 15 through May 13, Venus appears brightest in our skies, with the mid-point on May 1, 2017.  This is shown with the GB (greatest brightness) designation on the rising chart above.

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Update:  This image is from the beginning of the period of peak brightness.  Venus rises during twilight during maximum brightness during this appearance.

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Venus continues to rise earlier each morning. On the morning of May 22, the crescent moon appears about 3.5 degrees from Venus.

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Update May 22:  Venus and the moon appear together.

Greatest Elongation

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Venus reaches its greatest angular separation (46 degrees) from the sun on June 3.  This is shown by the GE symbol (greatest elongation) on the rising chart above.  It rises about 2 hours before sun near the beginning of twilight.

Venus Dazzles Morning Sky

 Venus continues rising earlier as summer begins.

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On July 14, Venus moves past Aldebaran.  The closest approach is about 4 degrees.

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The Binocular View

More striking is the star cluster near Venus and Aldebaran: Hyades.  The Hyades cluster is about 2.5 times farther away than ruddy Aldebaran.  Through binoculars, Venus, Aldebaran and the jewel-like stars of the cluster sparkle against the black velvet of the  predawn sky. Several dozen stars can be seen.

To the unaided eye, the Hyades resemble a check mark or a letter “V” if Aldebaran is included.

Clusters, like the Hyades, are used to refine distance measuring techniques as well descriptions of the lives of stars.  These clusters are thought to form at approximately the same time.  Stars that burn their nuclear fuels faster convert into other stellar forms sooner, such as red giants and red super giants.  From these stellar models, the estimate of the sun’s total lifespan is about 10 billion years.

Over time these clusters break apart; the gravitational forces between the stars are not strong enough to keep the cluster together.  The stars go their own way in their orbital path around the galaxy.

Our sun was likely formed in such a cluster and is now a lone star since it has gone into its own orbit around the Milky Way galaxy.

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On the morning of July 20, the crescent moon again appears with Venus.  The pair is separated by about 3.5 degrees.

In early August Venus rises about 3 hours before sunrise and begins to rise later each morning as displayed on the rising chart.  For the rest of the year, it loses about 30 minutes each month.

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In late summer and early Autumn look for Venus and Sirius at the same time.  Both are about the same height (altitude) above the eastern horizon.  Venus stands in the east-northeast and Sirius appears in the southeast.  Only the sun and moon shine brighter than Venus and Sirius is the brightest star in the night sky. See this link to view the last time Venus and Sirius appeared together in the morning sky.

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Venus continues its rapid eastward movement as compared to the stars and descent toward the sun’s glow, passing about a half degree from Regulus on September 20.  This pair rises about 2 hours before sunrise.

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Over a month later, Venus passes Spica.  The gap is nearly 4 degrees.

Mars Conjunction

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The first planetary conjunction of this appearance is with Mars.  On the morning of October 5, Venus passes 0.2 degrees from the Red Planet.  The planets are close on a few mornings before and after the conjunction.

Venus-Jupiter Epoch Conjunction

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Another Epoch (close) Conjunction of Venus and Jupiter occurs before sunrise on November 13.  The distance is about .2 degrees.  This conjunction is visible during twilight as the pair rises about 70 minutes before the sun.

The next conjunction between the pair is November 24, 2019 with the next epoch conjunction on April 30, 2022.

Superior Conjunction

Venus continues its rapid descent into bright sunlight.  Conjunctions occur with Mercury, Antares and Saturn, but they occur in bright twilight, out of the view of most observers.

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On January 9, 2018 passes behind the sun at its superior conjunction and reappears in the evening sky.

Lunar Conjunctions

The moon appears with Venus on the following dates:

April 23: 8 degrees

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May 22: 3.5 degrees (See description in text)

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June 20: 7 degrees

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July 20: 3.5 degrees (See description in text)
August 19: 4.5 degrees
September 17: 6 degrees
October 18: 5.5 degrees

Other Images

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Venus on April 2, 2017

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Venus:  May 8, 2017 (Even visible from the brightest city lights)

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Venus:  July 21, 2017

Venus provides a dazzling view of planetary, stellar and conjunctions during its morning appearance in 2017.