Tag Archives: conjunction

2020, September 13: Bright Jupiter Begins to Close on Saturn

Jupiter and Saturn in Sagittarius, September 13, 2020
2020, September 13: Saturn is 8.1° to the left of Jupiter. In the starfield, Jupiter is 2.1° to the lower left of Pi Sagittarii (π Sgr) and 2.9° to the lower right of 50 Sagittarii (50 Sgr). Saturn is 1.7° to the lower left of 56 Sagittarii (56 Sgr).


Jupiter’s retrograde ends and the Giant Planet begins to close on Saturn for the Great Conjunction of 2020.

by Jeffrey L. Hunt

Bright Jupiter and Saturn are in the south as the sky darkens from early evening twilight.

Jupiter is now moving eastward compared to the starry background, while Saturn retrogrades – moves westward compared to the stars – until month’s end.

This evening Jupiter is to the lower left of Pi Sagittarii (π Sgr on the photo above) and to the lower right of 50 Sagittarii (50 Sgr). 

Saturn is 8.1° to the left of bright Jupiter.  It is 1.7° to the lower left of 56 Sagittarii (56 Sgr).

The gap between Jupiter and Saturn begins to close until the Great Conjunction of 2020, when Jupiter seems to pass very close to Saturn in the evening sky.  This is the closest conjunction since the Jupiter – Saturn conjunction of 1623.  Great Conjunctions occur every 19.6 years, but this is the closest for nearly 400 years.

Before Jupiter passes Saturn in our sky, Jupiter edges past Saturn as viewed on the solar system’s scale in what is known as a heliocentric conjunction.  This occurs on November 2.

Continue to look for Jupiter and Saturn each evening.  During the next several weeks, watch Jupiter close the gap to Saturn.

Here is a daily summary about the planets during September.

Recent Articles

Venus and Moon, September 14, 2020

2020, September 25: Morning Planets, Mars and Venus

Bright Mars and brilliant Venus put on an early morning display.

2020, November 2: Jupiter – Saturn Heliocentric Conjunction

A Jupiter-Saturn Heliocentric Conjunction, November 2, 2020
2020, November 2: Jupiter passes Saturn in a heliocentric conjunction, as viewed from outside the solar system.

As the Great Conjunction of Jupiter and Saturn nears, Jupiter passes Saturn if viewed from the sun.

by Jeffrey L. Hunt

As Jupiter edges closer to Saturn in the evening sky of Earth, Jupiter passes Saturn as viewed from outside the solar system on November 2, 2020.  This is known as a heliocentric conjunction.  The next one for these two planets is on December 7, 2040.

If we were on Jupiter on November 2, we would say that Saturn is at opposition.  Saturn is in the opposite direction in the sky from the sun.  If we were Saturnians, then we would say that Jupiter is at inferior conjunction, between Saturn and the sun. Notice on the chart above that Earth is not close to the line of the heliocentric conjunction.

From these two planets in alignment, a question may develop about more planets appearing in a line from the sun. Astronomer Jean Meeus (Mathematical Astronomy Morsels, pp. 186-191) addresses the question.  Without reciting his reasons, the answer: “Never!” The dynamics of fast – moving Mercury to slow-moving Pluto (Yes, Pluto is one of the “Classic Nine” planets.), there is never a moment when all nine are in a line stretching from the sun.  He further notes that it’s impossible for even three to be in a line.  Reasonably they can be within a 60° angle of each other, 50° if Pluto is not included.

Jupiter and Saturn in Sagittarius, November 2, 2020
2020, November 2: Jupiter is 5.0° to the lower right of Saturn, about one hour after sunset. Look toward the south-southwest.

In our sky, the planets are 5.0° apart.  They can be found in the south-southwest about an hour after sunset on November 2.  Saturn is to the upper left of bright Jupiter. The planets are in front of the stars of eastern Sagittarius.  The famous “Teapot” shape is to the lower right of the planets.

The Great Conjunction occurs December 21, 2020.

Continue to watch Jupiter and Saturn, as the Jovian Giant moves in and passes the Ringed Wonder as viewed from our observing spot on Earth.

Recent Articles

2020, August 15: Moon, Venus Morning View

Moon and Venus are  spectacular in morning sky!

by Jeffrey L. Hunt

The moon appears 3.4° to the upper left of Venus this morning among the stars of western Gemini.

This evening, locate Jupiter and Saturn in the southeastern sky after sunset.

The first sightings of Sirius by the unaided eye occur during the next few mornings about 45 minutes before sunrise.

Here is a daily summary about the planets during August.

Recent Articles

Full moon

2020, October 31: Rare Halloween Full Moon

A rare Halloween Full Moon, 76 years in the making, is visible across most of the planet in 2020. This could be called a “Blue Halloween Moon.”

2020, August 12: Jupiter, Saturn Evening Stars

 

Jupiter and Saturn, August 12, 2020
2020, August 12: Saturn is 8.1° to the lower left of the Giant Planet. In the starfield, Jupiter is 1.4° to the right of 50 Sagittarii (50 Sgr), while Saturn is 2.4° to the lower left of 56 Sagittarii (56 Sgr).

Bright Jupiter and Saturn shine from the southeastern sky after sunset during August 2020.

by Jeffrey L. Hunt

Bright Jupiter and Saturn shine from the southeastern sky during late evening twilight this evening. 

Saturn is 8.1° to the lower left of the Giant Planet. The gap between them continues to widen during the next month. In the starfield, Jupiter is 1.4° to the right of 50 Sagittarii (50 Sgr on the photo) and 2.9° to the lower left of Pi Sagittarii (π Sgr), while Saturn is 2.4° to the lower left of 56 Sagittarii (56 Sgr).

This planetary pair passed opposition last month and the planets continue to retrograde in eastern Sagittarius.

Retrograde motion is a illusion that occurs when our faster moving Earth catches up to the outer planets, passes them, and moves away.

Jupiter retrogrades until September 12, and Saturn ends its westward illusive apparent motion on September 28.

Then Jupiter approaches Saturn for a once-in-a-generation Great Conjunction on December 21, 2020.  This is the closest conjunction since 1623.

As the evening progresses, Mars appears in the eastern sky as the midnight hour approaches.

Venus is above the horizon by 3 a.m.  Tomorrow morning (August 13), Venus moves into Gemini.

Venus and the crescent moon make a beautiful grouping on August 15.  Get your camera ready!

The window is quickly closing to see the four brightest planets in the sky together.  Venus is moving eastward compared to the starry background, while Jupiter is moving westward. Venus rises as Jupiter sets on August 25. Saturn follows in early September.  If you’re an early riser, what is the last date you see all four together?  You’ll need clear horizons in the east-northeast and toward the southwest.

The first sightings of Sirius by the unaided eye occur this week about 45 minutes before sunrise.

Here is a daily summary about the planets during August.

Recent Articles

2020, August 11: Last Call, Four Morning Planets

 

2020, August: Last call for four morning planets.
2020, August 11: The four bright planets span the morning sky from the east-northeast horizon to the southwest skyline until August 25 when Jupiter sets as Venus rises. The moon is between Mars and Venus until August 15.

 

Venus, Mars, Saturn, and Jupiter are making their final appearance together during 2020.

by Jeffrey L. Hunt

For the next several mornings, Venus, Mars, Saturn, and Jupiter are visible in the sky together, spanning the celestial vault from the east-northeast horizon to the southwest skyline.  Locate a clear spot to view Venus and Jupiter simultaneously.

The chart above shows the sky at three hours before sunrise. The planets appear as overly bright stars.  Brilliant Venus is low in the east-northeast.  Mars is high in the southeast.  Bright Jupiter is low in the southwest, with Saturn to its upper left.   The moon appears in the with the planetary quartet until August 15.

Venus continues to step eastward in the stars of Orion until August 13 when it moves into the constellation Gemini.  Jupiter, at the western extreme of this morning planet parade, is retrograding in eastern Sagittarius.

The Venus – Jupiter gap continues to widen.  On August 25, the two planets are in opposite directions for us.  Jupiter sets as Venus rises, leaving three planets in the morning sky.  Saturn disappears below the southwestern horizon early next month, leaving Mars and Venus in the morning sky.

Venus in Orion, August 10, 2020
2020, August 10: Venus is 1.3° to the lower left of χ2 Ori and 2.8° to the lower right of Eta Geminorum (η Gem).

Venus and the crescent moon make a beautiful grouping on August 15.  Get your camera ready!

Mars in Pisces, August 9, 2020
2020, August 10: The moon is 12° to the left of Mars. The Red Planet is 2.4° to the upper left of 89 Piscium (89 Psc) and 1.6° to the lower right of Mu Piscium (μ Psc.)

Mars continues to march eastward in Pisces.  It is nearing a point where it appears to begin to retrograde.  The photo above shows the starfield where it appears for the next several weeks.  Mars appears to pass Mu Piscium (μ Psc on the photo) and move toward Nu Piscium (ν Psc).  Use a binocular to track Mars in the starfield.

The four planets are in the sky together for a short spell during early August 2021 as Mars disappears toward its solar conjunction in the west and Jupiter enters the evening sky, with Saturn and Venus between the two other planets.

Meanwhile, this year, Jupiter and Saturn are easy to spot in the southeast after sunset.  After the giant planet pair ends its retrograde next month, Jupiter approaches and passes Saturn on December 21, 2020 in a Great Conjunction, the closest since 1623.

On the morning of August 12, view the annual Perseid meteor shower.  While a brighter moon outshines the dimmer meteors, five or six meteors are visible each hour on the prime morning.

The first sightings of Sirius by the unaided eye occur this week about 45 minutes before sunrise.

Here is a daily summary about the planets during August.

Recent Articles

Venus and Jupiter, August 18, 2012

The Harvest Moon

The Harvest Moon is the full moon that occurs nearest to the autumnal equinox in the northern hemisphere.

2020, August 4: Jupiter, Saturn Bright Evening Stars

 

Jupiter and Saturn, August 4, 2020
2020, August 4: About 70 minutes after sunset, Jupiter is 0.8° to the lower right of 50 Sagittarii (50 Sgr) and 3.6° to the lower left of Pi Sagittarii (π Sgr). Meanwhile, Saturn is 2.8° to the lower left of 56 Sagittarii (56 Sgr).

Look for bright Jupiter and Saturn in the southeast during the hours following sunset.

by Jeffrey L. Hunt

Jupiter and Saturn are low in the southeastern sky during the hours following sunset. They appear as overly bright stars.  Jupiter is to the upper right of dimmer Saturn. This evening they are 7.8° apart.  The pair continues to retrograde in eastern Sagittarius as the gap between them grows. 

Retrograde is an illusion that appears when Earth overtakes, passes, and moves away from planets that revolve around the sun farther from our central star than our home planet.  Normally, planets appear to move eastward when compared to the starry background.  While they rise in the east and set in the west during a 24-hour period from Earth’s rotation, these planets seem to move eastward compared to the stars. This occurs because of the mutual revolution of Earth and the planets around the sun.

Earth passed Jupiter on July 13 and Saturn a week later.  This giant planet duo retrogrades until next month.  When they resume their eastward motion, Jupiter overtakes and passes Saturn on December 21, 2020 in what is known as a Great Conjunction.

Jupiter revolves around the sun in 11.8 years and Saturn in 29.5 years.  Jupiter overtakes and passes Saturn in our sky every 19.6 years.  While the great conjunction is not rare, it occurs at intervals of once every generation.  This year’s conjunction is the closest passing of the two planets since 1623.

Each night at the same hour Jupiter and Saturn are farther westward in the sky.  The December conjunction occurs in the southwest sky.

If you’re up early enough tomorrow morning, catch Jupiter and Saturn before they set at 4 a.m.  At that hour bright Mars is in the southeast and brilliant Venus is in the east.

Here is a daily summary about the planets during August.

2020, August 4: Four Morning Planets, Bright Moon

Venus, Mars, Saturn, and Jupiter shine from the morning sky.  The morning planet parade breaks apart.

by Jeffrey L. Hunt

About two hours before sunrise, brilliant Venus gleams from the eastern sky.  It is near the Southern Horn of Taurus the Bull, known as Zeta Tauri (ζ Tau on the photo). 

For over a month, Venus has been moving eastward in Taurus.  Tomorrow, Venus moves into the club region of Orion.  Bellatrix, a shoulder of Orion, is visible in the photo above.

Mars in Pisces, August 4, 2020
2020, August 4: Shining from the dim stars of Pisces, Mars is is 0.3° to the upper left of 89 Piscium (89 Psc on the photo) and 3.7° to the lower right of Zeta Piscium (ζ Psc).

About an hour earlier, with a bright moon in the sky and only four hours past its official Full phase, Mars shines from the dim starfield of Pisces. It continues to march eastward along the solar system’s plane.  Use a binocular to track Mars through the starfield, especially with the bright moon in the sky for the next several mornings.

Next month, the Red Planet starts to retrograde.  Mars appears to move westward compared to the stars.  On October 13, 2020, Earth passes between the planet and the sun.  Mars and the sun are in opposite directions from Earth.  This is known as opposition.  The planet rises in the east at sunset and sets in the west at sunrise.  Around opposition, Mars is closest to Earth and appears at its brightest.  This occurs a week before opposition.

This morning Mars is 0.3° to the upper left of 89 Piscium (89 Psc on the photo) and 3.7° to the lower right of Zeta Piscium (ζ Psc).

Jupiter and Saturn, August 4, 2020
2020, August 4: Appearing low in the southwest, Jupiter and Saturn are disappearing from the early morning sky. This morning, Saturn is 7.8° to the upper left of Jupiter.

Jupiter and Saturn are appearing very low in the sky at this hour.  Better views occur when the planets are in the evening sky.  Ninety minutes after sunset, they are shining from low in the southeastern sky,

Both planets are retrograding in eastern Sagittarius.  They reverse their courses next month.  As the year closes, Jupiter passes Saturn on December 21, 2020, in a Great Conjunction.

Here is a daily summary about the planets during August.

 

2020, July 28: Jupiter and Saturn Lead July’s Morning Planet Parade

Jupiter and Saturn, July 28, 2020
2020, July 28: Jupiter is 0.6° to the left of 50 Sagittarii (50 Sgr), while Saturn is 3.3° to the upper left of 56 Sagittarii (56 Sgr).

Jupiter and Saturn lead Mars and Venus during late July’s morning planet parade.

by Jeffrey L. Hunt

Four planets – Jupiter, Saturn, Mars, and Venus – are strung along an arc in the morning sky.  They appear along the solar system’s plane that astronomers call the ecliptic. During the pre-sunrise hours of late July, the imaginary line stretches from the southwest skyline to the east-northeast horizon.

Bright Jupiter and Saturn are low in the southwest in front of the stars of eastern Sagittarius.  They are moving westward – retrograding – compared to the starry background.  While they rise in the east before sunset and appear low in the southeast during evening hours from Earth’s rotation, they are moving westward compared to the distant stars.  This westward movement compared to the stars is an illusion when Earth overtakes, passes, and moves away from them.

Jupiter and Saturn are 7.5° apart.  In another month, they are about another degree apart. 

In September, Jupiter and Saturn begin moving eastward again.  Jupiter inches toward Saturn and passes it in a Great Conjunction, December 21, 2020.  This is the closest conjunction of the two planets since 1623.  A Jupiter – Saturn conjunction occurs every 19.6 years.

Through a binocular check their positions each clear morning compared to the stars.  Jupiter is 0.6° to the left of 50 Sagittarii (50 Sgr), while Saturn is 3.3° to the upper left of 56 Sagittarii (56 Sgr).  Watch Jupiter pass 50 Sgr and Saturn approach 56 Sgr.

Mars in Pisces, July 28, 2020
2020, July 28: Mars is 5.1° to the upper left of 20 Ceti (20 Cet) and 5.0° below Epsilon Piscium (ε Psc).

Farther east, Mars is that “bright star” in the southeast.  It is among the dim stars of Pisces.  On the photo above, it is moving into the starfield where it retrogrades and passes opposition (October 13, 2020).  This morning the Red Planet is 5.1° to the upper left of 20 Ceti (20 Cet) and 5.0° below Epsilon Piscium (ε Psc).  As with Jupiter and Saturn, watch Mars move eastward in the starfield through a binocular.

Venus in Taurus, July 28, 2020
2020, July 28: Venus, in the constellation Taurus, is 4.3° to the upper right of Zeta Tauri (ζ Tau), the Southern Horn of the Bull.

The brilliant Morning Star Venus is in the eastern sky.  It is moving eastward among the stars of Taurus.  This morning it is 4.3° to the upper right of Zeta Tauri (ζ Tau), the Southern Horn of the Bull.  The bright star Aldebaran, the Bull’s Eye, and two star clusters (Hyades and Pleiades) appear above the bright planet.

Here are two daily summaries about the planets during July and August.

2020, July 26: A Morning Planetary Quartet

Jupiter and Saturn. July 26, 2020
2020, July 26: Bright Jupiter and Saturn are in the southwest during morning hours, they are 7.3° apart. Jupiter is 0.7° to the left of 50 Sagittarii (50 Sgr). Saturn is 3.4° to the upper left of 56 Sagittarii (56 Sgr). Jupiter’s moon Ganymede is visible.

Four bright morning planets – Venus, Mars, Saturn, and Jupiter – span the sky.

by Jeffrey L. Hunt

Four bright planets – Venus, Mars, Saturn, and Jupiter – span the morning sky from the east-northeast horizon to the southwest skyline.

During the predawn hours, bright Jupiter and Saturn are in the southwest.  They appear among the stars of eastern Sagittarius. These giant planets are 7.3° apart.  Look at Jupiter with a binocular.  It’s possible to see some of its four bright Galilean moons, first observed in Galileo’s telescope during the 17th century.  This morning Ganymede is visible in the photo above.

Jupiter passes Saturn in a Great Conjunction on December 21, 2020.

Look for Jupiter and Saturn in the southeast about an hour after sunset, as they clear the local trees, houses, and buildings.  During the night, they appear to move westward.

Mars is Cetus, July 26, 2020.
2020, July 26: Mars, high in the southeast, is 4.3° to the upper left of 20 Ceti (20 Cet) and 5.3° to the lower right of Epsilon Piscium (ε Psc).

During the morning hours, Mars is high in the southeast, among the stars of Cetus.  Tomorrow it moves into Pisces.  The stars identified on the accompanying photo show the dim star field where the Red Planet passes opposition, October 13, 2020.

Venus in east, July 26, 2020.
2020, July 26: In Taurus, brilliant Venus is morning eastward toward Zeta Tauri (ζ Tau). This morning Venus is 5.8° to the upper right of the star.

Brilliant Venus is in the eastern sky.  It is in front of the stars of Taurus the Bull.  Watch it move toward and pass Zeta Tauri (ζ Tau), the Southern Horn of the Bull, on the photo, during the next several mornings.  This morning Venus is 5.8° to the upper right of the star.

Notice that Aldebaran and the Hyades star cluster make a sideways “V” that represents the head of the Bull.  The Pleiades star cluster is higher in the sky, and is said to be riding on the Bull’s back.

Here are more about the planets during July and August.

2020, July 24: Jupiter, Saturn, Mars, Morning Planetary Motion

Jupiter and Saturn in Sagittarius, July 24, 2020
2020, July 24: Bright Jupiter and Saturn appear in the southwest in the hours before bright morning twilight brightens the sky. This morning Jupiter is 0.9° to the left of the star 50 Sagittarii (50 Sgr on the photo above) and 4.8° to the upper left of Pi Sagittarii (π Sgr). Saturn is 3.5° to the upper left of 56 Sgr and 4.6° to the lower right of σ Cap.

Three bright planets – Jupiter, Mars, and Saturn – shine from the southern skies during the overnight hours.

by Jeffrey L. Hunt

Jupiter and Saturn rise into the southeastern sky as the sky darkens each evening.  Mars rises before midnight, and it is higher in the sky after midnight.

By 3 a.m. Jupiter and Saturn are in the southwest and Mars is high in the southeast.

Bright Jupiter and Saturn are near each other, 7.3° apart.  In the photo above, Jupiter and Saturn are in eastern Sagittarius.  The stars of the distant constellation form the backdrop for the moving planets.

Normally, the planets move eastward compared to the starry background.  About each year, our faster moving planet approaches Jupiter and Saturn. These planets appear to stop moving eastward and begin to move westward compared to the stars.  This is known as retrograde motion.  Earth then passes between Jupiter and the sun, then Saturn and the sun.  This is known as opposition.  As Earth moves away the planets continue to appear to move backwards, then they start their forward motion again.

For now, Jupiter and Saturn are retrograding, and Jupiter is getting farther from Saturn.  By the end of August, Jupiter is about 1° farther away from Saturn than it is this morning.  One degree is about the apparent size of two full moons.

Jupiter’s retrograde ends September 12. Even as Jupiter resumes its eastward motion, Saturn continues to retrograde.  Saturn’s retrograde ends September 28.  Jupiter then closes in on Saturn for a Great Conjunction, December 21, 2020.

Use a binocular to watch the planets move against the stars. This morning Jupiter is 0.9° to the left of the star 50 Sagittarii (50 Sgr on the photo above) and 4.8° to the upper left of Pi Sagittarii (π Sgr).  Observe that Jupiter passes 50 Sgr and moves closer to π Sgr during the next month.

Meanwhile, Saturn’s retrograde puts it 3.5° to the upper left of 56 Sagittarii (56 Sgr) and 4.6° to the lower right of Sigma Capricorni (σ Cap).  The Ringed Wonder appears to move closer to 56 Sgr and farther from σ Cap during the next month.

Mars in Cetus, July 24, 2020
2020, July: Bright Mars in the southeast among the stars of Cetus near the Pisces-Cetus border. This morning Mars is 5.6° to the lower right of ε Psc, and 3.6° to the upper left of 20 Cet.

Farther east, Mars is marching eastward, over halfway up in the southeast at this hour.  The Red Planet is in front of the stars of Cetus.  In three mornings, it moves back into Pisces.

About every two years, Earth approaches and passes between the sun and Mars.  This year opposition occurs on October 13, 2020. Mars begins to retrograde on September 9, 2020.  The planet is moving eastward, but its eastward progress slows in about three weeks.

Mars is well passed 20 Ceti (20 Cet on the photo) and heading toward a starfield in Pisces that includes Zeta Piscium (ζ Psc on the photo), 89 Piscium (89 Psc), Mu Piscium (μ Psc), Nu Piscium (ν Psc), and Omicron Piscium (ο Psc).  Including Epsilon Piscium (ε Psc) and Delta Piscium (δ Psc), Mars’ motion during the next month is within the dim starfield displayed on the photo.

This morning Mars is 5.6° to the lower right of ε Psc, and 3.6° to the upper left of 20 Cet.  Each clear morning, observe Mars’ place among the stars with binocular.

Here’s more about the planets during July.