Category: Astronomy

Astronomy, Sky Watching

2020, August: Mars in Pisces, at Perihelion
Mars from Hubble during 2018
NASA’s Hubble Space Telescope photographed Mars on July 18, 2018, during a dust storm and near its closest approach to Earth since 2003. (NASA photo)

Mars marches eastward among the dim stars of southeastern Pisces during August. It passes perihelion early in the month.

by Jeffrey L. Hunt

Mars is approaching opposition on October 13, 2020.  At opposition Mars and the sun are in opposite directions in the sky. As the sun sets in the west, Mars rises in the east.  Mars appears in the south around midnight (1 a.m. during daylight time).  As morning twilight begins, Mars is low in the western sky, setting before sunrise.

In the sky, Mars appears as an overly-bright star.  It is the brightest star in this region of the sky, making its identification easy.

During early August, Mars rises at around 11 p.m., appearing low in the east as midnight approaches. At this time, Jupiter and Saturn are in the south.  This giant planet duo starts the evening low in the southeast as the sky darkens.

By early morning, about three hours before sunrise, Mars is part of a quartet of four bright planets that are stretched across the sky from the east to the southwest skyline.  Bright Venus is in the east, Mars in the south-southeast, and Saturn and Jupiter in the southwest.

 By midmonth, Mars rises about 30 minutes earlier and shines from higher in the eastern sky as midnight approaches. It continues to follow Jupiter and Saturn through the sky.

At this point that the planetary quartet begins to break up.  Jupiter disappears below the southwest horizon as Venus climbs into the eastern sky.

By late in the month, when Mars rises around 9:30 p.m. and is well-up in the eastern sky by 11 p.m. By early morning, Jupiter and Saturn have left the sky, as Venus climbs into view.

Mars in Pisces, August 2020.
August 2020: This chart shows the motion of Mars compared to the dimmer stars in southeastern Pisces. During the month, Mars passes near 89 Piscium (89 Psc, m = 5.1), Mu Piscium (μ Psc, m = 4.8), Nu Piscium (ν Psc, m = 4.4) and Omicron Piscium (ο Psc, m = 4.2).

Note that on the accompanying chart, the daily positions of Mars are farther apart than at the end of the month.  The planet begins to retrograde next month.  Before it reverses course and seems to move westward among the stars, it slows. (A chart in this article shows the retrograde pattern of Mars for this opposition.)  The gaps between the daily positions decrease in distance. At the beginning of the month, Mars moves eastward about 0.4° each day.  That’s a little less than the apparent size of the moon in the sky.  By month’s end, the Red Planet appears to move about half that distance each day.

Because Mars’ orbit is not a perfect circle, Mars is not necessarily closest to the sun or closest to Earth at opposition.  Mars is closest to the sun (perihelion) on August 2.  Our planet is closest to the Red Planet on October 6, followed by opposition a week later.

Use a binocular to track Mars’ eastward motion in the starfield.  Here are dates to note:

  • August 1: Mars starts the month 1.2° to the upper right of 89 Piscium (89 Psc).
  • August 2: Mars is closest to the sun (perihelion), 1.38 Astronomical Units from the sun. (An Astronomical Unit – AU – is equal to Earth’s average distance from the sun, about 93 million miles or 150 million kilometers).  At this time the Earth – Mars gap is still 0.63 AU.  Mars continues to brighten in our sky as we get closer to it.
  • August 4: Mars passes 0.3° above 89 Psc.
Mars and Moon, August 8, 2020
As midnight approaches the moon is 2.1° to the lower right of Mars that is about 13° in altitude in the east.
  • August 8: Before midnight, look eastward for Mars, 2.1° to the upper left of the gibbous moon that is 73% illuminated.  They’ll still be together in the morning.
  • August 14: The planet is 1.0° to the lower left of Mu Piscium (μ Psc).
  • August 22: Mars passes 0.5° below Nu Piscium (ν Psc).
  • August 31: Mars ends the month 2.7° to the lower right of Omicron Piscium (ο Psc).

For more about where to locate the planets in August, here is a semi-technical description of their locations for each day.

 

Astronomy, Sky Watching

2020, August: Jupiter, Saturn in Evening Sky
Jupiter Close up from Hubble Space Telescope
This Hubble Space Telescope view of Jupiter, taken on June 27, 2019, reveals the giant planet’s trademark Great Red Spot, and a more intense color palette in the clouds swirling in Jupiter’s turbulent atmosphere than seen in previous years. The colors, and their changes, provide important clues to ongoing processes in Jupiter’s atmosphere. (NASA Photo)

Jupiter and Saturn shine from the evening sky.  Catch a last glimpse of the morning planet parade with Venus, Mars, Jupiter, and Saturn.

by Jeffrey L. Hunt

Now past their opposition points, Jupiter and Saturn shine from the southeast after sunset.  In the early evening sky, bright Jupiter is to the upper right of Saturn.  During the night, the planetary pair appear farther eastward.

Aim your binocular or small telescope at these planets.  Usually, at least one of the four largest moons is visible near the planet.  With a telescope, Jupiter’s subtle atmospheric bands can be seen.  With Saturn, a hint of a ring might be visible with a binocular, that is easily viewed with a telescope.

Mars follows Jupiter and Saturn later in the evening.  Venus appears during the early morning hours.  The four planets parade across the early morning sky.  Jupiter sets after 4 a.m. CDT on August 1.  By month’s end, Jupiter sets a few minutes past 2 a.m. CDT. 

Viewing the four planets together becomes more difficult as the month progresses.  On August 25, our planet passes between Venus and Jupiter, a so-called Venus – Jupiter opposition.  The planets are on opposite sides of our planet – Venus rises as Jupiter sets.  This is not an observable event, but worth noting to explain the break-up of the morning planet parade.

Early in the month, bright Mercury is low in the east-southeast during morning twilight, but long after Jupiter and Saturn leave the sky in the southwest.

Jupiter and Saturn in the starfield, August 2020.
Jupiter and Saturn retrograde in eastern Sagittarius during August 2020. The motion is described in the daily notes. The stars that make the background of their motion is 56 Sagittarii (56 Sgr, m = 4.8), 50 Sagittarii (50 Sgr, m =5.6), and Pi Sagittarii (π Sgr, m =2.9). The planets are plotted at the end of twilight on August 15, 2020.

In the starfield, Jupiter and Saturn are retrograding – moving westward compared to the stars.  This is an illusion from our faster moving Earth approaching them, passing between Jupiter and Saturn and the sun, and then moving away from them.  Jupiter retrogrades until September 12.  It then resumes its eastward trek toward Saturn.  Saturn’s retrograde ends September 28.  Jupiter overtakes and passes Saturn on December 21, 2020.

A conjunction of Jupiter and Saturn occurs once every 19.6 years.  While not a rare event, the grouping of the two planets is of special note and referred to as a Great Conjunction.

During August, use a binocular to watch Jupiter and Saturn retrograde compared to the dimmer starry background.  The star designations – 50 Sagittarii, 56 Sagittarii, and Pi Sagittarii – certainly are not household names, but frequent looks at the starry background reveals the westward motion of Jupiter and Saturn. Now that the planets are higher in the evening sky, our daily detailed notes should help with tracking the five bright planets.

As the planets retrograde during August, the gap from Jupiter to Saturn widens about the apparent size of the full moon.  This is noticeable without a telescope.  The unaided eye can spot that difference with frequent sightings of the pair.

On the chart above, the four stars are indicated along with the locations of Jupiter and Saturn on August 15.  Before and after the planets are near these points, and certainly can be found with a binocular.

The moon is in the region of these planets during four nights.

 

August 1: In the evening sky, the bright moon is 2.9° below Jupiter and 6.7° to the right of Saturn. The giant outer planet pair is 7.7° apart.

On the evening of August 1, the bright moon is 2.9° below Jupiter and 6.7° to the right of Saturn.

Jupiter, Saturn, Moon, August 2, 2020
August 2: In the evening sky, the bright moon is in the southeast. It is 7.8° to the lower left of Saturn. The Ringed Wonder is 7.7° to the lower left of Jupiter.

On August 2, the gibbous moon is 7.8° to the lower left of Saturn as the evening sky darkens.

Jupiter, Saturn, Moon, August 28, 2020
August 28: In the evening sky, Jupiter is 2.2° above the moon. Saturn, 8.3° to the left of Jupiter, is 8.8° to the upper left of the moon.

The moon returns at month’s end.  On August 28, the gibbous moon is 2.2° below Jupiter and 8.3° to the right of Saturn.

Jupiter, Saturn, Moon, August 29, 2020
August 29: One hour after sunset, Saturn is 5.7° to the upper right of the moon and 8.3° to the left of Jupiter that is over 13° to the upper right of the gibbous moon.

On the next evening, August 29, Saturn is 5.7° to the upper right of the bright moon, while Jupiter is 8.3° to the right of the lunar orb.

As the planet parade reaches its conclusion, look for the four bright planets in the morning sky early in the month.  Set your clock for an early rise.  Meanwhile Jupiter and Saturn are easily seen in the evening sky.  The gibbous moon is near them four evenings during August.

(Photos and charts are by the author unless otherwise specified.)

 

Venus in morning sky, August 12, 2020
Astronomy, Sky Watching

2020, August: Brilliant Venus, Morning Star
Venus as it moves among the stars during August 2020
During August 2020 this chart shows the motion of Venus compared to the background stars as it leaves Taurus, moves across Orion’s arm, and passes through Gemini.

 

Sparkling Venus shines from the morning eastern sky during August 2020.

by Jeffrey L. Hunt

The brilliant planet Venus shines from the eastern sky during the pre-sunrise hours of August mornings.

The planet is near the Southern Horn of Taurus, Zeta Tauri (ζ Tau), as the month begins.

During eight mornings, the planet moves across the arm and club of Orion, then into Gemini.  Use a binocular to track the planet among the Hunter’s dimmer stars.  Then Venus moves into Gemini.

Since mid-June, four planets – Venus, Mars, Jupiter, and Saturn – have put on a scintillating morning planet parade.  Venus moves rapidly eastward as Jupiter continues to retrograde. On August 1, the Venus – Jupiter gap is 154°.  Earth is moving away from Jupiter as Venus moves away from our home planet.  This gap continues to widen during August.  By mid-month the gap is about 170°.  Seeing all four planets together in the sky becomes more difficult without unobstructed, cloud free horizons.  On August 25, Earth passes between Venus and Jupiter. This is known as a Venus – Jupiter opposition.  It’s not an observable event, except that these four planets are no longer together in the sky.  Earth passes between Venus and Saturn during early September.

Here are the highlights for Venus:

(It is important to note that Gemini has many bright stars.  Several are highlighted in the following list.  Because of the large number in this part of the sky, choose your favorite stars in the region and watch Venus move compared to that starry background.

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Venus during August 2020

For those without star charts, the diagram at the top of this article identifies the stars by their astronomical alphabet soup of Greek letters and some proper names.  In the notes that follow, the “m” designations are numerical values for star brightness.  Like a golf score, the lower values indicate brighter stars. A star of magnitude 1 is 100 times brighter than one of magnitude 6.

  • August 1 – Venus (V) is 2.1° to the lower right of Zeta Tauri (ζ Tau, m = 3.0).
  • August 6 – V passes 0.5° to the lower right of Chi1 Orionis (χ1 Ori, m = 4.4).
  • August 9 – Early in twilight use a binocular to see V 4.5° to the lower right of Messier 35, a star cluster in Gemini. Lower and more difficult to see.  This is certainly a stretch, but give it a try. V passes 0.5° below Chi2 Orionis (χ2 Ori, m = 4.6).
  • August 11 – V passes 2.5° to the lower right of Eta Geminorum (η Gem, m = 3.3).
  • August 13 – V is 2.4° to the lower right of Mu Geminorum (μ Gem, m = 2.8).
Venus and Moon, August 15, 2020
August 15: The crescent moon is 3.5° to the upper left of Venus.
  • August 15 – The waning crescent moon (25.6 days past New, 16% illuminated) is 3.5° to the upper left of V. V is 0.2° below Nu Geminorum (ν Gem, m = 4.1).
  • August 17 – V is nearly between Gamma Geminorum (γ Gem, m = 1.9) and Epsilon Geminorum (ε Gem, m = 3.0). Venus passes 3.7° to the upper left of γ Gem.
  • August 18 – V is 5.0° to the lower right of ε Gem.
  • August 20 – This morning the planet appears between Castor (α Gem, m =1.6) and γ Gem. The separations are: V – Castor, 15.2° and V – γ Gem, 4.9°.
  • August 21 – V passes between Pollux (β Gem, m = 1.2) and γ Gem. The brilliant planet is 5.6° to the lower left of γ Gem and nearly 14° to the upper right of Pollux.
  • August 23 – V is 0.5° to the lower right of Zeta Geminorum (ζ Gem, m = 4.0).
  • August 25 – V and Jupiter are in opposition.
  • August 26 – V is 2.2° to the lower right of Delta Geminorum (δ Gem, m = 3.5) and 3.1° to the lower left of ζ Gem. Look carefully with a binocular. Venus is to the right of a line that connects δ Gem and Lambda Geminorum (λ Gem, m = 3.6).
  • August 27 – V is to the left of a line that connects δ Gem and λ Gem. V is 2.2° to the lower right of δ Gem and 3.4° to the upper left of λ Gem.
  • August 28 – V is at its maximum rising time interval before sunrise, 222 minutes, as seen from Chicago, Illinois, and other similar latitudes.
  • August 31 – V passes 8.6° to the lower right of Pollux. The brilliant planet is above a line that starts at Pollux and extends through Kappa Geminorum (κ Gem, m = 3.6) and extends to Procyon (α Cmi, m = 0.4) .  The dimmer star is 3.6° to the lower right of Pollux.   

For more about the planets this morning, this article provides a semi-technical description of the planetary activity during August.

 

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Astronomy, Jeffsfavs, Sky Watching

2020, July 20: One Morning, Five Planets
Mercury and Venus, July 20, 2020
2020, July 20: Venus and Mercury shines from the eastern sky. Mercury is over 23° to the lower left of the brilliant planet.

The five bright planets – Mercury, Venus, Mars, Saturn, and Jupiter – are strung across the plane of the solar system from the east-northeast horizon to the southwest skyline.  Simultaneously, five planets are visible.

Update:  The planets on July 23, click here.

by Jeffrey L. Hunt

This morning the five bright planets appear as beads on a necklace that is stretched across the morning sky.

Mercury, July 20, 2020
2020, July 20: Without the moon this morning, Mercury shines from low in the east-northeast during morning twilight. It is over 23° to the lower left of brilliant Venus.

Without the moon, Mercury shines low in the east-northeast, to the lower left of brilliant Venus.  Mercury is in the sky for several more mornings until it disappears back into the sun’s glare.  In two mornings it reaches its greatest separation (elongation) from the sun.  It never strays far from the sun’s glare, making it a challenge to view.

Venus in Taurus, July 20, 2020.
2020, July 20: In the east, brilliant Venus shines from among the stars of Taurus, 5.1° to the lower left of the star Aldebaran. The Hyades star cluster and Pleiades star cluster are nearby.

Brilliant Venus is to the upper right of Mercury.  Before later twilight brightened the sky, Venus is visible 5.1° to the lower left of Aldebaran.  This star along with the Hyades star cluster form the face of Taurus the Bull.  The Pleiades star cluster is above the scene.

Mars in Cetus, July 20, 2020
2020, July 20: Mars shines from the stars of Cetus in the southeastern sky during early morning twilight. It is 2.7° to the upper left of 20 Ceti (20 Cet).

Meanwhile, Mars is the lone bright “star” in the southeast among the dim stars of Cetus.  This morning it is 2.7° to the upper left of 20 Ceti (20 Cet on the photo). A binocular is needed to see the starfield.

Mars is marching eastward.  It begins the illusion of retrograde motion in early September as Earth approaches and passes the planet.  Earth is between the sun and Mars on October 13, 2020.  On this date, the sun and planet are in opposite directions from Earth.  Near opposition the outer planets are closest to Earth and brightest in the sky.

Jupiter and Saturn in the southwest, July 20, 2020
2020, July 20: Saturn and brighter Jupiter appear in the southwest among the stars of Sagittarius. Jupiter is 4.0° to the lower right 56 Sagittarii (56 Sgr), while Saturn is 4.3° to the lower right of Sigma Capricorni (σ Cap).

Saturn and Jupiter are farther west in eastern Sagittarius.  The planets are retrograding – moving westward compared to the background stars. With a binocular check the planets’ positions compared to the starry background.  This morning Saturn is 4.3° to the lower right of Sigma Capricorni (σ Cap), while Jupiter is 4.0° to the lower right 56 Sagittarii (56 Sgr).

Jupiter was at opposition last week and Saturn is at opposition today.  Jupiter and Saturn appear to reverse their directions in September.  Then Jupiter inches toward Saturn and passes it on December 21, 2020 for a Great Conjunction.

Continue to look for the five planets for the next several days.

Here’s more about the planets during July.

 

Astronomy, Jeffsfavs, Sky Watching

2020, July 17: Spectacular Crescent Moon in Morning Planet Parade
The crescent moon, Venus, Aldebaran and the Pleiades, July 17, 2020.
2020, July 17: The crescent moon is in a group with Venus and Aldebaran as the Pleiades appear above the scene during early morning twilight.

This morning’s crescent moon joins Venus in the eastern sky.  Four planets arch across the morning sky.

by Jeffrey L. Hunt

Venus, the crescent moon, and Aldebaran, July 17, 2020.
2020, July 17: The crescent moon is 3.2° to the left of Venus and the brilliant planet is the same distance to the lower left of Aldebaran.

A thin crescent moon joins brilliant Venus this morning in the eastern sky.  The star Aldebaran, in Taurus the Bull, appears nearby.  The moon is 3.2° from Venus, and the sparkling planet is the same distance from Aldebaran.

Mars in Cetus, July 17, 2020.
2020, July 17: Mars, in the southeast, is 2.9° to the upper right of 20 Ceti (20 Cet).

Higher in the southeast, bright Mars shines from the dim stars of Cetus.  It continues to march eastward compared to the starry background.  This morning it is 2.9° to the upper right of 20 Ceti (20 Cet on the photo).

Earth passes between Mars and the sun on October 13.  This is known as opposition.

Jupiter and Saturn in eastern Sagittarius, july 17, 2020.
2020, July 17: Jupiter is 3.7° to the lower right of 56 Sagittarii (56 Sgr) and 1.6° to the upper left of 50 Sagittarii (50 Sgr). Saturn is 4.1° to the lower right of Sigma Capricorni (σ Cap).

Jupiter and Saturn are in the southwestern sky in front of the stars of eastern Sagittarius.  They are moving westward compared to the stars.  This illusion of backwards motion occurs when Earth passes worlds beyond our planet.

Jupiter is a few days past its opposition. Earth passes between the sun and Saturn on July 20.  Both planets continue to retrograde until September.  When they again resume their eastward motion compared to the stars, Jupiter approaches and passes Saturn in a Great Conjunction on December 21, 2020.

This morning, Jupiter is 3.7° to the lower right of 56 Sagittarii (56 Sgr) and 1.6° to the upper left of 50 Sagittarii (50 Sgr).  Saturn is 4.1° to the lower right of Sigma Capricorni (σ Cap).

Here’s more about the planets during July.

 

Astronomy, Sky Watching

2020, July 14: Planet Parade, Moon, Comet

 

Comet NEOWISE, July 14, 2020
2020, July 14: Comet NEOWISE shines from the northeastern sky.

 

Four planets, Moon, and a comet parade across July’s morning sky.

by Jeffrey L. Hunt

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

 

The waning crescent moon, July 14, 2020.
2020, July 14: The moon is in the eastern sky. It is 23.4 days past its New phase and 37% illuminated. It is a thick waning crescent phase.

Overnight Earth passed between the sun and Jupiter.  This is known as opposition.  Saturn’s opposition is July 20.  At opposition, planets are bright in the sky.  They are opposite the sun in the sky.  The rise in the east when the sun sets in the west, move across the sky all night, and set in the west at sunrise.

The moon appears between Venus and Mars in the eastern sky.

Venus in Taurus, July 14, 2020.
2020, July 14: Venus is 1.6° to the left of Aldebaran. The Pleiades star cluster appears above the pair.

Venus is moving eastward through Taurus the Bull.  Aldebaran and the Hyades star cluster form a sideways “V” that makes the Bull’s head.  Venus is 1.6° from Aldebaran this morning.

In a few mornings (July 17) the moon appears with Venus and Aldebaran.  With the Pleiades in view, this will be a picturesque scene!

Mercury joins the planet parade beginning July 19, when the “Classic 9” planets are in the sky simultaneously with the moon, about 45 minutes before sunrise. 

Venus, Moon, and Mars, July 14, 2020.
2020, July 14: Venus, Moon, and Mars span nearly 62° in the eastern morning sky.

The moon is between Venus and Mars. The Venus – Mars gap is nearly 62°. 

Mars is Cetus, July 14, 2020.
2020, July 14: Mars is 1.3° to the upper left of 14 Ceti (14 Cet).

The Red Planet is marching eastward in front of the stars of Cetus.  It is at opposition on October 13, 2020.

For observers with large-aperture telescopes, Uranus, Neptune, and Classic Planet Pluto are visible as well.

Comet NEOWISE is appearing in the morning and evening sky.  This morning it is low in the northeast during early morning twilight.

Jupiter and Saturn in Sagittarius, July 13, 2020.
2020, July 14: Saturn is 6.8° to the upper left of the Jupiter. Jupiter 3.4° is to the lower right of 56 Sagittarii (56 Sgr), while Saturn is 3.9° to the lower right of Sigma Capricorni (σ Cap).

Farther west, Jupiter and Saturn are retrograding in eastern Sagittarius.  Later in the year, after the giant planet pair reverses course, Jupiter passes closely to Saturn in a Great Conjunction, the closest since 1623.

These Jupiter – Saturn groupings occur once every 19.6 years.  This is the closest grouping since 1623, although the records are unclear whether it was observed.  The pair was close to the sun when Jupiter passed.

In the photo above at least one of Jupiter’s largest moon’s is visible.

Here’s more about the planets during July.

 

Astronomy, Sky Watching

2020, July 13: Jupiter at Opposition Leads Planet Parade
Jupiter at opposition and Saturn, July 13, 2020.
Jupiter, at opposition, leads the July planet parade. See Jupiter, Saturn, Mars, and Venus before sunrise.

Jupiter, at opposition, leads the July planet parade.  Saturn is at opposition July 20, 2020.

by Jeffrey L. Hunt

Bright Jupiter is at opposition.  Earth is between the sun and this giant planet.

At opposition the planet is very bright in the sky because it is closest to Earth.

Jupiter rises at sunset.  It appears in the south around 1 a.m., midnight when daylight time is not in effect.  The planet sets in the southwest at sunrise.

Saturn is 6.7° to the lower left of Jupiter.  Earth passes between the sun and Saturn on July 20.

This planetary pair is retrograding in eastern Sagittarius.  This apparent motion is an illusion as our faster moving Earth overtakes, passes between the sun and planet, and moves away from the planet.

This motion was the cosmological problem of early astronomers.  The philosophical part of the issue was whether the sun was at the center of the universe or the Earth held the central position.

With a stationary Earth at the center, several circles were employed to make the planetary models fit what was occurring in the sky.  With a central sun and a fast-moving earth, the retrograde motion was an optical illusion.

Earth’s revolution around the sun was not measured until the 19th Century.  Retrograde motion is an illusion.

Both planets retrograde until September, but as they continue to move westward compared to the starry background, the gap continues to grow.

When they reverse direction, Jupiter inches toward Saturn.  Jupiter slowly overtakes and passes the Ringed Wonder.  This Great Conjunction occurs on December 21, 2020.

This is the closest conjunction of Jupiter and Saturn since 1623, although there is little evidence that this conjunction was observed.

Mars follows the Jupiter – Saturn pair across the horizon after midnight.  It clears the landscape by 1 a.m. and appears low in the eastern sky.  The moon rises about an hour after Mars (on July 14).

As Earth rotates, Jupiter, Saturn, Mars, and the moon appear farther west.

By the beginning of morning twilight, Jupiter and Saturn are in the south-southwest and Mars is in the southeast.  The moon is to the lower left of Mars.

Venus then rises into the east-northeast sky.  It is near Aldebaran in Taurus.

As the sky brightens, the four bright planets and the moon stretch across the sky from the east-northeast horizon to the southwest skyline.

Mercury joins the planet parade beginning July 19, when the “Classic 9” planets are in the sky simultaneously with the moon, about 45 minutes before sunrise. 

For observers with large-aperture telescopes, Uranus, Neptune, and Classic Planet Pluto are visible as well.

In a few mornings (July 17) the moon appears with Venus and Aldebaran.  With the Pleiades in view, this will be a picturesque scene!

The four bright planets, Venus, Mars, Jupiter, and Saturn, are visible in the morning sky until about mid-August, although at an earlier hour as August progresses.

Here’s more about the planets during July.

Astronomy, Sky Watching

2020, July 13: A Morning Planet Parade, Moon, Comet
Comet NEOWISE, July 13, 2020
2020, July 13: Comet NEOWISE (Comet C/2020 F3 NEOWISE) appears above the northeast horizon during early morning twilight.

Comet NEOWISE appears with the moon in July’s morning planet parade.

More about the comet, planets and moon on July 14, click here.

by Jeffrey L. Hunt

Comet NEOWISE appears in the morning sky during twilight this morning in the northeast.

The comet (formally known as Comet C/2020 F3 NEOWISE) is now appearing in the evening sky as well as making its mark in the morning sky.

Comets are orbiting icebergs.  They travel around the sun in elongated orbits.  When near the sun, the solar energy vaporizes the ices.  Solar wind – a stream of particles from the sun – drives the gasses and dust into space.

The intense sunlight fractures many comets into smaller pieces.  Comet NEOWISE survived its close solar passage and it is the summer surprise with the July morning planet parade that stars Venus, Mars, Saturn, and Jupiter.

Mercury joins the planet parade beginning July 19, when the “Classic 9” planets are in the sky simultaneously with the moon, about 45 minutes before sunrise.

Mars in Cetus, July 13, 2020
2020, July 13: Mars is 0.8° to the upper left of 14 Ceti (14 Cet).

The thick crescent moon appears to the lower left of Mars this morning.  The image above uses a roofline to block the moon’s light so that the starry background is visible.

Mars is marching eastward in the constellation Cetus.  This region of the sky does not have many bright stars.  A binocular is helpful to watch Mars appear farther east among the stars each morning. 

This morning, Mars 0.8° is to the upper left of dim 14 Ceti (14 Cet on the photo).  Notice that it is also east of 10 Ceti (10 Cet) and to the lower left of 44 Piscium (44 Psc).

Mars continues to move eastward until early September.  Afterwards it appears to move westward – retrograde – compared to the background stars.  Earth passes between the sun and Mars on October 13, 2020.  This is known as opposition.

Jupiter and Saturn in eastern Sagittarius, July 13, 2020
2020, July 13: Jupiter is 3.3° to the lower right of 56 Sagittarii (56 Sgr). Saturn is 3.8° to the lower right of Sigma Capricorni (σ Cap).

Jupiter is at opposition tomorrow.  It rises in the eastern sky at sunrise and sets in the western sky at sunrise.

This morning, Jupiter, along with Saturn, is in the southwest.  Saturn is at opposition on July 20.

The planets are retrograding in eastern Sagittarius.  The Jupiter – Saturn gap is 6.7°.  Their separation widens until September when they reverse their apparent direction.  Jupiter closes in and passes Saturn in a Great Conjunction on December 21, 2020.

These conjunctions occur about every 19.6 years because these planets move slowly around the sun.

In the starfield this morning, Jupiter is 3.3° to the lower right of 56 Sagittarii (56 Sgr).  Saturn is 3.8° to the lower right of Sigma Capricorni (σ Cap).  Each morning compare the positions of the planets to the reference stars.

At least one of the four largest Jovian moons is visible in the image – Callisto.

Venus and Aldebaran, July 13, 2020
2020, July 13: Venus appears 1.2° to the left of Aldebaran.

The “star” of the morning planet parade is brilliant Venus.  It is visible low in the east-northeast, in front of the stars of Taurus the Bull.  The brighter star Aldebaran and dimmer stars (Hyades star cluster) seem to form a sideways “V” that makes the head of the Bull.  Aldebaran represents the bull’s eye.

This morning, the planet is 1.2° to the left of Aldebaran.

Venus, Aldebaran, Hyades, Pleiades, July 13, 2020.
2020, July 13: Venus, Aldebaran, Hyades, Pleiades appear in the early morning sky.

In a few mornings (July 17) the moon appears with Venus and Aldebaran.  With the Pleiades in view, this will be a picturesque scene!

Here’s more about the planets during July.

 

Astronomy, Sky Watching

2020, July 11: Unusual Surprise in July’s Morning Planet Parade
Comet NEOWISE, July 11, 2020
2020, July 11: Comet NEOWISE shines from low in the northeast sky during early morning twilight. It is to the lower left of the star Capella.

Cosmic interloper Comet NEOWISE Marches in July’s morning planet parade.

by Jeffrey L. Hunt

Comet NEOWISE joins the morning planet parade again this morning.  The unexpected surprise in the morning sky this year is the comet.  It joins a parade of planets in the pre-sunrise sky.

As the photo indicates, Comet NEOWISE (formally known as Comet C/2020 F3 NEOWISE) is low in the northeastern sky during early morning twilight.  Find a clear horizon (or a gap in the trees or houses) to see it.  The comet is easy to see without a binocular or telescope, but a binocular assists in finding the location.

The comet is to the lower left of the bright star Capella.

Comets are icy debris, theorized to be left over from the formation of the solar system.  Normally invisible, these frozen icebergs vaporize when they approach the sun, forming the comet’s characteristic tail.

Many comets are observed every year, but infrequently they become bright enough to be seen without a telescope.  Comet NEOWISE is the best visual comet seen from the northern hemisphere since Comet Hale-Bopp that was visible in 1997.

Comet NEOWISE becomes visible higher in the evening sky in a few evenings as well as shining in the morning sky.

Venus and Aldebaran, July 11, 2020
2020, July 11: Brilliant Venus appears 1.0° to the upper left of the star Aldebaran. The Pleiades star cluster appears above Venus.

Meanwhile the planet parade continues from the east-northeast tree line to the southwest skyline.  The current best part of this parade is Venus appearing to move through the Hyades star cluster. The mass of stars, along with Aldebaran, makes a sideways “V” that represents the head of Taurus the Bull.

This morning Venus is 1.0° to the upper left of Aldebaran.  A binocular helps when identifying the changing position of Venus in Taurus.

The moon is in the region on the morning of July 17, grouping with Venus, Aldebaran, and the Hyades.  With the Pleiades nearby, this will be a picturesque view.  Get your camera ready for this spectacular scene!

Mercury joins the planet parade beginning July 19, when the “Classic 9” planets are in the sky simultaneously with the moon, about 45 minutes before sunrise.

Farther west, the gibbous moon is to the right of Mars.  Its brightness, causes an extra image in the photo above.

Mars and the moon in Cetus, July 11, 2020
2020, July 11: Mars is 0.7° to the upper right of dim 14 Ceti) (14 Cet) and 2.7° below 44 Piscium (44 Psc).

Mars is marching eastward in the constellation Cetus, near the dim star 14 Ceti (14 Cet on the photo above) and below 44 Piscium (44 Psc).  Watch it continue to move eastward with a binocular.

Mars is at opposition on October 13, 2020.

Jupiter and Saturn in Sagittarius, July 11, 2020
2020, July 11: Jupiter shines from the southwest. Saturn is 6.6° to Jupiter’s upper left. In the starfield, Jupiter is 3.0° below 56 Sgr. Saturn is 3.6° to the lower right of σ Cap.

Still Farther west, Jupiter and Saturn are low in the southwestern sky.  They are retrograding in eastern Sagittarius.  This perceived motion is an illusion as our planet approaches and passes a planet farther from the sun than Earth.  We pass between Jupiter and the sun on July 14 and Saturn 6 days later.

In the image above, note that Jupiter is to the lower right of 56 Sagittarii (56 Sgr).  If you enlarge the image, you can see at least one of the four largest jovian satellites.

Saturn is to the lower right of Sigma Capricorni (σ Cap).

With a binocular watch the planets move away from the star referenced on the image during the next several days.

Jupiter and Saturn reverse their directions in September.  Jupiter inches toward Saturn, passing it on December 21, 2020 in a Great Conjunction.  This once-in-a-generation conjunction is the closest since the Jupiter – Saturn conjunction of 1623.

For more about the planets see this article about where to find them during July.