Tag: Jupiter

Astronomy, Sky Watching

2019, July 9: Saturn at Opposition

On July 9, Saturn is at opposition, nearly a month after Jupiter was in the opposite direction in the sky from the sun.

Saturn is near opposition for several nights before and after reaching this point opposite the sun.  To locate the planet step outside after the sky darkens.  The chart above shows the sky about 90 minutes after sunset; check your sources for the time of sunset at your location. (For example, in Chicago, Illinois, the time for the above chart is 10 p.m. CDT.  Near Omaha, Nebraska, 90 minutes after sunset is 10:30 p.m. CDT.)

Jupiter is the bright “star” that is almost south, but less than one-third of the way up in the sky.  Golden-orange Antares is to the lower right of Jupiter.  Saturn is farther left of Jupiter in the southeast, lower in the sky than Jupiter.  Saturn is among the stars of Sagittarius, brighter than those surrounding stars, but not as bright as Jupiter.  For perspective, the moon is outside the chart.  The gibbous moon is in the southwest, above the bluish star Spica.  On July 15, the nearly full moon is to the right of Saturn.

Through a telescope, the planet’s rings are revealed.  If you’re careful, you might see its a few of its moons, depending on the diameter of the lens or the mirror and the magnification that is used.  The large gap in the rings, Cassini’s Division, might be seen as well.

Viewing Saturn through a telescope is one of life’s memorable experiences.  If you view this spectacular ringed wonder through a telescope, you will certainly remember.  A child will remember this experience.

Opposition occurs when Earth passes between a planet farther from the sun than Earth (Mars, Jupiter, Saturn, Uranus, and Neptune) and the sun.  The planet rises at sunset, appears in the south around midnight, and sets in the west.  When at opposition, the outer planets are closest to Earth, at their brightest points in the sky, and provide the best telescopic views.

Saturn appears at opposition again on July 20, 2020, when it reaches that point just six days after Jupiter’s opposition.  Jupiter passes Saturn in December 2020 for a Great Conjunction that occurs about every 20 years.

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Astronomy, Sky Watching

2019, June 10: Jupiter at Opposition
Jupiter (NASA Photo)

Jupiter reaches opposition on June 10, 2019.  On that evening, and for a few evenings around that date, Jupiter rises in the southeast at sunset. As the sky darkens further, Jupiter appears higher in the sky.

At this time the planet is about 450 million miles away, yet it looks like a bright star.  The planet is to the left of the golden-orange star Antares.

Jupiter’s oppositions occur about every 400 days, about 35 days longer than an Earth year.  The planet is slower moving than Earth. Jupiter revolves around the sun about every 11.8 (earth) years.

Jupiter moves on a longer track and at a slower speed than Earth.

Once Earth moves between Jupiter and the sun, it speeds away and catches up with Jupiter again in about a year and 35 days.

While we remark that Jupiter is at opposition, this description is related to the notion that earth is stationary and immobile.  While it is inaccurate, it relates to the apparent movement of the heavens, in the same way we use “sunrise” and “sunset.”  Both solar events are from Earth’s rotation.

When Jupiter, and other planets outside Earth’s orbit, appears at opposition, it is at its closest point to Earth.  The planet rises at sunset, appears at its highest in the south at midnight, and sets in the western sky at sunrise.

After opposition, Jupiter appears higher in the sky each night at the same time.  In several weeks it appears in the south at sunset.  It disappears into sun’s glare in December.

If you have access to a telescope, Jupiter is a spectacular sight in that telescopic view.  The colors of its cloud bands are revealed and sometimes the Great Red Spot is visible.  The Red Spot is sometimes described as a long-lived storm.  It’s been observed in the clouds for over 400 years!

Jupiter’s four largest moons appear in the telescope as well.  They look like stars.  The moons are lined up in the equatorial plane.  They are visible through a binocular as well, if you can hold the optics steady enough to see them.

Go outside and take a look for Jupiter in the early evening sky!

Astronomy, Sky Watching

2019, May 19-21: Moon Passes Jupiter

As Jupiter approaches opposition, the event when our planet Earth is between Jupiter and the sun.  Jupiter and the sun are in opposite sides of the sky.  Jupiter rises when the sun sets and Jupiter sets when the sun rises.  Jupiter is in the south at midnight, when the sun is in the south at noon.

A few weeks before opposition, Jupiter appears in the evening and the morning sky.  Here’s what’s to see depending on when you step outside to see it.

Evening

  • May 19: At 10:30 p.m. CDT, the moon, 15.2 days past its New phase and 98% illuminated, is nearly 7° to the upper right of Jupiter and almost 9° to the left of Antares in the southeastern sky.

  • May 20: At 11 p.m. CDT, the moon, 16.2 days old and 94% illuminated, is nearly 7° up in the southeast and 6.5° to the lower left of Jupiter.

Morning

By morning , the moon appears in the southwest.

  • May 20:  At the beginning of morning twilight (about 4 a.m. CDT), the moon, 15.4 days old and 98% illuminated, is 4.6° to the right of Jupiter.  The Giant planet is 24° up in the south-southwest.

  • May 21:  At the beginning of morning twilight, the moon, 16.5 days old and 93% illuminated, is 25° up in the south and 8.2° to the left of Jupiter.

 

Astronomy, Sky Watching

2019, April 22-26: The Morning Moon With Jupiter and Saturn

The moon moves past the morning planets — Jupiter and Saturn — during late April 2019.  The chart above shows them about one hour before sunrise.  Check your local sources — TV, newspaper, Internet — for your local sunrise time.  Here are the highlights of the mornings:

  • April 22: At the beginning of morning twilight, the moon (17.0 days old. 90% illuminated), nearly 28° up in the south-southwest, is over 7° to the upper right of Antares.
  • April 23: At 12:30 a.m. CDT, the moon (17.9d, 90%), about 10° up in the southeast, is 2.8° to the upper right of Jupiter. At the beginning of morning twilight, the moon (18.0d, 82%) is 1.5° to the upper right of Jupiter, 25° up in the south. Saturn is 20° up in the south-southeast, about 26° east of Jupiter.
  • April 24: At the beginning of morning twilight, the moon (19.0d, 74%) is nearly between Jupiter and Saturn. The moon is at the top of the lid of the Teapot of Sagittarius, above Kaus Borealis.
  • April 25: At the beginning of morning twilight, now 105 minutes before sunrise, the moon (20.0d, 65%) is 2.7° to the lower right of Saturn.
  • April 26: At the beginning of morning twilight, the moon (21.0d, 55%) is 9.8° to the lower left of Saturn.
Astronomy, Sky Watching

2019, March 26-29: Moon Glides Past Morning Planets Jupiter and Saturn

During late March, the moon glides past morning planets Jupiter and Saturn.  The chart above shows the scene about 45 minutes before sunrise.  Check your newspaper, television weather, or Internet source for the time of your local sunrise.  These observations are not time sensitive because the moon and planets are higher in the sky than earlier in the year.

Step outside before sunrise and look south.  Bright Jupiter is there about one-third of the way up in the sky.  Saturn is about 25° to the lower left of Jupiter.  Here’s what to look for:

  • March 26: This morning, the waning gibbous moon that is 68% illuminated is nearly 9° to the upper right of bright Jupiter
  • March 27: This morning. the nearly last quarter moon that is nearly 60% illuminated is over 4° to the left of Jupiter. Notice the distance that the moon moved from yesterday. With a binocular notice that the day-night line (terminator) on the moon is slightly convex – bowed outward.
  • March 28: At the beginning of morning twilight, the thick crescent moon that is 48% illuminated, 19° up in the south-southeast, is 9° to the right of Saturn.   This morning the terminator is slightly concave – bowed in.
  • March 29: This morning, the moon that is 38% illuminated, 14° up in the southeast, is about 3° to the lower left of Saturn.  Notice the amount the moon phase shrank during these mornings.

Look for the moon and Venus on April 1.

More about measurements.  Degrees (°) are used in astronomy to measure separation of celestial objects and sizes of objects as they appear to us, not their real sizes, their apparent sizes.   One-half degree is the apparent size of the moon.  The next time you see the moon in the sky, extend your arm and then your pointer finger.  The tip of the finger, with the finger nail, covers the moon.  Your fist extended toward the sky covers about 10°.  So, on March 26, the distance between the moon and Jupiter is about the distance across your fist.  The next morning about three knuckles is the distance between the moon and Jupiter.

More about the morning planets:

 

Astronomy, Feature, Sky Watching

2019: Winter Morning Planet Parade Album

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On a recent trip to a more southerly latitude, the morning planets presented themselves high in the sky.  This album shows them on the mornings of February 28, March 1, and March 2, 2019.  When travelling farther south, the southern stars and planets appear higher in the southern sky.

Astronomy, Sky Watching

2019, March 4: Morning Star Venus, Saturn, and Jupiter
2019, March 4: Venus, Saturn, and Jupiter

Brilliant Morning Star Venus, now appearing low in the southeast, shines during morning twilight with Saturn and Jupiter.  The Venus-Saturn gap is 15 degrees.  Jupiter is farther toward the south, over 25 degrees to the upper right of Saturn.

More about the morning planets: