Jupiter Today | 04 August 2015 | All Together Now

Hello!

JUPITER TODAY is a daily blog about the dynamic Jupiter system for the purpose of monitoring activity.

We start with the overall view of activity with the Jupiter system, showing the orbits of the four Galilean moons:

This is a view of the Jupiter system looking down on it.  The blue line is the line of sight to Earth, while the gray line is the line of sight to the Sun.  The orbits of the four Galilean moons are shown.  The large dots indicate the position of each moon at 0h, 6h, 12h, 18h, and 24h (0h the next day) UTC for this date.  From this point of view, the moons revolve around Jupiter in a counter-clockwise motion.  For more information about this graphic, see the post from 30 July 2015.

At 0h UTC, Io begins the day in quad 4 moving east.  Europa is in quad 2 moving west.  Ganymede is moving behind Jupiter and will be in quad 1 moving east the rest of the day.  Callisto starts the day in quad 4 moving east.

By 6h UTC, Io is moving behind Jupiter along with Ganymede.  Europa is on the opposite side of Jupiter transiting the planet.

At 12h UTC, Io and Ganymede have moved behind Jupiter and are now firmly in quad 1 moving east.  Europa is now firmly in quad 3 moving east.

At 18h UTC, Io has moved past its eastern elongation and is now in quad 2 moving west.  Callisto is now moving behind Jupiter and into quad 1 heading west

By 0h UTC tomorrow, Io is firmly in quad 2 moving west.  Europa is in quad 3 moving west very near its western elongation.  Ganymede and Callisto are in quad 1 moving east.

At 07:19 UTC, Europa goes through a perijove (the closest it will be to Jupiter in this orbit) at a distance of 664,478.4 km.  At 7:22 UTC, Io goes through a perijove at a distance of 420,032,1 km.  Note that these two perijoves take place on nearly opposite sides of the planet.

At 0h UTC, Jupiter's position on Earth's celestial sphere is an RA of 10h 02m 38.3s and a DEC of 12d 54m 28.5s.  This phase angle is 3.177 degrees, which is 0.134 degrees less than yesterday.  The angular separation between Jupiter and the Sun as seen from Earth is 17.095 degrees, which is 0.743 degrees less than yesterday.  The distance between Jupiter and the Sun today is 805,204,348 km, which is 37,620 km further away than yesterday.  This gives a radial velocity of 1,567.5 km/h moving away from one another, and this is 0.083 km/h slower than yesterday.  Notice how these small changes in velocity correlate with the positions of the moons.  The distance between Jupiter and the Earth is 949,049,817 km, which is 717,430 km further away than yesterday.  This translates to a radial velocity of 29,892.9 km/h, which is 1214.75 km/h slower than yesterday.

At 01:24 UTC, Ganymede moves behind Jupiter.  From 03:51 to 06:43 UTC, Europa transits Jupiter.  from 04:35 to 07:26 UTC, Europa's shadow transits Jupiter.  At 05:08 UTC, Io moves behind Jupiter.  At 06:32 UTC, Ganymede reappears from Jupiter's shadow.  At 07:47 UTC, Io reappears from Jupiter's shadow.  At 13:48 UTC, Callisto moves behind Jupiter.  At 21:53 UTC, Callisto reappears from Jupiter's shadow.

There are no satellite mutual events today.

Orbital Ribbons for today:

Even though Jupiter is near Superior Conjunction (taking place on 26 August 2015), please send me your pictures of Jupiter!  If you do, I'll post them to this blog!  Please also include the time (in UTC if possible) you took the image, the telescope you used, the camera you used, and any other information you might think is useful.

Spread the word about this daily blog!  This blog is subject to evolution.  What can I do to make this blog more interesting and more informative?

Please send me your feedback, comments, and questions to jupitertoday AT gmail DOT com.

With my gratitude, the data used to create the orbit plots and ribbons was supplied by the JPL Horizons website.  The graphics showing the location of the four moons as seen from Earth are via 'Jupiter Viewer 2.8'.  Jupiter-Satellite and Satellite mutual events data is supplied from IMCEE.

Until tomorrow, I bid you Peace. 

What Is Jupiter Today?

'Jupiter Today' is a blog focusing attention on the dynamic Jupiter system for the purpose of monitoring activity.  Please join me every day as I report on events taking place over the next 24 hours at, and in the environment of, our solar system's largest planet.  Detailed information and graphics include:

1. The position of Jupiter on the celestial sphere
2. The distance to, and relative motions of Jupiter and Earth
3. The motions of the four Galilean satellites in their orbits around Jupiter
4. Jupiter-satellite interactions
5. Satellite mutual events
6. Where and when to observe predicted Jupiter events on Earth
7. Recent images and data
8. Recently published research papers

New blogs are published every day.

This blog is part of a larger project to create a world-wide system of continuous, or near-continuous, observations of the Jupiter system.  There are many new discoveries to be made about Jupiter and leaving these discoveries to chance is unacceptable.  Long-term, high cadence monitoring is the only way to make these discoveries.  Data collected with this method will allow researchers to test and/or update current theories which can then guide future observations.

Observations and discoveries will lead to questions requiring more observations, which will inevitably lead to more discoveries and more questions.

Some of these observations will include images showing weather on and in the local environment of Jupiter.  Images that I acquire (ones that I take, ones emailed to me, or ones I find on the internet) will be stored in a simple database that can then be queried to access relevant images covering specific dates and times.  This will allow those interested to study the weather on Jupiter and see how it changes daily, seasonally, and during hightened solar activity (like when a coronal mass ejection reaches the Jupiter system).

Other observations will include how the moons of Jupiter interact with the planet and each other.  This will require some well-calibrated cameras and other instruments to do astrometry, photometry, and spectroscopy.  To my knowledge this work has never been done over a long period of time at high cadence.

There will be observations of events that no one is expecting.  When you continuously watch a highly dynamic system for a long period of time, what do you see?  This project will answer some of that.

Please read, like, and subscribe!  Tell your friends about this project, too!  Comments and constructive criticism are welcome.

Until tomorrow --- I bid you Peace

Jupiter Today | 03 August 2015 | Jupiter Hug

Good Day!

JUPITER TODAY is a daily blog about the dynamic Jupiter system for the purpose of monitoring activity.

We start with the overall view of activity with the Jupiter system, showing the orbits of the four Galilean moons:

This is a view of the Jupiter system looking down on it.  The blue line is the line of sight to Earth, while the gray line is the line of sight to the Sun.  The orbits of the four Galilean moons are shown.  The large dots indicate the position of each moon at 0h, 6h, 12h, 18h, and 24h (0h the next day) UTC for this date.  From this point of view, the moons revolve around Jupiter in a counter-clockwise motion.  For more information about this graphic, see the post from 30 July 2015.

At 0h UTC, Io begins the day just past eastern elongation and in quad 2 moving west.  Europa starts the day in quad 1 moving east.  Ganymede spends all day in quad 4 moving east along with Callisto.

By 6h UTC, Io is now firmly in quad 2 moving west.  Europa is near it eastern elongation and will be moving into quad 2 moving west.  So by about this time, the two inner Galilean moons are moving west, while the two outer Galilean moons are moving east.  All of them are moving towards Jupiter for a big group Hug.

At 12h UTC, Io has transited Jupiter and is now in quad 3 moving west.  Europa is past its eastern elongation and will spend the rest of the day in quad 2 moving west

By 18h UTC, Io is in quad 3 moving west but getting near its western elongation.

At 0h UTC tomorrow, Io is in quad 4 moving west.  Europa is still in quad 2 moving west and will soon be transiting Jupiter.  Ganymede is still in quad 4 moving east and will be moving behind Jupiter.  Callisto spends a few more hours in quad 4 when it too will appear to move behind Jupiter from Earth's point of view

At 10:06 UTC, Io goes through an apojove at a distance of 423,485.1 km.  Ganymede goes through an apojove (the furthest it will be in this orbit) at 17:08 UTC at a distance of 1,071,623.4 km.

Io transits Jupiter from 07:51 to 10:10 UTC.  That's a 133 minute transit.  Io shadow transits Jupiter from 08:14 to 10:32 UTC.

There are no satellite mutual events today.

A nice set of Orbital Ribbons today:

At 0h UTC, the position of Jupiter on Earth's celestial sphere is RA 10h 01m 49.3s, DEC +12d 58m 52.0s.  The phase angle today is 3.311 degrees, which is 0.134 degrees less than what it was yesterday.  The angular separation between Jupiter and the Sun as seen from Earth is 18.582 degrees, which is 0.744 degrees less than what it was yesterday.  The distance between Jupiter and the Sun is 805,166,728 km, which is 37,622 km further apart that yesterday.  This gives a radial velocity between Jupiter and the Sun of 1,567.6 km/h, which is 2.417 km/h slower than yesterday.  The distance between Jupiter and the Earth is 948,332,387 km, which is 746,584 km further apart than yesterday.  This gives a radial velocity between Jupiter and the Earth of 31,107.7 km/h, which is 1211.1 km/h slower than yesterday.

Even though Jupiter is near Superior Conjunction (taking place on 26 August 2015), please send me your pictures of Jupiter!  If you do, I'll post them to this blog!  Please also include the time (in UTC if possible) you took the image, the telescope you used, the camera you used, and any other information you might think is useful.

Spread the word about this daily blog!  This blog is subject to evolution.  What can I do to make this blog more interesting and more informative?

Please send me your feedback, comments, and questions to jupitertoday AT gmail DOT com.

With my gratitude, the data used to create the orbit plots and ribbons was supplied by the JPL Horizons website.  The graphics showing the location of the four moons as seen from Earth are via 'Jupiter Viewer 2.8'.  Jupiter-Satellite and Satellite mutual events data is supplied from IMCEE.

Until tomorrow, I bid you Peace.

Jupiter Today | 02 August 2015 | Io and Europa

Hello!

JUPITER TODAY is a daily blog about the dynamic Jupiter system for the purpose of monitoring activity.

As Jupiter moves towards Superior Conjunction on 26 August 2015, it gets more and more difficult to view and monitor.

We start with the overall view of activity with the Jupiter system, showing the orbits of the four Galilean moons:

This is a view of the Jupiter system looking down on it.  The blue line is the line of sight to Earth, while the gray line is the line of sight to the Sun.  The orbits of the four Galilean moons are shown.  The large dots indicate the position of each moon at 0h, 6h, 12h, 18h, and 24h (0h the next day) UTC for this date.  From this point of view, the moons revolve around Jupiter in a counter-clockwise motion.  For more information about this graphic, see the post from 30 July 2015.

At 0h UTC, Io begins the day near western elongation moving into quadrant 4 heading east.  Europa is also in quad 4 heading east.  As you can see from the orbit plot above, Io and Europa appear near each other from our POV most of the day today.  Ganymede starts the day in quad 3 moving west.  Callisto will spend all day in quad 4 heading east towards Jupiter.

At 6h UTC, Io and Europa are now firmly in quad 4 moving east.  Ganymede is near its western elongation.

By 12h UTC, Io and Europa are both moving behind Jupiter.  Ganymede has passed its western elongation and is now in quad 4 heading east.

At 18h UTC, Io and Europa have successfully moved behind Jupiter and are now in quad 1 moving east.

By 0h UTC tomorrow, Io has just gone thought its eastern elongation and is now in quad 2 moving west.  Europa is still in quad 1 moving east.  Ganymede and Callisto are in quad 4 moving east.

At 12:48 UTC, Europa is at apojove at a distance of 677,662.8 km.  Io is at perijove at 13:04 UTC at a distance of 420,038.5 km.

At 09:02 UTC, Europa moves behind Jupiter.  96 minutes later, at 10:38 UTC, Io moves behind Jupiter.  At 12:46 UTC, Europa reappears from behind Jupiter's shadow, and 32 minutes later (at 13:18 UTC) Io reappears from behind Jupiter's shadow.  You can see that Io is catching up to Europa as it orbits Jupiter faster than Europa.

From 01:03 to 01:13 UTC, Io occults Europa.  This is a 10.2 minute event with an impact parameter of 0.278 arc seconds.  This means that the centers of the two bodies are 0.278 arc seconds apart.  The smaller this number, the more total the occultation.  Europa and Io are 75.6 arc seconds from Jupiter at the time of this event, which is a great distance for viewing.  From 01:53 to 02:06 UTC, Io eclipses Europa.  This is a 12.5 minute event with an impact parameter of 0.370 arc seconds.  A nice eclipse.  Then when Io and Europa have moves behind Jupiter, Io once again eclipses Europa from 15:18 to 15:56 UTC.  This is a nice long 38.9 minute event with an impact parameter of 0.707.  So not a very deep eclipse but still worth viewing and measuring if possible.

Here are the orbital ribbons for today:

At 0h UTC today, Jupiter has an RA of 10h 01m 0.3s, and a DEC of +13d 03m 14.5s.  The phase angle today is 3.445 degrees, which is 0.134 degrees less than what it was yesterday.  The angular separation between Jupiter and the Sun as seen from Earth is 18.582 degrees, which is 0.744 degrees less than what it was yesterday.  The distance between Jupiter and the Sub is 805,129,106km, which is 37,680km further away than yesterday.  This gives a radial velocity between Jupiter and the Sun of 1,570 km/h, which is 4.167 km/h slower than what it was yesterday.  The distance between Jupiter and the Earth today is 947,585,803 km, which is 775,650 km further away than yesterday.  This gives a radial velocity between Jupiter and Earth of 32,318.75 km/h, which is 1,208.625 km/h slower than what it was yesterday.

Intense motion all the time.  Can you feel it?

Even though Jupiter is near Superior Conjunction (taking place on 26 August 2015), please send me your pictures of Jupiter!  If you do, I'll post them to this blog!  Please also include the time (in UTC if possible) you took the image, the telescope you used, the camera you used, and any other information you might think is useful.

Spread the word about this daily blog!  This blog is subject to evolution.  What can I do to make this blog more interesting and more informative?

Please send me your feedback, comments, and questions to jupitertoday AT gmail DOT com.

With my gratitude, the data used to create the orbit plots and ribbons was supplied by the JPL Horizons website.  The graphics showing the location of the four moons as seen from Earth are via 'Jupiter Viewer 2.8'.  Jupiter-Satellite and Satellite mutual events data is supplied from IMCEE.

Until tomorrow, I bid you Peace.

JUPITER TODAY | 01 August 2015 | Everyone West

Hello!

I hope everyone was able to go out and see a fairly rare "Blue Moon" today.  A Blue Moon is simply the 2nd full moon in a month.  Any month can have a Blue Moon except February.

We start today with the overall view of activity with the Jupiter system, showing the orbits of the four Galilean moons:

The Jupiter System 01 August 2015

This is a view of the Jupiter system looking down on it.  The blue line is the line of sight to Earth, while the gray line is the line of sight to the Sun.  The orbits of the four Galilean moons are shown.  The large dots indicate the position of each moon at 0h, 6h, 12h, 18h, and 24h (0h the next day) UTC for this date.  From this point of view, the moons revolve around Jupiter in a counter-clockwise motion.  For more information about this graphic, see the post from 30 July 2015.

At 0h UTC, Io begins the day in quad 1 moving east towards eastern elongation.  Europa and Ganymede start the day in quad 3 moving west.  Callisto will spend all day in quad 4 moving east.

By 6h UTC, Io has passed its eastern elongation and is now in quad 2 moving west.

At 12h UTC, Io has begun its transit of Jupiter moving into quad 3, and Europa is very near its western elongation.

By 18h UTC, Io is firmly in quad 3 moving west.  Europa is just past its western elongation and is now in quad 4 moving east.

At 0h UTC tomorrow, Io is very near its western elongation moving into quad 4.  Europa is now firmly in quad 4 moving east.

Io moves through an apojove (the furthest away it will be from Jupiter in this orbit) at 15:50 UTC at a distance of 423,493.426 km.

Io is the only moon interacting with Jupiter from our point of view today.  Io transits Jupiter from 13:21 to 15:39 UTC, and Io's shadow transits Jupiter from 13:46 to 16:04 UTC.

There is one satellite mutual event and it's sort of a strange one.  The shadow of Ganymede casts its shadow upon Europa.  The strange part is that just the smallest of slivers of the shadow are actually falling on Europa.  So I'd call this a "grazing eclipse" in the most extreme sense.  This 143.5 minute event goes from 02:09 to 04:32 UTC.  At that time, Europa is 102.48 arc seconds from Jupiter, and Ganymede and Europa are 7.7 arc seconds apart.

Here are the orbital ribbons for today.  I've included the location of Jupiter (the white dot in the center) as well as the orbit arcs of the four moons so you can better see where they are in relation to themselves and Jupiter.

IMO this is an extra pretty one today.

At 0h UTC, Jupiter has an RA of 10h 00m 11.4s, and a DEC of +13d 07m 36.0s.  The phase angle today is 3.579 degrees, which is 0.133 degress less than what it was yesterday.  The angle between Jupiter and the Sun as seen from Earth is 19.326 degrees, which is 0.745 degrees less than what it was yesterday.  The distance between Jupiter and the Sun is 805,091,426 km which is 37,780 km greater than what it was yesterday.  This gives a radial velocity between Jupiter and the Sun of 1,574.167 km/h (moving away from one another), which is 7.791 km/h slower than what it was yesterday.  The distance between Jupiter and the Earth is 946,810,153 km, which is 804,657 km greater than what it was yesterday.  This gives a radial velocity of 33,527.375 km/h (moving away from one another), which is 1,208.167 km/h slower than what it was yesterday.

Even though Jupiter is near Superior Conjunction (taking place on 26 August 2015), please send me your pictures of Jupiter!  If you do, I'll post them to this blog!  Please also include the time (in UTC if possible) you took the image, the telescope you used, the camera you used, and any other information you might think is useful.

Spread the word about this daily blog!  This blog is subject to evolution.  What can I do to make this blog more interesting and more informative?

Please send me your feedback, comments, and questions to jupitertoday AT gmail DOT com.

With my gratitude, the data used to create the orbit plots and ribbons was supplied by the JPL Horizons website.  The graphics showing the location of the four moons as seen from Earth are via 'Jupiter Viewer 2.8'.  Jupiter-Satellite and Satellite mutual events data is supplied from IMCEE.

Until tomorrow, I bid you Peace.

JUPITER TODAY: 31 July 2015 | Three Perijoves

Good Day!

JUPITER TODAY is a daily blog about the dynamic Jupiter system for the purpose of monitoring activity.

We start with the overall view of activity with the Jupiter system, showing the orbits of the four Galilean moons:

Jupiter System 31 July 2015

This is a view of the Jupiter system looking down on it.  The blue line is the line of sight to Earth, while the gray line is the line of sight to the Sun.  The orbits of the four Galilean moons are shown.  The large dots indicate the position of each moon at 0h, 6h, 12h, 18h, and 24h (0h the next day) UTC for this date.  From this point of view, the moons revolve around Jupiter in a counter-clockwise motion.  For more information about this graphic, see the post from 30 July 2015.

Jupiter System Earth POV 0h UTC

At 0h UTC, Io begins the day in quad 3 moving west.  Europa starts the day in quad 2 moving west.  Ganymede is also in quad 2 moving west and will be transiting Jupiter today.  Callisto begins the day in quad 3 moving west and will be going through its western elongation today.

Jupiter System Earth POV 6h UTC

By 6h UTC, Io is very near its eastern elongation and will be moving into quad 4 heading east.  Europa and Ganymede continue in quad 2 moving towards transit.  Callisto is still in quad 3 moving west.

Jupiter System Earth POV 12h UTC

At 12h UTC, Io is now firmly in quad 4 moving east.  Europa is in quad 2 near transit.  Ganymede is transiting Jupiter.

Jupiter System Earth POV 18h UTC

By 18h UTC, Io is moving behind Jupiter and into quad 1 heading east.  Europa and Ganymede have both transited Jupiter and are now in quad 3 moving west.  Callisto has moved past its western elongation and is now in quad 4 heading east.

Ganymede is at perijove at 01:00 UTC at a distance of 1,069,228.534 km.  Europa is at perijove at 18:40 UTC at a distance of 664,487.055 km.  Io moves through perijove at 18:45 UTC at a distance of 420,023.696 km.  Notice again that the perijoves of Europa and Io are at the same time on opposite sides of Jupiter.

Quite a few Jupiter-Satellite events today.  From 11:09 UTC to 14:47 UTC, Ganymede transits Jupiter.  Ganymede's shadow transits Jupiter from 12:54 UTC to 16:29 UTC.  From 14:28 UTC to 17:20 UTC, Europa transits Jupiter.  This means that from 14:28 UTC to 14:47 UTC, Ganymede and Europa are both seen transiting Jupiter.  The shadow of Europa transits Jupiter from 15:18 UTC to 18:09 UTC.  Io moves behind Jupiter at 16:07 UTC.  Finally, Io reappears from Jupiter's shadow at 18:50 UTC.

There are no satellite mutual events today.

Here are the orbital ribbons for today:

Orbital Ribbons 31 July 2015

Jupiter RA 09h 59m 22.6s, DEC +13d 11m 56.4s.  The phase angle today is 3.712 degrees, which is 0.132 degrees less than what it was yesterday.  The angular separation between the Sun and Jupiter as seen from Earth is 20.071 degrees, which is 0.745 degrees less than what it was yesterday.  The distance between Jupiter and the Sun is 805,053,646 km, which is 37,967 km further away than what is was yesterday.  This gives a radial velocity of Jupiter relative to the Sun of 1,581.958 km/h moving away.  The distance between Jupiter and Earth today is 946,005,496 km.  That's 833,653 km further away than yesterday, which translates into a radial velocity of 34,735.542 km/h moving away from one another.

Did you have any idea we were moving so much and so quickly?

Even though Jupiter is near Superior Conjunction (taking place on 26 August 2015), please send me your pictures of Jupiter!  If you do, I'll post them to this blog!  Please also include the time (in UTC if possible) you took the image, the telescope you used, the camera you used, and any other information you might think is useful.

Spread the word about this daily blog!  This blog is subject to evolution.  What can I do to make this blog more interesting and more informative?

Please send me your feedback, comments, and questions to jupitertoday AT gmail DOT com.

With my gratitude, the data used to create the orbit plots and ribbons was supplied by the JPL Horizons website.  The graphics showing the location of the four moons as seen from Earth are via 'Jupiter Viewer 2.8'.  Jupiter-Satellite and Satellite mutual events data is supplied from IMCEE.

Until tomorrow, I bid you Peace.

JUPITER TODAY: Restart on 30 July 2015

At long last, I'm restarting my daily post of 'Jupiter Today'.  What stopped me before was the large amount of time it took to create the graphics and then record, render, and upload the audio and video to youtube.  So now this daily update will be done on this blog, along with other topics that catch my curiosity.

We start with the overall view of activity with the Jupiter system, showing the orbits of the four Galilean moons:

Jupiter System Activity 30 July 2015

This is a view of the Jupiter system looking down on it.  The blue line is the line of sight to Earth, while the gray line is the line of sight to the Sun.  The orbits of the four Galilean moons are shown.  The large dots indicate the position of each moon at 0h, 6h, 12h, 18h, and 24h (0h the next day) UTC for this date.  The moons revolve around Jupiter in a counter-clockwise motion.  I've divided the system up into four quadrants marked by the sun lines.  When a moon is in Quadrant 1, it appears to be moving east from Earth's point of view.  A quadrant 1 moon is also on the far side of Jupiter as seen from Earth.  When a moon is in Quadrant 2, it has moved past its eastern elongation and now appears to be moving west.  A quadrant 2 moon is on the near side of Jupiter as seen from Earth.  When a moon is in Quadrant 3, it has transited Jupiter and is still moving west as seen from Earth.  A quadrant 3 moon is on the near side of Jupiter.  When a moon is in Quadrant 4, it has passed its western elongation and is now moving east as seen from Earth.  A quadrant 4 moon is on the far side of Jupiter.

Jupiter system at 0h UTC

At 0h UTC, Io begins the day in quadrant 1 heading east.  Europa is also in quadrant 1 heading east appearing to be very close to Io.  Ganymede is in quadrant 2 heading west, having just past its eastern elongation.  Callisto is in quadrant 3 heading west all day today towards is western elongation which will take place tomorrow.

Jupiter System at 6h UTC

By 6h UTC, Io and Europa are still in quad 1 heading east.  Ganymede is now firmly in quad 2 heading west, and Callisto continues is quad 3 slowly moving west.

Jupiter system at 12h UTC

By 12h UTC, Io has passed its eastern elongation and is now in quad 2 heading west.  Europa, Ganymede, and Callisto continue their orbits in the same quadrants.

Jupiter system at 18h UTC

By 18h UTC, Io has begun its transit of Jupiter and move into quad 3 moving west.  Europa is near its eastern elongation and will be moving into quad 2 moving west.

Jupiter System 0h UTC 31 July 2015

And finally by 0h UTC tomorrow, Io has successfully transited Jupiter and is now firmly in quad 3 heading west.  Europa is past its eastern elongation and is now firmly in quad 2 moving west.  Ganymede continues moving west in quad 2.  Callisto is in quad 3 also moving west.

So by the end of the day, all four Galilean moons are moving west.

Europa is at apojove (the furthest it will be from Jupiter in this orbit) at 00:24 UTC at a distance of 667,652.7 km.  Io is at perijove (the closest it will be to Jupiter in this orbit) at 00:25 UTC at a distance of 420,036.9 km.  Io is at apojove at 21:29 UTC at a distance of 423,493.8 km.  Notice how close in time and space Europa's apojove and Io's perijove are.

There are three Jupiter-Satellite events today.  At 00:21 UTC, Io reappears from Jupiter's shadow.  Io transits Jupiter from 18:50UTC to 21:09UTC.  The shadow of Io transits Jupiter from 19:17UTC to 21:35UTC.

There are no satellite mutual events today.

Lastly are what I call "Orbital Ribbons", which are the spacial and temporal connections/relationships between the four Galilean moons.  They're usually very pretty.

Orbital Ribbons 30 July 2015

Jupiter RA 09h 58m 33.9s DEC +13d 16m 15.6s.  The phase angle (the angle between the Earth and the Sun as seen from Jupiter) is 3.844 degrees.  The angular separation between Jupiter and the Sun as seen from Earth is 20.816 degrees.  The Jupiter-Sun distance today is 805,015,679 km.  The Jupiter-Earth distance today is 945,171,843 km.

Please send me your pictures of Jupiter!  If you do, I'll post them to this blog!  Please also include the time (in UTC if possible) you took the image, the telescope you used, the camera you used, and any other information you might think is useful.

Also spread the word about this daily blog!  This blog is subject to evolution.  What can I do to make this blog more interesting and more informative?

Please send me your feedback, comments, and questions to jupitertoday AT gmail DOT com.

With my gratitude, the data used to create the orbit plots and ribbons was supplied by the JPL Horizons website.  The graphics showing the location of the four moons as seen from Earth are via 'Jupiter Viewer 2.8'.  Jupiter-Satellite and Satellite mutual events data is supplied from IMCEE.

Until tomorrow, I bid you Peace.