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.