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.