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:
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| The Jupiter System 01 August 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.
