Great resource for identifying & predicting (the main) moons of Saturn & Jupiter

[StarGazingSiouxsie]

Hello

Some people may already know about this site but for those that don't (which included me half an hour ago) I can highly recommend it.

I asked someone how they were able to identify which moon was which in their eyepiece and they pointed me to this site. You can select any time / date you wish so that you can plan your observing if you want to see a particular transit or moon's shadow. 

(Jupiter's moons page at bottom left of the page linked to)

https://shallowsky.com/satsat/

 

Siouxsie 

 

[John]

If you observe Jupiter's Galilean moons really carefully at high magnifications you can make out that they have different disk sizes. It's fun to try and work out which might be which from observing them and then to use a tool such as the one linked to above to see if you got it right

[StarGazingSiouxsie]

5 minutes ago, John said:

If you observe Jupiter's Galilean moons really carefully at high magnifications you can make out that they have different disk sizes. It's fun to try and work out which might be which from observing them and then to use a tool such as the one linked to above to see if you got it right

Yes! And Io has that slighty burnt pizza topping surface,. which, whilst not really discernable through an eyepiece, given nice viewing conditions one can make a slightly orange tinge to it, like Mars had a baby and it ran off to Jupiter. I noticed this the other night, I checked and I was correct, it was Io! 1 in 4 chance, I know, but I'll take that  

Edited August 16, 2020 by StarGazingSiouxsie

[markse68]

I can usually tell Ganymede as it’s obviously bigger but the other 3 seem much of a muchness so far- need to hone my disk sizing skills 

[John]

18 hours ago, StarGazingSiouxsie said:

Yes! And Io has that slighty burnt pizza topping surface,. which, whilst not really discernable through an eyepiece, given nice viewing conditions one can make a slightly orange tinge to it, like Mars had a baby and it ran off to Jupiter. I noticed this the other night, I checked and I was correct, it was Io! 1 in 4 chance, I know, but I'll take that  

My point was serious - you really can tell the difference in their disk sizes with some practice and it does not take a hugely powerful scope to do this. I've yet to see any markings on the Galilean moons but I know that one or two observers on this forum have see vague details on Ganymede's disk.

 

[StarGazingSiouxsie]

1 hour ago, John said:

My point was serious - you really can tell the difference in their disk sizes with some practice and it does not take a hugely powerful scope to do this. I've yet to see any markings on the Galilean moons but I know that one or two observers on this forum have see vague details on Ganymede's disk.

 

Oh, I know, I wasn't taking the ***s. Just being happy  

[John]

10 minutes ago, StarGazingSiouxsie said:

Oh, I know, I wasn't taking the ***s. Just being happy  

Well that's OK then !

[Geoff Barnes]

Don't be confused @StarGazingSiouxsie, he's really a lovely old thing, like everyones favorite uncle and happy for you!

( Strange English humour you know)! 😂

Edited August 18, 2020 by Geoff Barnes