GRS Transit

[TheDecepticon]

Howdy. My time is 8.40 pm. Is there a GRS transit over the next couple of hours and is it near Ganymede's shadow? I have 2 pieces of software that are telling conflicting stories. One is Jupiter2 and the other is Starry Night. Starry Night is more accurate.:shrug:

[mozzie]

i have starry night and if your settings are all correct then starry night will be correct
mozzie

[erick]

The difference could be the parameter that determines whether it is allowing for the time of light travel to the Earth or not (around 40-50 minutes, I think, depending on where the two planets are in their respective orbits). I know Stellarium has such a parameter.


Given we are always observing from the Earth, I don't quite know why we would need such a parameter anyway?

[erick]

I've just had a look. My Stellarium and my Jupiter2 agree on moon positions but seem to be about 40-50 minutes different on GRS position. Strange. I must check them both against reality one night. I know Stellarium seemed about right on "real" GRS position last time I compared.

[mozzie]

erick i checked it with my starry night and the eyepiece and it was accurate
mozzie

[erick]

Thanks, I will have to do the same with Stellarium and Jupiter2