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Old 31-01-2018, 08:11 PM
bigjoe (JOSEPH)
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Join Date: Nov 2010
Location: sydney
Posts: 1,363
Transit of Io across Jupiters face...Feb 2nd

There will be another transit of Io, Jupiters second brightest, and third largest Moon as viewed from Earth.

At currently just under 1".. you'd need at least a 5 inch plus scope ..preferably a 6 , high power and good seeing to actually resolve it as a disk, and not mag the airy...see Rayleighs and Dawes for your size scope. Ganymede for instance reaches over 1.5" at some apparitions.

Transit is due to commence in Oz
Feb 2 at 00.37am EST...there will also be its shadow transit at 01.33am EST.

Currently at Mag 5.9, Io is the second brightest after Ganymede at 5.5.

Europa, Callisto, and then Ganymede will be further away from Jupiter in that order at that time.

At 5.4 AU , Jupiter at currently 34" and its moons, will appear much bigger soon, when reaching around 5AU when Jupiter will be 40.8" on 15th March.

Of course there may be clouds, as we are currently experiencing around some of NSW and elsewhere , for tonights Lunar Eclipse ...Lets hope not.
PS: Times ..you need to adjust for daylight saving.

bigjoe.

Last edited by bigjoe; 31-01-2018 at 08:22 PM. Reason: Adding
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