Jupiter double transit

Jupiter 2016-Mar-8

2016 March 8 at 00.40 UT  x260.  N is at the bottom.

When transits happen on the same day that Jupiter is at opposition, we see the disk and shadow of the satellite in question overlap. An hour or two before this double transit the sky was promisingly clear and starry. Then Murphy’s Law struck – right about the time Europa started its transit at 23.10 the cloud arrived.  The drawing above shows the situation 90 minutes later at about 00.40, with Europa (dark, against the bright disk) half way in its path across the face the planet, and Io (bright, against the dusky limb) just starting to transit.  I was watching through cloud which degraded the view enough to prevent me seeing the disk/shadow overlap.