Jupiter - GRS transit and Europa + shadow

[ausastronomer (John Bambury)]

For those interested the GRS has just started to transit the planets disk. Europa and its shadow will transit the planets disk commencing at about midnite. Skies are ok for planetary with high thin cloud but seeing is pretty bad at the moment, just hoping it settles in the next hour or 2.

CS-John B

Not much chop here, have 6/8 cirrus and altocumulus plus 10kts wind. Oh well a normal time to bed wont hurt occasionally.
Thanks for the information. Would have been nice to have another go, but it will come again.

[MiG]

How do you know what cloud cover you have? By observation? I imagine that would only work when the moon is out.

Aviation METARS are handy for lower level info, but on stations with automated cloud reporting, clouds above 12,500 feet aren't reported due to measurement limits. Clear sky below FL125 results in CAVOK (Cloud and Visibility OK) even if there are clouds up higher.

As part of my training for my job in Flight Service, I had to learn how to be a Met observer, and it has come in very handy over the years. The moon certainly illuminates the sky, but so do the stars, light pollution etc. You definitely need to let your eyes adapt to the the dark as well.

Peter