Shadow on Jupiter.

[cotterless45]

Usually I see a moon and it's shadow. Tonight, just caught a shadow to the edge, then the moon appeared. Using a 150pl (hurrah)and 12mm NLV,Nick.

Sorry the drawing's not up to much, the amont of detail to the belts was amazing.

[LukeSkywatcher]

So according to your drawing................the shadow appeared an hour before you saw the moon?

I'm thinking that is a bit strange.

[Qualia]

Maybe Io it was hidden by cloud.

[Jim-a]

There was quite a gap between the shadow hitting the edge and Io appearing - guess must have been the relative position of the sun and where it was casting the shadow? My sketch at a similar time to coterless's show same positioning

[earth titan]

Good conditions tonight. Pushing near on x400 on the c9.25 and still passable. Best at x250 with my 9mm Ortho.

Have to say I saw no shadow. What time was it that you were viewing? I saw IO leave the planets disc so you guys must have been out early!

Typed by me on my fone, using fumms... Excuse eny speling errurs.

[LukeSkywatcher]

There was quite a gap between the shadow hitting the edge and Io appearing - guess must have been the relative position of the sun and where it was casting the shadow? My sketch at a similar time to coterless's show same positioning

I tend to agree. It must have been the relative position of the Sun to the planet. Maybe even a stubborn cloud covering the Jovian moon for an hour.

[John]

The shadows are quite easy to see against the Jovian cloud tops. The moons disks themselves, as they pass in front of the planet, somewhat harder.

The angle of illumination can cause the moon shadow to be still on the disk when the moon itself is visible against the sky having left the disk and, vice versa, the shadow is sometimes the first to leave the Jovian disk.

This little Sky & Telescope Java applet tells you what is going on, on and around Jupiter:

http://www.skyandtel...ascript/jupiter

[tich]

I was seeing a shadow too although by the time I started to image the shadow had gone, if only I'd plugged in the Philips webcam first instead of messing around with the QHY5-II I might have captured it.

[cotterless45]

Many thanks for posting the Sky and Telescope link, I've book marked it.

Must of been Io itself right on the rim, usually see moon shadow when they're passing away from the disc. This is the first one that I saw the moon face on the surface. Seeing conditons were ace.At x200 the relative sizes of the moons could be picked out,

Nick.

[earth titan]

Ahhh. Coffee and some time to check timings!

Crikey you chaps were out early. I just caught IO leaving the disc but I did spend a bit of time messing about with guiding / collimation. Shame cos I enjoy watching transits. Should have checked transit times before I went out.

Typed by me on my fone, using fumms... Excuse eny speling errurs.