Jupiter double-double shadow transit 23 Dec and 30 Dec 2023

[Paz]

A double shadow transit of Ganymede and Europa is coming twice for Christmas, and both events are at fairly civilised times...

23rd December both shadows on at around 17.24 - 17.40 (just eyeballing Sky Safari and allowing for light time).

30th December both shadows on at around 22.15 - 23.40.

I've not done a double shadow transit before, I hope the shadows will be noticeably different sizes, but mostly I hope it's not cloudy.

[dweller25]

Thanks for the heads up 👍

[Stu]

8 hours ago, Paz said:

(just eyeballing Sky Safari and allowing for light time).

There is an option in SkySafari to allow for light travel time. It’s in the Precession menu. Makes life much easier 👍

[fifeskies]

Using both Galilean Moons of Jupiter (shallowsky.com) and Stellarium which does simulate shadow transits if you zoom in , I get a different time for these transits

December 23rd

double shadow begins at 19:09

 

According to the graphical simulation in Stellarium , the shadow of Ganymede is unfortunately very close to the pole and will be difficult to make out aginst the dark clouds being rather elongated into an elipse.

The shadow of Europa however should be nice and clear much closer to the middle of the disk., and is against a lighter cloud region so stands out better.

Jupiter is around 45 degree altitude for the event (for me) so higher up in less wobbly air for most of the UK.

 

and for the 30th December

Double shadow begins at 21:45

 

 

Again there is one shadow close to the pole against darker cloud , and the second shadow (Europa) will show against lighter cloud bands.

This event happens while Jupiter is at a lowish altitude when viewed from UK (alt 35 degree for me).

This means the clarity will be poorer than for the 23rd event which is when Jupiter is  higher in the sky and so should be in clearer air.

 

 

Just need those pesky clouds to stay away.

 

 

Below is an image I took of 1st December 2023 of a shadow transit (Io)

Seeing was poor but you can make out the shadow , the red spot to the right of it , and the moon just exiting from the transit across the face of Jupiter to the right of that.

Edited December 8, 2023 by fifeskies

[JOC]

So what is the upshot here - If clear I was going to set-up to have a look between 5pm and 6pm will I be able to see a double shadow transit - if not I won't bother 'cos it will be cold.

[johnturley]

1 hour ago, JOC said:

So what is the upshot here - If clear I was going to set-up to have a look between 5pm and 6pm will I be able to see a double shadow transit - if not I won't bother 'cos it will be cold.

Unfortunately not much chance of it being clear on 23rd December for most of the UK.

John 

[wookie1965]

Every astronomy event this year has been clouded out as far as I can remember. I have not seen one meteor shower this year. 

[Stu]

On 24/12/2023 at 08:34, wookie1965 said:

Every astronomy event this year has been clouded out as far as I can remember. I have not seen one meteor shower this year. 

It’s been rubbish I agree, but fingers crossed for 30th. Will be interesting to see which timings turn out to be correct, if we do get to see it 🤞

[wookie1965]

14 hours ago, Stu said:

It’s been rubbish I agree, but fingers crossed for 30th. Will be interesting to see which timings turn out to be correct, if we do get to see it 🤞

According to the BBC weather app forecast is light rain showers the next clear spell is Tuesday the 9th from 5pm until 10pm 

[PeterStudz]

Chucking it down here with heavy rain forecast throughout the night. Howling wind too. For me I think the chance of seeing this tonight is zero ☹️ 

[Stu]

No hope here either, blowing a gale and chucking it down all afternoon and evening ☹️

[Captain Scarlet]

Likewise. Big storm just building up this afternoon peaking tomorrow.