Gas Giants and a Vanishing/Reappearing Moon

[PeterStudz]

Southampton back garden 09/09/23 - 10/09/23. Skywatcher 200p Dob on DIY EQ platform.

Had a nice little 2.5 hour session with my daughter on Saturday night - Sunday morning observing Saturn, Neptune, Jupiter and Uranus.

Seeing was good although not quite as good as the night before. Transparency was average. Might have been due to hazy cloud or dust. Colours weren’t as clear as they could be with a slight yellow/brown tint.

Saturn - Could make out subtle cloud banding, three moons and the Cassini Divison at the tips. At times it could take x240 before things started to get fuzzy.

Neptune - First time Alice has seen Neptune (I’ve only seen it a few times) and of course whatever you do it’s still a very little blue dot even at x240. Although when you know what you are looking at… And even if tiny it’s obviously not a star.

Uranus - a light pastel blue slightly bigger dot. I enjoy observing this and we both tried to spot a moon(s) but no joy here.

Jupiter - a favourite of my daughters. The GRS was in view and there was considerable detail in the banding and around the GRS. Although a little washed out and not quite as good as the previous night. There was a “missing” moon and a quick look at a simple phone app appropriately called “Gas Giants” showed that Europa was being eclipsed by Jupiter’s shadow. We observed Jupiter for some time and the views improved as it got higher. Again, x240 possible and it was still sharp. Then, a surprise - In a split second Europa became visible again just before it traveled behind the disc! I’ve never seen this before and had assumed that Europa would not be visible again until it got to the other side of Jupiter.

To illustrated what I mean I’ve created a little GIF from the Gas Giant app. I guess it’s all down to angles, where the sun is and relative positions. At this point Europa was very bright and “kissing” Jupiters limb. It only lasted around 4 mins before the moon disappeared behind the planet. I also just had time to take a short smartphone video and create this image using the smartphone app “VideoStack”. A sketch would have been ideal by I’m useless at sketching. And although it doesn’t do it justice it does give a reasonable idea of what we could see at the eyepiece. Europa, the tiny dot bottom left against the limb. GRS near the limb. It’s even starting to pick out some ovals in the Southern Hemisphere.

A good end to an excellent night.

 

 

Edited September 10, 2023 by PeterStudz

[IB20]

44 minutes ago, PeterStudz said:

Southampton back garden 09/09/23 - 10/09/23. Skywatcher 200p Dob on DIY EQ platform.

Had a nice little 2.5 hour session with my daughter on Saturday night - Sunday morning observing Saturn, Neptune, Jupiter and Uranus.

Seeing was good although not quite as good as the night before. Transparency was average. Might have been due to hazy cloud or dust. Colours weren’t as clear as they could be with a slight yellow/brown tint.

Saturn - Could make out subtle cloud banding, three moons and the Cassini Divison at the tips. At times it could take x240 before things started to get fuzzy.

Neptune - First time Alice has seen Neptune (I’ve only seen it a few times) and of course whatever you do it’s still a very little blue dot even at x240. Although when you know what you are looking at… And even if tiny it’s obviously not a star.

Uranus - a light pastel blue slightly bigger dot. I enjoy observing this and we both tried to spot a moon(s) but no joy here.

Jupiter - a favourite of my daughters. The GRS was in view and there was considerable detail in the banding and around the GRS. Although a little washed out and not quite as good as the previous night. There was a “missing” moon and a quick look at a simple phone app appropriately called “Gas Giants” showed that Europa was being eclipsed by Jupiter’s shadow. We observed Jupiter for some time and the views improved as it got higher. Again, x240 possible and it was still sharp. Then, a surprise - In a split second Europa became visible again just before it traveled behind the disc! I’ve never seen this before and had assumed that Europa would not be visible again until it got to the other side of Jupiter.

To illustrated what I mean I’ve created a little GIF from the Gas Giant app. I guess it’s all down to angles, where the sun is and relative positions. At this point Europa was very bright and “kissing” Jupiters limb. It only lasted around 4 mins before the moon disappeared behind the planet. I also just had time to take a short smartphone video and create this image using the smartphone app “VideoStack”. A sketch would have been ideal by I’m useless at sketching. And although it doesn’t do it justice it does give a reasonable idea of what we could see at the eyepiece. Europa, the tiny dot bottom left against the limb. GRS near the limb. It’s even starting to pick out some ovals in the Southern Hemisphere.

A good end to an excellent night.

 

 

I thought I was going mad when I saw 4 moons then only 3. It didn’t even occur to me about the planetary shadow as it was quite far away from the limb.

[bosun21]

50 minutes ago, PeterStudz said:

Southampton back garden 09/09/23 - 10/09/23. Skywatcher 200p Dob on DIY EQ platform.

Had a nice little 2.5 hour session with my daughter on Saturday night - Sunday morning observing Saturn, Neptune, Jupiter and Uranus.

Seeing was good although not quite as good as the night before. Transparency was average. Might have been due to hazy cloud or dust. Colours weren’t as clear as they could be with a slight yellow/brown tint.

Saturn - Could make out subtle cloud banding, three moons and the Cassini Divison at the tips. At times it could take x240 before things started to get fuzzy.

Neptune - First time Alice has seen Neptune (I’ve only seen it a few times) and of course whatever you do it’s still a very little blue dot even at x240. Although when you know what you are looking at… And even if tiny it’s obviously not a star.

Uranus - a light pastel blue slightly bigger dot. I enjoy observing this and we both tried to spot a moon(s) but no joy here.

Jupiter - a favourite of my daughters. The GRS was in view and there was considerable detail in the banding and around the GRS. Although a little washed out and not quite as good as the previous night. There was a “missing” moon and a quick look at a simple phone app appropriately called “Gas Giants” showed that Europa was being eclipsed by Jupiter’s shadow. We observed Jupiter for some time and the views improved as it got higher. Again, x240 possible and it was still sharp. Then, a surprise - In a split second Europa became visible again just before it traveled behind the disc! I’ve never seen this before and had assumed that Europa would not be visible again until it got to the other side of Jupiter.

To illustrated what I mean I’ve created a little GIF from the Gas Giant app. I guess it’s all down to angles, where the sun is and relative positions. At this point Europa was very bright and “kissing” Jupiters limb. It only lasted around 4 mins before the moon disappeared behind the planet. I also just had time to take a short smartphone video and create this image using the smartphone app “VideoStack”. A sketch would have been ideal by I’m useless at sketching. And although it doesn’t do it justice it does give a reasonable idea of what we could see at the eyepiece. Europa, the tiny dot bottom left against the limb. GRS near the limb. It’s even starting to pick out some ovals in the Southern Hemisphere.

A good end to an excellent night.

 

 

Great report Peter👍.

[PeterStudz]

17 minutes ago, IB20 said:

I thought I was going mad when I saw 4 moons then only 3. It didn’t even occur to me about the planetary shadow as it was quite far away from the limb.

We missed that bit. But seeing only three moons I assumed that one must be behind Jupiter. It was only when Europa pooped out of seemingly nowhere that I looked it up. It’s really nice when you get a surprise like this!

[Mandy D]

@PeterStudz it's an interesting phenomonon. I've never seen it and it looks like I got up too late, anyway, but I did grab a couple of images that has the moons in a nice arrangement.

https://stargazerslounge.com/topic/413587-jupiter-europa-io-callisto-ganymede/

It must have been realy cool to see.

[Epick Crom]

Great report Peter and nice you caught a reappearance of Europa from an eclipse. I've never seen an eclipse or a reappearance of a Galilean moon, must have been fantastic!

 

Clear Skies

Joe