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The recent total eclipse, got me thinking about how it would look in my world.

I have a earth-sized planet with a ring system, a couple of small moons and 1 or 2 bigger moons.

How would a planetary ring system affect the viewing of the total eclipse of any one of these moons:

  • as seen from the planet surface?
  • bonus - as seen from the ISS position?

I'm thinking there must be some interference of some sort:

  • Would the position of the rings affect the light refractions, flares etc?
  • would the reflection of the rings light up the planet facing side of the moon?
  • Would there be absolutely no difference to what we saw recently?

I'm not looking for an artistist depiction (although if you have any handy graphics, please feel free to share) but a basic written description of the sort of differences one would see.

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  • $\begingroup$ I know that we have a question around here somewhere, from way back in the beta, which is about what a ring system around Earth would look like from the ground. It had an answer with some really nice pictures for illustration, showing what something similar to Saturn's ring system around Earth might look like from different latitudes on the ground. I just can't find it! $\endgroup$ – a CVn Aug 23 '17 at 20:35
  • $\begingroup$ @MichaelKjörling, There is a video on youtube with something similar which I've linked in one of my previous questions regarding planetary rings. youtu.be/hoz5Q2rGQtQ $\endgroup$ – EveryBitHelps Aug 23 '17 at 20:44
  • $\begingroup$ Just found this link which has lots of good "earth with rings" information but nothing on eclipses. youtu.be/CItDiuBWP5I $\endgroup$ – EveryBitHelps Aug 23 '17 at 21:02
  • $\begingroup$ Nothing!!! usually it is the gas giant that comes with a ring system so unless you're floating high above the cloud whereby the air is less dense and opaque... as for the bonus question, it really depends on how dense and spread out the ring is. Since there is only a small region of shadow cast by the moon I'm running a simulation in my brain to compute all the possible sky views and render them in 8k for every angle of the ring plane... $\endgroup$ – user6760 Aug 24 '17 at 1:57
  • $\begingroup$ @user6760, yes it is usual for the gas giants to have the rings. My second link in the comments does discuss the feasibility of earth like planets with rings. However, that is not the question in this case. Regardless of if on a gas giant or rocky terrestrial planet, what would the total eclipse look like (in general) from the planet side of the rings...be it on the surface or mid atmosphere. $\endgroup$ – EveryBitHelps Aug 24 '17 at 13:29
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Since the availability of real photos are limited, I have taken a few screenshots from SpaceEngine, whose rendering and visualization I find to be pretty good.

Here is a shot of Titans shadow falling onto Saturn. Titan (just like the majority of Saturns moons) orbits within Saturns ring plane. The eclipse zone on the 'surface' of Saturn will most commonly lie along the intersection of Saturns orbital plane, and the ring plane, so the shadow will commonly lie across the rings as shown. The shadow from highly eccentric and/or remoter moons may miss the ring plane, as shown in the photo in the other answer.

Shadows commonly cross the ring plane From the surface of saturn, in the center of the shadow, it looks like this:

View from Saturn to Titan

I'm not entirely convinced SpaceEngine is rendering the occuluded glare around the sun correctly. The center of the shadow is a tiny bit above the ring plane in the first screenshot, but in the second, the eclipse seems visible from much higher latitude. I think this is a more realistic visualization of the ring illumination when located at the center of the shadow, but of curse, the sun glare here should be obscured:

https://i.imgur.com/sBVQL9t.jpg

If I move the camera further out, inside the shadow cone, towards Titan, I need to be far beyhond the rings before titan fully eclipses the sun in SpaceEngine. I don't know what the relative size of Titan and the Sun are from Saturns surface, but it should be easy enough to calculate.

Alternative viewpoint

Here is a dramatic shot taken from a higher latitude, a bit outside the zone of totality:

Outside totality

And a shot from close to the pole, with Titans position marked:

Polar shot

Screenshots are taken from the free http://spaceengine.org program. Titans shadow on Saturns rings is one of the preset scenarios if you want to explore some more.

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  • $\begingroup$ Thank you so much! When I have chance I will definitely be playing around with this! $\endgroup$ – EveryBitHelps Sep 3 '17 at 20:38
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First of all, realize that the rings themselves cast their own shadow on the planet. Here is a photo of Saturn during a time that the sun is at a rather oblique angle.

enter image description here

If you live in those shadows the sun appears obscured by the rings. The shadows are constant, but the effects at any one spot on the planet within tens of degrees of latitude (depending on the tilt) are going to be a seasonal occurrence. By that, I mean that the shadow starts as a rather fine line (as wide as the ring system) at the equator, sweeps northward to a northernmost position then back southward through the equator to a southern most position and then back to the equator again all within the period of one of the planet's years.

In this photo, a moon (I'm not sure which) is in the foreground but the sun is too oblique for it to cast a shadow on the planet.

Here is another photo with more direct (less oblique) sunlight:

enter image description here

In this photo, you can clearly see there is a shadow from a moon. If you were in that shadow you would, of course, experience an eclipse, but it is outside the shadow of the rings because the moon is quite a way outside the ring system, and hence there is no interaction of rings with the eclipse because they are in different parts of the sky.

Now, there are moons that are within the ring system, or rather their orbits lie within gaps in the ring system. There could be times where the sun is obscured by both a moon and rings at the same time. Certainly, there would be an opportunity for some very spectacular eclipses.

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