Celestia Forums

I noticed that Pandora (a small moon or large asteroid orbiting Saturn) on May 13, 1676 goes from lit (13:04:39:27) to full immersion (completely in Saturn's shadow) (13:04:40:05) and only approaches Saturn's shadow upon its rings six seconds later (13:04:46:08), although Pandora appears to be in the same plane as the rings. Can anyone explain that?

This is caused by the fact that Celestia's shadowing does not take into account the oblateness of the planet. If you change Saturn to a perfectly spherical planet, Pandora will go into darkness at the correct time. On the other hand, the ring shadowing does take into account planet oblateness.

I created a "blimp" to orbit Saturn and exaggerated the planet's oblateness to show this visually.

that is one very wide saturn

Added after 47 seconds:

Sirius_Alpha wrote:I created a "blimp" to orbit Saturn and exaggerated the planet's oblateness to show this visually.

celestia DEVs really need to fix this, so celestia takes the oblateness into account when rendering shadows

I see. Well, it just seemed to me that Celestia is an excellent product and very near being what, say, a NASA engineer might consider as a high precision tool, if youze guyz want to press on to that level of excellence. And thank you for your very informative and knowledgeable explanation. Regards.

Added after 9 hours 7 minutes:
Very good explanation, Sirius_Alpha. I'm impressed by how active, helpful and knowledgeable Celestia forum posters are. I've run poor SevenSpheres pretty ragged. Shall I submit trappistplanets' fix suggestion to 'DEV ideas' or to 'BUGS' or to GitHub? Still learning the etiquette here. Apologies.

TJackson wrote:Shall I submit trappistplanets' fix suggestion to 'DEV ideas' or to 'BUGS' or to GitHub?

As I said in your other thread, I've already opened an issue.