ISS transits of the Moon

[Dirk Devlies]

Hello all

On March, 22nd 2026 I was watching my first ever Moon transit by the ISS. It made me discover a bug in Stellarium. It appears that the Moon is occulting the ISS. So, the ISS temporarily disappears behind the Moon, instead of passing in front of the Moon. It might be difficult to display a satellite-icon for that short period of time, but the ISS should not dim.

Kind greetings

Dirk

Bruges, Belgium

[Georg Zotti]

I think several years ago we invested some effort to make the bright ISS vanish and turn into a dark figure when it transits the bright Moon. Zoom in to see the effect.

[Paul Gilmartin]

On 3/22/26 14:06, Georg Zotti wrote:

I think several years ago we invested some effort to make the bright ISS vanish and turn into a dark figure when it transits the bright Moon. Zoom in to see the effect.

    ...

For example, objectively, on an airless planet, or even non-airless,
stars do not dim when the sun is in view.
But subjectively pupils contract and retinas bleach; stars vanish.
But computer displays have a limited range of luminance.
Stellarium seems to try to replicate this appearance by
dimming the stars in daytime.

But how should this apply when an extended object such as
ISS transits another ( of comparable luminance?) such as
the moon?   Should it vanish because of insufficient contrast?
Similarly, what about mutual events of  Jovian] satellites
(I haven't tried -- are they even shown as disks?)

-- 
Thanks.
gil