It's primarily artistic. I give you an over-the-pole shot of Saturn, looking straight down on the plane of the moons and the rings. You can print it and measure the visual angle Saturn or the rings would subtend from any of the moons. I've done it for Enceladus to show what I mean. Saturn would just sprawl across the sky. The rings wouldn't be terribly spectacular. They're even wider but all but the most distant satellites orbit within a degree or so of the ring-plane. You'd just see a thin line. But they'd cast a large shadow across the planet most of the Saturnian year.
Most of the moons in the System would look pretty insignificant from the surface of their primaries. Charon is fairly large and close to Pluto, but the lighting is bad.
The triple-star pix is an artist's conception. No way NASA could take an actual photo of the scene.
Isaac Bailey
For an observer on Io, the closest large moon to the planet, Jupiter's apparent diameter would be about 20° (38 times the visible diameter of the Moon, covering 1% of Io's sky). An observer on Metis, the innermost moon, would see Jupiter's apparent diameter increased to 68° (130 times the visible diameter of the Moon, covering 18% of Metis's sky). A "full Jupiter" over Metis shines with about 4% of the Sun's brightness (light on Earth from a full moon is 400 thousand times dimmer than sunlight).
Because the inner moons of Jupiter are in synchronous rotation around Jupiter, the planet always appears in nearly the same spot in their skies (Jupiter would wiggle a bit because of the non-zero eccentricities). Observers on the sides of the Galilean satellites facing away from the planet would never see Jupiter, for instance.
In the skies of Saturn's inner moons, Saturn is an enormous object. For instance, Saturn seen from Pan has an apparent diameter of ~50°, 104 times larger than our Moon and occupying 11% of Pan's sky. Because Pan orbits along the Encke division within Saturn's rings, they are visible from anywhere on Pan, even on its side facing away from Saturn.
>100 times bigger than the moon >primarily artistic
Pic from an orbiting probe. Phobos is 10 km across and about 6000 km above the surface of Mars. That makes it a 10th of a degree across vs. half a degree for our own moon. Phobos is one of the least reflective bodies in the Solar System, with an albedo of just 0.071. If it didn't move so quickly, you'd have a problem finding it in the Martian sky.
Nathan Walker
Oh thanks I didn't know. But it's still really smaller than how we represent it in sf right ? What would it takes for a planet or a moon to look that big in the sky ? Would a gas giant look like that from one of it's moon ? Is that common to have many that many moons and we are the exception with our only moon ?
Thank you that was really interesting. The ring-thing sounds pretty cool. I knew it was an artist's conception, like every photo of exoplanet we have but I wondered if it was realistic
Wow that's great. I knew that would be something interesting to ask. Thank you
Gabriel Gonzalez
19 billion dollars a year for shitty cgi, "composite images" and wide angle footage is plenty user...they definitely don't need more money.
Andrew Richardson
Realism killed video games
Evan Jones
I said Saturn would be spectacular. But the rings are incredibly thin. This is as close as I could get to a shot from Pan. It's currently on the nightside of Saturn, so there wouldn't be much to see. If you zoom in, you can see the ring-planel lower left to upper right. It just looks like a scratch. I've turned off the orbital-tracks of the moons so they wouldn't obscure the view.
