Ok, first lets look at the real world, the Sun is about 864,949 miles in diameter, at an average distance of 92,956,229 miles, and thus has a visual angle of 0.533°. The Moon is about 1,079 miles in diameter and is at an average distance of 238,855 miles, and thus has a visual angle of 0.518° - which is about the same as the sun, thus we get eclipses.
In Greyspace, the sun is a world called Liga, which orbits Oerth at a distance of 100 million miles, and has a diameter of 75,000 miles. Thus it has a visual angle of only 2½ arc-minutes (0.043°), or about 1/12th of that of the sun seen from the Earth!
Oerth's nearest moon, Kule, is a class B planet, and so mas a maximum diameter of 100 miles, and orbits at a distance of 10 million miles, it thus has a visual angle of 2 arc-seconds (0.0006°), or less than 1/900th of that of the sun!
But the Greyspace supplement describes Kule as being about the same apparent size as Liga, as seen from Oerth, where it actually has about 1/80th of the visual angle.
To make Kule and Liga have similiar apparent sizes, we need to either enlarge Kule to 1/10th the diameter of Liga, making it about 7,500 miles diameter (Class E, and bigger than Oerth), or shrink Liga to 10 times the size of Kule; not bigger than 1,000 miles diameter (Class C).
Charles
I'm not really sure how many people really "like" the Greyspace supplement. It was not well-recieved by the Greyhawk crowd, and even amonst the SJ crowd, its not overly popular. :p
I think the intent is that Oerth's sun & moons should be comperable to that of Earth's, visually. So the sun should probably be slightly larger than ours, Kule should be roughly as big as our moon & about the same distance, while the other moon should probably be a bit larger & a bit farther out than Kule.
Pretty much my solution as well, Makes Liga size class H (1 class increase), and Kule borderline Class C or D and much nearer to Oerth. Then Raenei would by 3-4 times the diameter of Kule (Class D) and 3-4 times further away. So we can get away with bumping the size of two planets, and altering two orbits - leaves quite a big gap though. Alternatively we shrink the whole sphere by a factor of about 10 ;)
I'm not really sure how many people really "like" the Greyspace supplement. It was not well-recieved by the Greyhawk crowd, and even amonst the SJ crowd, its not overly popular. :p
From reading these forums and the archives of the mailing list, I get the impression that none of the three core sphere supplements are much-liked, for a variety of reasons. The problem with the planet sizes and distances, however, originates in the sphere write-ups in the original Spelljammer boxed set. I'm wondering if I'll find similar problems with the other spheres...
Charles
.Charles
Pretty much my solution as well, Makes Liga size class H (1 class increase), and Kule borderline Class C or D and much nearer to Oerth. Then Raenei would by 3-4 times the diameter of Kule (Class D) and 3-4 times further away. So we can get away with bumping the size of two planets, and altering two orbits - leaves quite a big gap though. Alternatively we shrink the whole sphere by a factor of about 10 ;)
Not unreasonable, any of it. Greyspace is pretty huge, and could probably be trimmed down to make SJ travel easier.
From reading these forums and the archives of the mailing list, I get the impression that none of the three core sphere supplements are much-liked, for a variety of reasons. The problem with the planet sizes and distances, however, originates in the sphere write-ups in the original Spelljammer boxed set. I'm wondering if I'll find similar problems with the other spheres...
They're not overly popular mostly because
1) the planets are uneven in treatement
2) little sense of unity
3) very little to "do" in any given sphere
4) you can barely tell its the solar system of the primary planet...aka there's little "FR" in Realmspace.
And yes, you'll find all sorts of problems with the other sphere guides. Such as Krynnspace missing an entire planet, yet having two "extra" planets tacked on once they realized there was almost nothing for spelljammers to do in the sphere.
With further thought, I've found This Site which offers another, probably better solution. Though I've noticed that none of the SJ sphere books seems to take any notice of Kepler's laws of planetary motion
Heh, can't claim to particularly use Kepler's laws (sorta difficult, regardless, since SJ planets can have wierd planetary masses, especially with air worlds) myself.
What I've done is shrink the orbit of Liga to about 8 million miles (which gives it an apparent size roughly equal to that of Sol seen from Earth) and re-sized the moons and their orbits to fit. I'm shrinking the orbits of the other bodies by an amount that reduces the further they are from Oerth, so the inner system is a lot less spaced out, while the overall size of the sphere is unchanged.
Charles