Portents in the heavens

[Desdichado]

Here's an idea I've had recently. Let's say that our fantasy world is a planet of a star in LMC, or SagDEG, or some other small galaxy that's a near satellite of a large spiral galaxy like the Milky Way. If so, the big spiral would literally dominate the night sky, and may even be easily visible during the day. The nucleus of the galaxy would be at least as bright and as big as the Moon in our sky, and the flocculent spiral arms would spread over nearly half the sky at night. You could probably easly make out the halo of fuzzy globular clusters easily with the naked eye (and tell what they are), and you might also be able to see other smaller satellite galaxies, and depending on your location within the small satellite galaxy, you might also have a relative paucity of stars.

What kinds of mythology would cultures on this world use to explain such an astonishing sight in their everyday night sky? My idea is that the human inhabitants of such a world are migratory; they traveled through some sort of gate to arrive here from a planet within the larger galaxy, and brought with them a small selection of their own animals and plants, which have since spread amongst completely alien flora and fauna. But that's so long ago that even legends barely hint at it, and certainly nobody has preserved that as a historical fact. So, whatever role the big spiral may once have had, is lost in the mists of time, and it's only the source of various myths as a magnificent portent in the heavens.

Any ideas?

 

[radferth]

This sounds very cool, but I'm not sure the view would be that good in real life. We are inside the Milky Way, and we can barely make out most of the stars in it because they are too far. If you were in one of the Magellanic Clouds, you would be even further away from most of the stars in the Milky Way. Maybe you could make out the spiral because there were so many stars, but it would be very fuzzy. Of course, if this is more of a fantasy thing, then their is no reason why it couldn't be just as you described. I can imagine a society with a low tech level, but with a knowledge of astronomy about what we had before radio telescopes.

 

[Desdichado]

You should be able to make out the spiral very well. We can make out the LMC and SMC quite well as large white smudges in the sky that look like unattached portions of the Milky Way, so I don't know why it should be any different looking the other way. Sure, you wouldn't make out very many individual stars (unless they went supernova or something) but I don't see why that's a relevant point.

Keep in mind, most of the reason we can't make out the Milky Way very well is because of all the light pollution. If you're out in the middle of nowhere, or if you lived before the mass industrialization and urbanization of the world, you can see the Milky Way very clearly. And the reason we can't see the much brighter parts of it, i.e., the nucleus, is because it's obscured by interstellar gas and dust, not because it's too far away.

 

[palleomortis]

Sounds like a fun job. I will talk with some friends that would be a little better, put together a suggestion, and get back to you. Until then, my suggestion is steal stuff from our own myths. How did the sun come, the moon, the starts. Native Americans seem to have a vast amount of stories to explain such things in the univers.

 

[BlackMoria]

In the model you propose, the large spiral will be a dim glow. A parallel would be looking at M13 the Great Globular Cluster. I live in a area with dark skies and on a good clear night outside of town, I can find M13 with the naked eye. It appears as a very faint fuzzy blot. Only with binos or a telescope can I resolve stars at the edge of the cluster.

If you want a theorical magnificent view, put the world around a star in the centre of a globular cluster like M13. Astronomers estimate that stars are about a 1/4 of a light year apart.

So the sky would be filled with stars with a apparent magnitude greater than Sirius, which if my memory serves, is about magnitude -1.0. I would say that magnitude would be about -5 on average with stars that close. And the star field would be very dense.

 

[Desdichado]

In the model you propose, the large spiral will be a dim glow. A parallel would be looking at M13 the Great Globular Cluster. I live in a area with dark skies and on a good clear night outside of town, I can find M13 with the naked eye. It appears as a very faint fuzzy blot. Only with binos or a telescope can I resolve stars at the edge of the cluster.

The absolute magnitude of a galaxy is way beyond that of a globular cluster. M31 (Andromeda) is at -22, I believe, for instance. And several galaxies are visible to the naked eye as it is (including Andromeda). Shorten the distance tremendously, as I suggest, and it would indeed dominate the sky as I've described. I don't know why you suppose that the spiral would be only a dim glow. The spiral itself would be as bright as the Milky Way on a clear night far away from any lights, which is pretty spectactular, and the central bulge/nucleus would be dramatically brighter still.

If you want a theorical magnificent view, put the world around a star in the centre of a globular cluster like M13. Astronomers estimate that stars are about a 1/4 of a light year apart.

So the sky would be filled with stars with a apparent magnitude greater than Sirius, which if my memory serves, is about magnitude -1.0. I would say that magnitude would be about -5 on average with stars that close. And the star field would be very dense.

Yes, but conditions in globular clusters are such that it is extremely unlikely that any planets exist. Because of the various gravitational interactions, a stable orbit around a star would be extremely difficult. Not only that, the barrage of cosmic rays would probably fry any attempt at the development of life on any planet that did manage to maintain its position. And then, the more dramatic interactions; stars going nova, stars going supernova, stars colliding and forming blue stragglers, etc. makes any already difficult planet extremely unlikely to be able to harbor any life like we know it. And finally, globular clusters are generally all part of extremely old, red and orange giant type stars, which means they've swollen, shed off their outer layers, and undergone all the various stages of stellar evolution already that would blast any planets to cinders to say nothing of the life on them.

No, I've thought about the concept of a planet in a globular cluster, but really the only thing about it would be that the night sky isn't very dark, because a lot of very bright stars would cover the sky all the time. That's not nearly the effect I want, and it's also scientifically implausable.

 

[helium3]

You should be able to make out the spiral very well. We can make out the LMC and SMC quite well as large white smudges in the sky that look like unattached portions of the Milky Way, so I don't know why it should be any different looking the other way. Sure, you wouldn't make out very many individual stars (unless they went supernova or something) but I don't see why that's a relevant point.

Keep in mind, most of the reason we can't make out the Milky Way very well is because of all the light pollution. If you're out in the middle of nowhere, or if you lived before the mass industrialization and urbanization of the world, you can see the Milky Way very clearly. And the reason we can't see the much brighter parts of it, i.e., the nucleus, is because it's obscured by interstellar gas and dust, not because it's too far away.

Yeah. If you get outside urban areas, the milky way is actually pretty obvious. I'm not sure you'd be able to see it in the day, though.

 

[Varianor Abroad]

Have you ever read Nightfall, by Isaac Asimov? Good source material. Great SF.

I would imagine nobody on the surface would have darkvision.

But as to myths? Good question. Perhaps they don't have much 'darkness', so the mythology pertains to different colors of light which take on the different light/dark and good/evil roles. Perhaps there is a strong polytheistic element pertaining to the cluster/galaxy.

Do they see it as a serpent coiled? Or as bread rolled up ready to bake? Could it represent a mysterious gate in the heavens? (The original inhabitants always intended to repair their ship and get back to the spiral.)

Or is getting closer? Are there fears of the world getting hotter and drier and nastier due to the Great Eye?

 

[D-rock]

Actually, I think the Magellanic Clouds(if you count them as seperate form the Milky Way) and the Andromeda Galaxy are the only galaxys seen by the naked eye. (I could be wrong so I'm not betting the farm on it) I would also agree that if you were just outside the galaxy looking in you probably wouldn't see the spirals like you think you would, and the galaxy wouldn't be any brighter than the milky way is now from our point of view, at least you are not going to see it during the day.

I wouldn't let that stop you from putting whatever you thought was cool in your world though.

 

[palleomortis]

It usually works to make it happen in the war of the gods or somthing. I haven't had a chance to talk to my friend, but I will as soon as I can remember.