The oldest oral traditions amongst the indigenous peoples of the earth involve the question of a Purple Dawn, that is, an age spent in some kind of a deep, dark, purple twilight with nothing at all resembling what we call daylight. That turns out to be more than just some sort of a myth.
The story seems to begin with the axis tilts of the bodies in our system, which are known now.
The numbers are not what somebody committed to standard views of cosmology would anticipate. Given the standard versions of the formation of our system, one would expect all of the rotational axes of the planets to be roughly perpendicular to the plane of the system; that is not what we see. Our sun, Mercury, and Jupiter do look a bit like that with axis tilts under 10°; it would be reasonable to assume that those three bodies represent an original system.
There are two bodies in our system (Venus and Uranus) with oddball axis tilts; each of those two has its own special little story.
But the other four bodies with the roughly 26° axis tilts (Neptune, Saturn, Mars, and earth) represent a gigantic anomaly. You would think it would be reasonable to assume that those bodies had been captured as a group, but you would then have to ask yourself what is it about being captured as a group which would produce those nearly equal axis tilts?
The answer to that one requires an adjustment in thinking. Gravity is by 40 orders of magnitude the weakest force in nature, asking gravity to hold a spiral galaxy together or to cause the formation of a solar system from dust or plasma is like asking the littlest kid in the school to do the power lifting event, i.e. the entire narrative we've heard about how solar systems are formed turns out to be garbage.
In real life, solar systems do not form up as orbital systems like our present solar system. They are created by what is called Herbig/Haro objects or strings which are themselves created by the Birkeland currents which arc through the plasma of space. A Birkeland current is a twisted pair of currents resembling an RNA/DNA string with short-circuiting at the electromagnetic pinch points where the two currents cross each other, called a Z-pinch points. Those electromagnetic pinch points do have the power to agglomerate plasma into solid objects, stars, proto-stars, and other large bodies.
What appears to be the case is that Neptune, Saturn, Mars, and Earth, still in the form of a partial Herbig/Haro string, flew into the plane of the sun/Jupiter/Mercury system from the South at something like a 26° angle and, as the individual bodies peeled out and began to orbit as they do now, ordinary gyroscopic force caused them to retain the 26° angle of approach in the form of axis tilts.
Prior to that happening, our system was in two parts:
1. A very bright northern part consisting of our sun, Jupiter, and Mercury and, without the other bodies in the system at that point, it is reasonable to assume that Jupiter along with its moons would have been substantially closer in to the sun as is more the normal case within the Milky Way galaxy, probably within the habitable zone. And
2. A very dark southern system consisting of Neptune, Saturn, Mars, Earth, and possibly other bodies at the time. In particular, Mars and Earth would have been inside the plasma heliosphere of Saturn which would have been a dwarf star under such circumstances. Troy McLachlan describes this ancient southern system in his book "Saturn Death Cult" and some of that material is available at www.saturndeathcult.com.
As the image indicates, you would have radiant energy coming to the planets from all angles, that is, it would be bouncing off the interior of this plasma heliosphere and coming back towards the rocky planets; you wouldn't freeze to death, but the whole middle part of the light spectrum simply would not be there.
That is the meaning of the idea of a purple Dawn and it is the reason for the huge eyes which we see in left over old creatures of the earth (lemurs, tarsiers, Bush babies, owls, owl monkeys...) And which we also observe in the remains of dinosaurs and hominids. Those creatures never saw anything which we would call daylight at all.
Vendramini Neanderthal reconstruction
Humans and Dolphins, of course, do not have eyes like that. In fact, humans and Dolphins have the smallest relative eye sizes of advanced mammals. Given a prehistoric system divided into bright and dark parts, humans would have to have originated in the bright part. And, in a bright system consisting of our sun, Jupiter and its moons, and Mercury, the one thing which is easy to picture having been an original home world for humans, would be Jupiter's largest moon, Ganymede, which would have been a freshwater ocean world at the time.
Videos related to the Ganymede Hypothesis:
In book form:
Of course, this stuff completely wrecks any sort of a notion of humans having evolved from hominids. Humans and hominids don't even come from the same world and are related only via similar design.