Under very good observing conditions, there are some interesting lights in the night sky.
The first is the zodiacal light, so named because it is a faint lane of light across the sky in the area of the zodiac, the ring of 12 constellations through which the Sun seems to move, — that is, if you think of the Sun circling Earth, as people imagined through all the years when the constellations were getting their names.
But not only the Sun; let me say more.
Where are the planets?
The planets, including Earth, orbit the Sun as if they were sitting on a disk that spins round with the Sun at the center. That is, they don’t orbit every which way in three dimensions, but sedately, one orbit beyond the next so that the solar system is flat as a pancake – even flatter. It’s not really two-dimensional, of course, but it’s pretty flat, and if Earth spun on an axis that was vertical with respect to the solar system, the planets would always pass directly overhead.
Because the Earth is tilted on its axis, however, the passing of the planets changes over the space of the year. Thus, if we look out into the system from Earth, on the equinox, (either March 21 or September 21, any planet crossing the sky will be visible about as far down from the zenith as the latitude of the observer.
Thus: if you are on the equator, the planets will pass right over your head; if you are at latitude 23°, they will be high in the sky, about 67° above the horizon. (90 – 23 = 67) In Venice (Italy), or Minneapolis (Minnesota), at latitude 45°, planets will be halfway between the zenith and the horizon. From the poles, the planets will be right at the horizon and not actually visible.
At all other times of the year, there has to be a correction for the tilt of the Earth. In our northern winter, Earth’s axis northern is much closer to the disk of the solar system, and the planets are quite high in the sky. At the same time, for southerners, planets are low in the sky. In our summer, it is the opposite: planets are to be found closer to the horizon in Europe Asia, and America, but higher in the sky for Australia and for most of South America and Africa.
You can get a planisphere, or star wheel and check this for yourself. It is fairly easy to make one, and also easy to buy one. The complication of making one is that they have a slightly different construction for different latitudes.
With or without a star wheel, we learn that the zodiac is the band of twelve constellations above our tropics, and the zodiacal light is a faint band of illumination in this area. It is believed (by almost everybody) that this dust might have been dropped by comets on their way close in to the sun; or it may be infalling dust from broken-up asteroids, or perhaps it is leftover from the beginning of the solar system. These would all be reasonable dust sources. Any such combination of sources could make a kind of pancake of dust orbiting the Sun, and that pancake could be visible from earth as a pale streak across the night sky. Wikipedia has an image by Y Beletsky, working from the Southern Astronomical Observatory in Paranal, in northern Chili.
I presume that the bright star at the top of the image is Venus. And in case you are wondering whether it is dawn, it is not; I believe it is near sunset. The zodiacal light does give a false impression of dawn — remember the zodiac is the set of constellations where the Sun travels.
And here is another image, close to sunrise, with both Venus and Jupiter caught in its glow.
But could the zodiacal light really be a dust ring around Earth instead of a dust ring around the Sun? It would look like a streak either way; it would be in the zodiac either way. If it were around the Earth, we might conclude that the Phoebe ring is visible and it has been seen: it has simply been misidentified.
This is not an easy question, and I cannot answer it, but I can offer a reason to examine it further.