George Jones went to Ecuador to study the zodiacal light. So we did too.
My desire was to proceed to Quito, where, in its proximity to the equator and in the transparent atmosphere of its great altitude, I hoped to have peculiar advantages for my work. At the equator, an observer must have the ecliptic vertical to him, at some hour or other, every night throughout the year… My hope was to be able to ascertain exactly the position of this nebulous ring in regard to the ecliptic….
Observations on the Zodiacal Light at Quito, Ecuador, with deductions. The American Journal of Science, 1857, p. 374
Sounds like good advice. In other words, you can see the zodiacal light anywhere. But to be able to distinguish whether the zodiacal light lies along the ecliptic or not, your best shot-in-the-dark at this observation is to go to the Equator.
Imagine that you are watching a highway from the sidelines and you think one of the drivers is swerving back and forth across the highway, right lanes to left lanes and back. You couldn’t really be sure if you were on on the sidelines a block away, but if you could get onto the median strip, you would know for sure. Exactly the same way, the equator is a good latitude for watching the ecliptic: at some hour or other, every night throughout the year, Quito is like being on the median strip of the ecliptic. If the zodiacal light is a great circle tilted a few degrees from the ecliptic, rather than lying along it, in Quito you could tell.
But there is a problem….
Quito is much troubled with clouds and rains. Nine months in the year are rainy; and only June, July and August are usually favored with clear skies; sometimes the clouds and rains continue through all the year….. I was not able to reach Quito till the close of August; from which time on, during all my stay of eight months on the Cordilleras, I had to contend unceasingly with the clouds.
Ibid, p. 375
It has just been too cloudy so far.
Our first month in Ecuador, July 2018, had some clear nights, but that month’s work was no good because I had not found a good place for photography of the night sky. In our second month, August 2018, we moved to a place with a great balcony (in Cuenca). By then it was generally too cloudy at night. I did all-night time lapses so I am really sure. Beautiful afternoon skies would turn cloudy at sunset and stay that way all night.
But when the sky is clear it is a superbly glorious sight, such as I have never beheld in any other part of the world. The heavens are then fairly crowded with the smaller stars: and the Milky Way has a brightness and an apparent proximity wonderful to behold. … Soon after reaching these altitudes, on going out, about midnight, to see whether I could find the Zodiacal Light over both horizons…. I saw this light not only over the horizons but alsoquite across the sky.
Latest word is that the Moon is not dead. It is geologically active and shrinking a bit over time as a result. Well if that is so, then where has the missing material gone? The dynamical multi-body problem is too hard for a wave of the hand, but to the extent we can think of the Moon as if only the Earth mattered to it, this is a binary system, in which case, the littler one usually unspools onto the bigger one.
If we think of the Earth-Moon as a binary system, that suggests the Moon stuff is coming here. If so, there must be a lot of it already arrived, so we are familiar with it though wrongly thinking of it as terrestrial – but what about the deposit in space that has not landed yet? Where is that? (The stuff that is on the way?) This kind of mass exchange is usually mediated by an accretion disk, which we can also call a dust ring around Earth.
dust ring of haumea or something
Hard to say much about the size range to expect – but calculations are that YORP would lead a small rock to spin up until rotational bursting in about ten thousands years (ref.) and so more dust, less big stuff, is how it would evolve, rather quickly at that.
And as for the form of the disk, the cloud of stuff would organize itself into a ring with resonant gaps and so on, better and better as long as it was wandering around up there not much disturbed by bigger effects than our gravity. Though this would depend on how much there was and its size distribution, so, don’t really know.
Over time it could well organize a secondary structure, a ring of dust in the Earth’s equatorial plane, because dust does tend to do that, no matter where it originally came from. It makes a dust ring around a planet’s equator, as Maxwell explained.
Don’t know how often the Moon blows, don’t know the size of what it puts out. Lot of uncertainties here. Mostly uncertainties actually. Is it worth thinking about – speedily, even, or may the centuries well pass by while we take up each aspect in turn?
You can make a lot of disasters out of a dusty Earth ring that is always falling to Earth – clumps and streamers of cold charged dust possessing angular momentum of the moon could land in the form of hurricanes, wildfires, sandstorms and tornadoes, causing in the process droughts, lightning, storms, desertification, ENSO, and darkness at noon – you can make all those things out of cold charged dust falling into the atmosphere, dust with the highest charge-to-mass ratio being deflected by the Earth’s magnetic fields, other material hanging on in orbit until local rest in atmosphere, land or water; larger grains prone to plummet and burn, silt to drift inward and accumulate somewhere; some sizes organizing raindrops and other sizes inhibiting their formation; dust grains twisting air and water currents or shoving the mountains ever so slightly, with an effect depending on latitude; and material not heated in its fall ultimately depositing cold to air or land or water; the whole structure tending to reflect sunlight away from Earth.
In Vedic astrology Rahu and Ketu are known as two invisible planets and they are strong enemies of the Sun and the Moon. Rahu and Ketu are actually the astronomical points in the sky respectively called the north and south lunar nodes. The places of intersection where the Moon`s path meet the Sun`s path is known as North Lunar Node and South Lunar Node respectively.
The first people to suggest anything like an Earth ring are all the cultural ancestors who have passed on the notion of a dangerous serpent in the sky that swallows the Sun. The Hindu version of the story is that of Rahu and Ketu, as above. To see the perfection of that myth as a description of the appearance and effects of an Earth ring, consider this: If the Earth has a ring system like those of other planets, there are only two orientations it can occupy, based on the rings found so far in the solar system: the equatorial plane, which at any given location would always be in the same place in the sky, and the plane of our Moon – a ring analogous the Phoebe ring of Saturn. The sky position of such a ring would vary for an observer. It would cross the path of the Sun in two places, the nodes of the lunar orbit. Hindu astrology has been keeping track of those nodes for thousands of years, calling them Rahu and Ketu, warning that when the Sun crosses them, there will be a maleficent effect, and associating this passage with the notion of a serpent that darkens the Sun. If our Ice Ages were caused by a ring system once denser than it is now, then such a ring scattering sunlight forward when the Sun passed through the nodes of the lunar orbit could well be expected to blaze out once a year as a bright streamer whose brightest extremity “swallowed” the sun, and a second time as its brightest extremity “disgorged”| the Sun out its other end.
HER I NEED A PICTURE
Since the mythological era, two people have suggested that the Earth has a ring system – First, was George Jones, the zodiacal light observer, who made careful observations in tropical latitudes over several years. Finally, he said that his observations did not accord with the theory of the zodiacal light as illumination of a dust ring around the Sun. Instead, the dust ring should be around the Earth, somewhere near the ecliptic. He got nowhere with this idea because there was no known reason for dust to accumulate in the ecliptic plane.
Third was John O’Keefe, who was interested in the origin of a puzzling kind of rock called tektite, distinct for the fact that it has no motherlode of similar material. Also for the fact that while its form is like lava, its composition is just exactly like terrestrial sand.
O’Keefe said tektites were splashed off the moon by impacts – this explained their lava-like structure because the material was the product of ancient lunar volcanism. But the Apollo missions found very little tektite material on the Moon’s surface and that was the end of O’Keefe’s impact theory. There should have been tektites all over the lunar surface and there were not.
Most people then concluded the rocks must be terrestrial, even though they could not explain the lava-like structure – so very dry, so very fine, not just any lava. But O’Keefe stuck to it that as such fine glass could not be made anywhere on earth they must be lunar, and if they did not come from the Moon by impact, then it was by recent lunar volcanism. A dangerous reality that we should attend to!
But there was no other significant evidence for geological activity on the Moon, and so O’Keefe’s idea was not accepted.
To the end of his life, O’Keefe worked out answers to the challenges to the lunar origin of tektites. One was: If this material came from the Moon, then considering what a small angle the Earth subtends, there must have been much more material, and where is that now? It should have fallen to Earth eventually, the same kind of material, and where is it? In answer to this, O’Keefe worked out with a graduate student that rocks in space would spin and burst, an effect sometimes called the YORP effect – thus, the material would fall to earth as smaller particles, not identifiable as tektites but having the same composition. And also – in 1980, O’Keefe began to write about the possibility that Earth might have a ring system of its own, whose coming and going would be modulated by solar activity, and which could drive the coming and going of the Ice Ages.
If we want to look for an Earth ring today, these three predecessors suggest where we may to look to see what they saw: (1) As for the solar radiation – is it affected systematically every year as the Sun passes through the two possible ring planes? (2) As for the zodiacal light – does it show the same effects that George Jones describes, which are incompatible with Cassini’s theory, at the times expected from a ring hypothesis? (3) As for weather and climate – can we forecast global teleconnections from a ring hypothesis?
So this blog is to describe my efforts along those three lines: a solar radiation database, moving to the tropics to try to photograph the zodiacal light, and trying to forecast the global teleconnections.
A closing remark: People ask from time to time why the spacecraft have not seen such a ring if it exists. Just a few remarks: (i) The spacecraft do not look backward toward Earth in a wide view with the Sun behind it, the view which would make a ring blaze out in forward-scattering light, because by the same token, the Sun would be behind the Earth, bigger than the Earth, and would dazzle and blow out the cameras. Spacecraft tend to photograph the Earth side-on, which is not a favorable way to illuminate a faint ring. (ii) The ring would not be sharp and thin like Saturn’s. Thus tests that search for a ring that offers a high density compared to background will not find it. As O’Keefe pointed out in 1991, Maxwell’s original paper shows that it is the oblateness of Saturn specifically, its non-roundness, that sets a favored plane for particle orbits far out in space, flattening orbits and sharpening a ring. But Earth is rounder than Saturn, and it follows that the favored equatorial plane is less favored than Saturn’s, and the ring it would develop would be lower-contrast. Actually all the gas giants are oblate, and those are the ones with sharp rings. Little dwarf planets are also asymmetrical and some of those also have perceptible rings (Haumea and *). The rocky planets are the rounder ones: Mercury, Venus, Earth and Mars. And these are the ones that do not have perceptible rings. The dwarf planets are rocky too, but not round; some of them have rings. (iii) Although there are observational programs that search for rocks in space, the surveillance is weak for orbits in the favored planes, and it is also weak for small particles. They are looking for football-sized objects in polar orbits.
And in sum, …more could be said, but we will leave it that we must reflect on what the observational test would be exactly, before we are sure it has been made. I have tried to undertake or search for all the observational tests that could disprove this idea, so as to save myself time wasted on an error, and it appears to me there is no test the ring hypothesis has failed. Not to say it is proved – but it has not failed.