Recently, Judith Curry, a well-respected climatologist, stepped down from her position at Georgia Tech because of the politicization of climate science. It is a problem! And after many years of politicization, we are now in the situation where so many positions of influence are held as political plums, that it is easy (and true) to say that there is a consensus on anthropogenic global warming. Fire everyone who does not agree, and you have consensus.
What if Earth had a ring?
Today, I would like to mention a very interesting possible driver of climate: suppose Earth had a ring.
If we had a ring, it would cause shading on the Earth. Furthermore, as Earth traveled around the sun, the shade of the ring would fall on the northern hemisphere for one half-year and on the southern hemisphere for the other half-year. Indeed, it would fall on the northern half during our winter, and on the southern half during “their” winter. The effect would be to intensify winter. So who would notice that? Bears?
Where would the ring come from
But a ring is made of stuff – dust essentially – and that stuff would eventually fall down. Even a very fine dust would eventually fall to Earth, and after that, there would be no ring. So a ring has to be fed more dust, and there is only one way to do that efficiently: get the Moon to contribute dust on a moderately regular basis. This requires that the Moon be geologically active – it must have active volcanoes.
There is a big argument about that, but if it has volcanoes, it can supply a ring. In fact, if it has volcanoes, we must certainly have a ring, because some of what explodes upward on the Moon will not fall down. It will orbit the Moon, then be captured by the Earth and orbit Earth in an Earth-Moon orbit, then collapse into a Moon-tilted Earth orbit, then fall into an equatorial orbit, and finally fall down.
If lunar volcanoes, then Earth-ring; if Earth-ring, then lunar volcanoes.
Surely we would see it!
How could we not see an Earth ring? We see the rings of Saturn from millions and millions of miles away. Over a billion, actually.
Two reasons not to see an Earth ring:
First: Because Earth is rounder than Saturn (Saturn is more oblate), our ring would be more diffuse, more fluffy. It would be harder to see. Ask your local physicist about that.
Second: The rings would be relatively close to the Earth, and would be visible, if at all, only near the horizon. When we do astronomy, we look up very high. We don’t look near the horizon because there is a lot of interference there – city lights for one, and haze of various kinds for another. If we want to see something close to the eastern or western horizon, we choose a different time of night, when our target star is up high. If we want to see something close to the northern or southern horizon, we move north or south.
How might on see it?
There is, of course a third reason not to see it: we are not looking. If we were looking, and if we knew exactly what we were looking for, we might see it.
Somebody might go to Jamaica, for example, where the southern horizon does not have any cities. She might get a time-lapse camera and just photograph the sky all night. If there were a ring, she would see the stars against that light familiar haze that makes astronomers not do near-horizon investigations, but she would tell herself it was the ring dust, illumined by the Sun long after dark, because it is so high – one or a few ten thousands of miles or so.
She would expect that in the middle of the night, the shadow of the earth would fall on the ring and this “light haze” would disappear for a few hours. Since there would be no cities turning off their lights to deepen the darkness, she would have evidence of the ring. This has been done, and the darkness did seem to appear. The camera was cheap, and the darkness not spectacular, but it seemed to be there.
And you don’t have to go to Jamaica. Any place in the middle latitudes that has no cities for a long way south will work… In high latitudes, the rings would be too low on the horizon.
I mean, does this have consequences?
Well, don’t you see, the rings would – or might — be a significant climate driver. We do know that the ice ages were primarily a result of colder winters. Colder winters do cause late summers, which may then be cooler, but the problem is a winter problem. That is how rings would affect climate: colder winters first of all. However, because rings could be a climate driver, their study is not a way to get tenure or good appointments; the only climate driver permitted to be discussed is human activity.
Nevertheless, whatever is, is, and whatever isn’t, isn’t. If the Moon is active, there must be rings. Go find them.
Where do rings go
So if the rings are composed of Moon dust, where do they go? After all, if the Ice Age was caused by the rings, where did they go? The dust fell down, okay, but what makes the dust fall one year (or one decade or century or millennium) and not another?
Well, if the dust is very small (and the YORP effect guarantees that it will end up small if it doesn’t start small) if it is very small, then solar storms, which release floods of high-energy charged particles, can cause a sudden downfall of dust from one sector of the ring. The immediate effect might be a local storm, possibly quite a large one. Unexpected storms are not so unusual. During a phase of very active sun, lots of sunspots that is, the ring would erode very considerably. But during quiet sun, the ring could get thicker.
We do know that the Maunder minimum was a time of very few sunspots, seventy years with no spots visible, and the Jesuits were watching closely. The Maunder Minimum is the middle of the Little Ice Age. So there is a correlation; there might be causation.
There might be.
Quiet sun might cause thickening rings, colder winters. And we have a very quiet sun these days, these years. You can’t wake up the sun by parking your car.
Has anyone really seen a ring
The ancient astronomy sites such as Newgrange in Ireland have lots of astronomical markers, and then lots of mysterious loops that have no astronomical significance at all. Were the rings visible in those days? We really do not know, but Lucy Hancock offers this visualization of the rings.
One more question
If there is a ring, or a set of rings, even a mushy one, and if the ring is thickening, could it affect the visuals of an eclipse? We in the United States have a very spectacular eclipse coming up in August. We are hoping for millions of people to see the wonderful corona of the sun; it is said to be the most beautiful, most awesome of sights.
If — If — If there were a ring, and if the path of the ring crossed the path of the view of the eclipse, (and if there were no clouds) then if the corona diminished at a certain point for no good reason… That would be very sad for the viewers, but very interesting for the ring seekers.
We could calculate where the ring, if there is one, might intersect the path of the view of the eclipse, but nobody has done that yet. It is not a priority. Return to top…