Thursday, March 28, 2013

Climate change - Suppose an Earth ring...

It was my father's idea.  He was a lunar scientist at NASA.  In 1980, he published a note in Nature, saying out that if the Earth once had a ring like Saturn's, the shade cast on Earth by the ring could have caused an Ice Age.  This would explain a strange thing about the Ice Ages, namely that the climate mainly cooled in winter only.

Here is a video that shows why a ring in the equatorial plane, like Saturn's famous bright ring, shades only winter.



The idea he published was strictly limited, but when he and Mom talked about it at the dinner table, they used to speculate about what that ring might have looked like in the sky.  After all, the last Ice Age faded away about 11,000 years ago, so there would have been people to see a bright Ring if it were in the sky then.  Eleven thousand years ago is prehistoric, but not by very much.  If there once were a ring in the sky, it might still be remembered in legends.  What legends would those be?  They thought maybe dragons?  Snakes?  That ate the sun?  There are lot of legends like that.

Another thing they talked about was how dangerous the Moon might be.  A really important point about Earth rings is that they can't last unless the Moon is active, shooting out rocks or dust or lava occasionally to keep the rings supplied with fresh material, because older material continually falls to Earth.  There aren't long-term stable orbits in the Earth-Moon system.  On one hand, if the Moon isn't active, there's no ring; on the other hand, if there's a ring, the Moon is active.

Could the Moon be active enough to maintain an Earth ring?  Most think the Moon is dead, but my father saw persistent, unresolved difficulties with the idea of a dead Moon (like the fact that people keep seeing red flashes there), and thought that people were settling too easily into a dead-Moon consensus, and ignoring a problem.

Maybe the Moon isn't dead, and if that's the case, we would really want to know about that.  It would be exciting if the Moon erupted and sent a lot of dust and rocks our way, falling into the atmosphere in flames and so on.  It would be just like when the dinosaurs died.  Actually, that's how my father thought the dinosaurs likely did die.  If the Moon were the source of material coming our way, we would get just a few days notice of it.
   Dinosaur hall at Museum of Natural History, DC.  This is their photo.


On a longer time frame, the ring could slowly cycle downward and fall to earth as dust storms.  There's a dinosaur fossil called Oviraptor that was found in the Chinese desert, and what's weird is, the dinosaur was found with its wings spread over its eggs. For all anyone can tell, it appears that the dinosaur just sat there and died for no apparent reason and the sand eventually piled up around it and buried it. There are a lot of other fossils that seem that way (I read about them in The Secret Life of Dust, which has references).

What would make perfect sense out of Oviraptor is if a big dust storm started, and if the dinosaur was used to those, so it spread its wings in protection over its nest, and waited there for the storm to be over.  But this time, the dust storm went on and on and on and on and finally both mother and nest and a lot of other animals of the same kind drowned in sand. There would be no sign of the killer event, because the whole area is sand anyway, due to its long history of similar though smaller events.

Thinking about those things is the origin of this program - an exploration of whether the Earth once had a ring and still might have one today, still driving weather, and while we're at it, remembering that if the Earth has a ring, then the Moon is geologically active and a potential concern - able to launch not only flaming rocks through the atmosphere but also vast dust clouds.  Dust storms that we think of as topsoil moving around, might not be, and sometimes, the storms could be really big.



Still, I believe in Providence, so I think the thing is to be reasonable and assess facts and manage things logically and in the best way we can.

As the book of Wisdom puts it, about a person setting off through the wild waves on an unsound boat, your providence, O Father! guides it, for you have furnished even in the sea a road, and through the waves a steady path, showing that you can save from any danger, so that even one without skill can embark.

That's just about our situation here.  So, onward, rational and fearless.



Next time:  Visit to Newgrange

The laborer being worthy of her hire,