Skip to comments.The Moon's equatorial bulge hints at Earth's early conditions
Posted on 02/15/2018 9:44:00 PM PST by SunkenCiv
Over two centuries ago, Pierre-Simon Laplace, a French physicist and mathematician, noticed that the Moon's equatorial bulge is about 20 times larger than expected. Now, researchers are trying to find out why. Although the Moon looks quite spherical from the ground, it is flatter at its poles and wider at its equator, a trait known as an equatorial bulge. This characteristic is common; it's usually caused by an object's rotation around its axis. However, it's been noted that the Moon's bulge is about 20 times larger than it should be given its rotational rate of once per month... researchers at the University of Colorado Boulder created an innovative model to study the disproportionate bulge and determine the conditions needed for its formation. They found that the bulge formed over hundreds of millions of years during the Hadean time (around 4 billion years ago). However, for the bulge to form this slowly, Earth's tidal forces would have needed to be much weaker than they are today. The weak tidal forces suggest that Earth's water was less mobile -- in other words, frozen -- during this time period. To reach their result, the team assessed how rapidly the Moon could have retreated from Earth, an effect likely caused by the Moon and Earth's tidal and gravitational interactions... Today, the Moon currently recedes from Earth by 4 centimeters each year. However, little is known about the Moon's early recession speed, making it difficult to determine when the bulge formed.
(Excerpt) Read more at astronomy.com ...
Full title: The Moon's equatorial bulge hints at Earth's early conditions -- A frozen Earth may have caused the Moon's abnormally large equatorial diameter.
Wish I could do something about my equatorial bulge.
Apropos of nothing, personal gratification is in fact the only kind there is.
Present-day nautilus shells almost invariably show thirty daily growth lines (give or take a couple) between the major partitions, or septa, in their shells. Paleontologists find fewer and fewer growth lines between septa in progressively older fossils. 420 million years ago, when the moon circled the earth once every nine days, the very first nautiloids show only nine growth lines between septa. The moon was closer to the earth and revolved about it faster, and the earth itself was rotating faster on its axis than it is now. The day had only twenty-one hours, and the moon loomed enormous in the sky at less than half its present distance from earth.
I grok that.
The Moon is just happy to see us, that’s all.
The Moon is just happy to see us, that’s all.
It's the brie..
I've read that a "Snowball Earth", like other "Snowball Planets", would never recover. Reflection of the Sun's energy from its frosty-white surface would prevent...um...Global Warming.
I can see my mining claim site. Thanks to Elon Musk, I just might be able to get my operations up and running.
An inquiry a few years ago indicated that Quaker Oats failed to ensure taxes were collected and the land was claimed by the government.
We need a class action against Quaker Oats to get our land back. I bet there is tons of oil under my square inch.
Our little pea brains thought if we collected enough of them to make a square foot, we could go there some day and stand on our claim.
"However, nobody at Quaker Oats could have anticipated the mass idiocy of American consumers. One guy had over 10,000 deeds and wanted to convert them into one single piece of property that would be a little less than a quarter-acre. And Quaker received thousands of letters from consumers who wanted to mine their 1 square inch for gold. However, mineral rights were not included in the deeds, and if gold would have been discovered, it would not have accrued to the deed holders. And management never paid the fee to record and register the deeds; just imagine the cost of recording 21 million deeds."
Naw ... it’s the biscuits and gravy.
Hey, if Musk could get my Corvette there, I’d go, just to do some prospecting.
“The weak tidal forces suggest that Earth’s water was less mobile — in other words, frozen — during this time period.”
OR perhaps water was tied up in the atmosphere as water vapor. Perhaps this water came down as rain in a short period of time - say 40 days - and flooded the earth.
Except Earth is just big enough to have an radioactive core of molten iron and nickel. Some say the Earth actually consumed another smaller proto-planet that caused enough crustal ejecta to form the moon itself.
The Earth in it’s snowball form had so much activity going on in the mantle and crust that volcanoes below the ice erupted through them and displaced trillions of tons of CO2 in to the atmosphere, warming it enough to expose land that then itself had a warming effect to lower planet-wide reflective albedo.
That is, until some giant alien comes along and pours some kind of flavoring on the ice...
I just had one, the Dark Chocolate flavor; all that’s left now is one Heath and one Double Chocolate (both excellent).
Those lunar rovers still work, and they run on solar cells...
V.A. Firsoff (Valdemar Axel Firsoff, as it turns out), Strange World of the Moon ,published 1959, ten years before the manned landings started, and even before the first robotic landers, is interesting in that it shows the prevailing ideas about what would be found on the Moon (it was already believed during the 19th century, and more relevantly, by the 1920s and 1930s in Germany, that humans would visit the Moon). In a chapter "The Earth's Fair Child or a Foundling?" discusses the concept of the birth of the Moon via an overspin (doesn't use that word) condition on the Earth, which appears to be his view....the Moon clearly could not have been the satellite of the Earth then, for a total period of about 2,000 million years... Spurr points out that the face of the Moon shows two systems of great surface fractures, or faults, lying about 30 degrees from the two poles and trending from west-south-west to east-north-east. This is explained by him as a result of the halting of the Moon's rotation... Curiously, the face of the Earth, too, shows a similar structure, with the same general trend -- the Highland Boundary Fault... The poles of the Earth would also seem to have shifted place on at least three occasions, in the Cambrian, Permian, and (lastly) Quaternary Periods, brining ice and cold to previously warm lands... some mighty force made the crust of the Earth slip (the rotational stability of the axis of a mass as large as the Earth is enormous) and the position of the poles wobbled... there exists on the Moon a triple grid of surface fractures... perpendicular to each other within each grid, the grids being of different ages... Cambrian, Perm-Carboniferous, and Tertiary.Fascinating idea, based though it is on outmoded ideas about impact (i.e., Firsoff's view that there was no role for impact). He's basically given us a snapshot of the problems inherent with a fission origin (either by overspin or by impact), not least of which is that the fission origin also requires in orbit formation of the lunar sphere and capture by the Earth, while showing that capture is possible. He appears to envisage three encounters between the formed Moon and the Earth, resulting in temporary capture twice leading to the eventual outright capture.
Deep thoughts. :)
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