If there was no moon @ 240,000 miles from earth, I was told that the earth would remain in its current orbit but would wobble significantly. Is this true? And if so what effect would you predict would happen to us on this planet?
Mercury and Venus don’t have moons. Mars has two really tiny ones. I’ve never heard that these planets wobble appreciably. Why would earth wobble more than it already does?
It is too clear, and so it is hard to see.
Earth wobbles more than Mars and Venus because the Earth has to put up with politicans who generate both hot air (global warming) and waffling (wobble.)
Earth is already wobbling a lot in its orbit. More than any other planet, except maybe Pluto. Having an oversized moon swinging around it makes it sway from side to side, to keep its balance.
There has to be a better way to say that. Okay, how about this:
The Earth isn’t alone in its orbit. The nice ellipse is defined by the center of mass of the Earth/Moon system. When the Moon is on the Sunside of its path, the Earth has to be out in the other direction by a proportionate distance. If there were no Moon, or if the Moon were as relatively small in comparison to the Earth as the moons of the other planets are, the wobble would be much less pronounced.
The Discovery channel ran a show a few weeks ago called If We Had No Moon. (It’s still listed at tttp://www.discovery.com/sched/domestic/discovery/discovery.html#moon but I don’t think they are running it again.) They covered a lot of theories. One of them was that the Moon makes the Earth more stable and the poles would wander around more if it was not there. (Their conclusion was that the polar caps would not exist and the predominate life forms on Earth would be aquatic.)
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Oops. Typoed the link. Try…
http://www.discovery.com/sched/domestic/discovery/discovery.html#moon
OK, you didn’t really say “yadda yadda yadda.” 
I took “wobble” to refer to Earth changing its orientation is space about its center of mass, not changing its center of mass. Perhaps we can refer to the motion of the center of mass about Earth-Moon center of mass as “wiggling,” so we don’t get them confused. 
So Skeleton, were you talking about wiggling or wobbling?
It is too clear, and so it is hard to see.
We did the no moon thing before here but the main consensus was there would then be no tides. yikes.
In both Isaac Asimov’s “Foundation”, and his “Robots” universes, Earth was the only planet that developed advanced life, and it was because of how big our moon is. As the Earth was forming, the gravitational pull from the moon pulled radioactive elements closer to the surface. Exposing early life to low-level radiation caused mutations to appear more often than they otherwise would, causing quicker evolution.
This is fiction, but are there any scientists that believe the moon increased radiation on the Earth’s surface?
WIGGLING NOT WOBBLING BY YOUR DEFINITION.
WIGGLING NOT WOBBLING BY YOUR DEFINITION.
tanstaafl:
Thank you! I wanted to watch that show, but came in on the last of it. I tried asking others in GD about their reasoning on “no life as we know it”, but no one gave me the polar ice cap scenario. Still can’t say that I agree with it.
JAlan:
I love those books! I even gave them to my daughter to read, and she enjoyed them also. Don’t know if there is any scientific agreement about the increased radiation, but it makes a very credible “foundation” for a sci-fi romp.