Moons

[bdewoody]

I saw on the Science channel that if the earth had no moon our rotational axis would wobble radically drastically affecting the weather. If this is so why don't we see this with Mars and Venus? <div class="Discussion_UserSignature"> <em><font size="2">Bob DeWoody</font></em> </div>

 

[vogon13]

IIRC, over long periods of time, Mars' axis does tilt from 15 to 40 degrees.<br /><br />Venus, whose orbit around the sun being very circular (and it being a slow rotator too) may be spared, although, considering how brief a time has passed since the surface (and presumably it's orientation) was imaged, are we so sure it doesn't, either?<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[Boris_Badenov]

Vogon, Eddie, Signs of intelligence!!! I take back all those nasty things I said about you!!! <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[harmonicaman]

I believe all orbiting bodies are in a life-long stilled to attain a rotational harmonic equilibrium with their gravitational partners. Since the Earth and Moon have a very close gravitational relationship, they are quickly coming into equilibrium.<br /><br />(The Moon currently has its most massive side tidally locked on the Earth and it's steadily moving to a position in space where the Earth will always present the same face to the moon -- the Earth and Moon will some day orbit at a 1:1 harmonic equilibrium.)<br /><br />Eventually; the Earth and Moon system will also become tidally locked to the Sun. This is currently the case with planet Mercury, which has obtained a curious 3:2 harmonic spin-orbit around the Sun. This seems to indicate that the closer the gravitational connection, the faster the tidal locking occurs. <br /><br />Since Mars and Venus have not obtained a tidal lock on the Sun (yet) and do not possess a large moon with which to harmonize their orbits; they cannot have a completely stable rotational axis.<br /><br />I also think that the phenomenon of tidal locking plays a role in causing accretion discs to coordinate themselves and form Solar Systems.

 

[minotast]

"I saw on the Science channel that if the earth had no moon our rotational axis would wobble radically drastically affecting the weather. If this is so why don't we see this with Mars and Venus?"<br /><br />Mars does have a tilted axis and Venus has a retrograded axis. I believe as humans we like to exaggerate how little we know of what may occur to things we don't even have the chance of observing with our own eyes. <br /><br />I believe since there is no evidence to go either way on this that planets originally stay in a constant degree axis of a 0 tilt, until acted upon by another object. Like an asteroid collision. That might explain why Venus, the Earth, and Mars have tilted axis. Because after all the Earth has been hit my asteroids for so many times during it's history and so has nearly everything else for that matter. But without the moon after such a collision the earth would just wobble about uncontrollably until it has some weird like tilt to it's axis like Venus. But this all depends on the impact the collision had on the planet and how much of a gravitational effect it has with it's moons. Uranus and Saturn have wild tilted axises, but their moons are too small to controll and maintain the axis of that planet. <br /><br />But this is my own humble opinion. It could be that moons and their gravity have no effect on the tilt of a planet at all. And such information was created by same people that thought they were abducted by space aliens or throught they saw the tooth fairy one night. Some people will DO ANYTHING for attention and money.<br /><br />"IIRC, over long periods of time, Mars' axis does tilt from 15 to 40 degrees. "<br /><br />Sorry but has time travel been invented yet? There is no way for sure on determining Mars has a constantly tilting axis other than by constant meteor impacts. <br /><br />"Indeed, since it's rotation is retrograde, Venus may have completely flipped over and is now rotating backwards, compared to the other planets....and may do so a

 

[vogon13]

Mercury is a special case. It exhibits spin/orbit coupling. Mercury rotates on it's axis 3 times for every 2 revolutions around the sun it makes.<br /><br />{think I said that right <img src="/images/icons/laugh.gif" /> }<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[vogon13]

(That's why even though Mariner 10 made 3 useful flybys of Mercury, it always photographed the same features oriented to the sun the same way, Mariner 10's orbit took it back to Mercury every 176 days, twice Mercury's period of revolution around the sun, and 3 turns of Mercury upon its' axis. Messenger will eventually orbit Mercury and photograph everything)<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[brellis]

when I saw the topic "Moons" posted by "Vogon" I was preparing myself for a gruesome survey of plumbers' cracks <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[minotast]

"Mercury is a special case. It exhibits spin/orbit coupling."<br /><br />They don't actually couple. They aren't exactly equal, just live Venus isn't exactly equal with how long a day and a year are.<br /><br />"Mercury rotates on it's axis 3 times for every 2 revolutions around the sun it makes." <br /><br />Actually it is more like 38 to 25, than three to two. So it roughly rotates on it's axis 38 times for every 25 revolutions around the sun. <br /><br />By the way you shouldn't double post.

 

[brellis]

Boris, this proves that the sun shines even on a <b> dog's </b> Moon! <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[3488]

I heard somewhere that eventaully the Earth & moon will be locked together in rotation (much like Pluto & Charon), but in a period of about 48 DAYS & the Earth's axis will eventually turn upright (no tilt, hence no seasons). Imagine that. <br /><br />Bearing in mind that the sun will be considerably more powerful then, than it is now, I would suspect the climate on Earth will be inhospitable, very hot. At this point, the sun anyway is expected to swell into a red giant. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[pioneer0333]

From what I remember, the moon is slowly leaving Earth. The distance is about 1 inch per year. With this in mind, how long will it take before signs of a noticeable change in Earths gravitational spin occur? What I'm asking is, how far does the moon has to be from Earth to stop or change Earths current spin on it's axis? <div class="Discussion_UserSignature"> </div>

 

[doubletruncation]

<font color="yellow">From what I remember, the moon is slowly leaving Earth. The distance is about 1 inch per year. With this in mind, how long will it take before signs of a noticeable change in Earths gravitational spin occur? What I'm asking is, how far does the moon has to be from Earth to stop or change Earths current spin on it's axis?</font><br /><br />The Earth's rotation rate changes as the moon moves away from the Earth (the lost angular momentum from the Earth's spin goes into angular momentum of the moon's orbit). The rate at which the Earth's rotation is decreasing currently is about 2 milliseconds per century. If the Earth continued to slow down at this rate then it would be locked ~4 billion years from now, but the slowing rate decreases as the moon moves away from the Earth (the strength of the tides decreases). Also note that it's difficult to forecast exactly how this rate will continue into the future because it is determined largely by the extent of the tidal bulge raised on the Earth by the moon and by the friction forces as the bulge moves around the Earth. That depends very much on how the landmasses are distributed over the surface of the Earth (which changes due to plate tectonics). Due to the current size of the pacific ocean basin (it takes 12 hours for a wave to travel from one side to the other and back) the rotation rate of the Earth is currently slowing at an enhanced rate (if you extrapolate backwards with the current rate, the Earth's day would have been very short 4 billion years ago!). There are some good discussions of this topic on Cornell's "Ask an Astronomer" website:<br />http://curious.astro.cornell.edu/question.php?number=124<br />http://curious.astro.cornell.edu/question.php?number=700 <div class="Discussion_UserSignature"> </div>

 

[minotast]

"I'm sorry, but you are mistaken. There are very accurate ways to determine the obliquity cycle of the Martian rotational axis, which varies from 15 to 35 degrees over a 124,000 year period."<br /><br />From our primitive technology and understanding of the Universe?<br /><br />Don't get ahead of yourself there or I just might off the Earth...<br /><br />We are not advance enough in our understanding of the universe to truely know these things as of yet. <br /><br />We can base theories and regard these theories as facts. But they are far from facts until they actually proven. <br /><br />Does anyone remember what proof is huh? Or am I the only one?<br /><br />"Some recent studies even suggest that over many millions of years, the swing may be as much as 0 to 60 degrees."<br /><br />Ah huh... maybe I should jump onto this magic time traveling vehicle and see for myself? <br /><br />I'm sorry but you are the one mistaken and so easily mistakened. We don't know anything or hardly anything. As our planet is to the universe, the amount of information that we know about it is vasting insignificant. Especially when it comes to places we haven't yet step foot on. <br /><br />I mean where are they getting this crap from? The two moons? Our moon? The rovers? Our soil? Our worms? The sun? The black hole in the center of the galaxy? The black hole in the center of the universe that hasn't yet been discovered by the primitive human species? The radiowaves being sent by far away galaxies that this primitive species has yet take a glimps of? The far too away realization that perhaps radio waves from stars in our own galaxy are now millions of light years from us? The tiny dark matter partical that zoom right by ya? What really? I'm not trying to troll by the way... I'm just showwing just how much of an interest I have in this "factual" information that you are so eager to confirm as being legit.<br /><br />But I can agree that perhaps Mars has been hit by asteroids and these asteroids are contributi

 

[vogon13]

I gather jatslo is back . . . . . . <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[vogon13]

<img src="/images/icons/laugh.gif" /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[Boris_Badenov]

" No, I've had enough....it's easier just to dismiss you as a crank and ignore you from now on, which is what I plan to do. "<br /><br />You took the words right out of my mouth!!!<br /> <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[minotast]

But sir.... You are trolling, flaming, and harassments are not going to amount to anything.<br /><br />Do you seriously think the moderators will ban me clearly for stating what I have? I'm sorry but did you actually graduate from college? I know my use of grammar is a bit hard to understand for people that are still in high school or perhaps in elementary school. Which is because I do use a lot of terms that are hard to understand if you can't figure out their meaning. Like atrocious for instance<br /><br />Sheesh... Well now, I am finish dealing with your senseless nature... You have proven that you know as little about astronomy as you know about causality. Which is to say smaller than a quark... Oh, I'm sorry is my use of language still offending you. <br /><br />By the way, I am deeply sorry for hurting your feelings. I know it was wrong of me to criticize your information, even though there is nothing on it that can truly be supporting legit facts. So... have a nice day...<br />

 

[Boris_Badenov]

Are you capable of speaking coherently? How about using spellchecker? <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[minotast]

I think you are implying a grammar checker... <br /><br />Some spell checkers are insufficient in terms of examining and correcting incoherent sentences. <br /><br />By the way, I have a physical disability involving my fingers, known as cerebral palsy. Therefore, it is not wise to use such discriminating tone against me. You do understand, right?

 

[Boris_Badenov]

I have a physical disability too, I only have 1 hand. It does not stop me from being a Chef, or using spellchecker!!! <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[minotast]

"I have a physical disability too, I only have 1 hand. It does not stop me from being a Chef, or using spellchecker!!!"<br /><br />I can obviously see you do not have one hand. Because your coherent behavior is indicating that, you in fact are being unreasonable.<br /><br />Incidentally, if you bother to use a spell checker, you would realize that making more than one exclamation mark is a critical grammar error. The same issue is also involved with using numbers for words. <br /><br />Cannot humans make such mistakes ever so regularly?

 

[Boris_Badenov]

You are right, my complaint with you is not your bad grammar, or your bad spelling, it is your bad behavior. You are a JERK!!! <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[minotast]

The behavior that I demonstrate situates not on promoting the irrational behavior of others. Therefore, you sir need to calm down. All I want is for people to think rationally.