A question to ponder:

[vogon13]

On<b> average</b> is the earth or the moon closer to the sun ??<br /><br />Considering the path of the moon about the earth is now known to within inches, a definitive answer to this question must be out there!<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>

 

[dragon04]

Depends on whether apogee is "Sunward" or not. <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[derekmcd]

I could be way off in my thought process here, but I'll give it a shot.<br /><br />I don't think the apogee and perigee of the moon is consistent if you charted it using 360 degrees. I'm pretty sure it either advances or recedes. However, if you charted it over a full cycle and averaged out the plots you recorded, it would form a perfect circle.<br /><br />Thus making them equal in distance on average.<br /><br /><br />But...<br /><br />Enter the gravitation forces of the sun and I would think this would have a small effect on the above mentioned perfect circle. I can only imagine that some tidal and/or gravitation forces between the sun and moon would tend to keep the apogee 'sunward' for a longer period.<br /><br />I vote for the moon, but I could be wrong. <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[MeteorWayne]

I think when you average it all out over a long enough period of time, it's a tie. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

But since that constantly changes, over a long enough time, it should average out.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[alokmohan]

Is not sun too distant?Moon is nextdoor.

 

[dragon04]

<font color="yellow">But since that constantly changes, over a long enough time, it should average out.</font><br /><br />You're probably right. Earth/Moon is a system, and pretty much for all practical purposes would have to be considered as a single body in terms of the Moon's proximity to Earth.<br /><br />But for the fans of minutia, one of the two is "closer". <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[billslugg]

Barycenter orbits barycenter. Barycenter is center of mass. If Earth orbit was circular then Earth and Moon would be in an exact tie. However:<br /><br />If there happened to be a new moon when the Earth was at perigee, and anything other than a full moon at apogee, then the Moon would be closer on average. <div class="Discussion_UserSignature"> <p> </p><p> </p> </div>

 

[MeteorWayne]

But the point of apogee and perigee constantly shift, so while one might be closer now, later it would be the other. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[usn_skwerl]

and taking into the ever present, albeit weak gravity from mars, jupiter, saturn....how would that affect the outcome? <div class="Discussion_UserSignature"> </div>

 

[vogon13]

Yeah, and figuring the <i> average</i> is going to be tricky.<br /><br />We all know the moon can be closer and further from the sun than the earth ever gets, but analyzing all the variables over time is something that just thinking about it gives me a headache.<br /><br />Solar perturbations are going to modify the shape of the moon's path about the earth, and it will also affect the amount of time the moon spends in various segments of it's path.<br /><br />If forced to guess, I would say the moon, <i>on average</i>, is further from the sun than the earth is, but I concede the magnitude of the difference might be measured in centimeters. The concavity of the moons path (when seen from above the ecliptic) might be the salient observation here . . . <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>

 

[nexium]

Suppose we draw a line though the center of the moon to the center of the Earth. Every 4 weeks the sun is exactly at a 90 degree angle to the line. At this time = 50%, the Earth and moon CENTERS are equal distant from the Sun, but the Earth has a larger radius, so the closest point on the Earth is closer to the Sun by the difference in the radii = about 1300 miles; so on the average the Earth is closer, unless you insist on the center of Earth. Neil

 

[MeteorWayne]

That's a pretty good argument!! <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>