How many full moons would fit in the sky?

[yucina]

Hi all! This is just my curiosity: Since sometimes distances in telescope astronomy are given in the number of full moons that would fit in that distance side by side, I was wondering how many full moons it would take to fill up the whole sky. Thanks!

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Hi all! This is just my curiosity: Since sometimes distances in telescope astronomy are given in the number of full moons that would fit in that distance side by side, I was wondering how many full moons it would take to fill up the whole sky. Thanks! <br />Posted by yucina</DIV><br /><br />Welcome to Space.com!</p><p>It will take a while to figure out the answer to your exact question.</p><p>I can give you one related answer, it would take about 360 Full Moons to make a line from one horizon to the other .</p><p>The "about" in that is because the full moon can vary quite a bit in size depending on whether is is near perigee (closest to the earth) or apogee (furthest away). the difference is more than 20% in size. In general, what I used for the calculation above, is the moon is about half a degree in diameter.</p><p>The "how many to cover the whole sky" will require some time consuming math. I'll answer when I have time to run the calculations if someone doesn't beat me to it.</p> <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>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Hi all! This is just my curiosity: Since sometimes distances in telescope astronomy are given in the number of full moons that would fit in that distance side by side, I was wondering how many full moons it would take to fill up the whole sky. Thanks! <br /> Posted by yucina</DIV></p><p>The sky is a dome above us, and the the arc of the dome going right past us is 180 degrees long stretching from unobstructed horizon to horizon. Full moon is about 0.5 degrees in diameter. </p><p>There would be roughly 360 full moons on an arc going right above us.</p><p>The half sphere above us, the dome, would have the area of (4piR^2) / 2, so if the longest arc of the dome is 180 degrees, the radius R would be 360 / pi / 2 = 57.3 degrees.</p><p>The area of the sky dome would then be 20630 square degrees. One full moon would occupy and area of 0.5 * 0.5 = 0.25 square degrees of the whole sky, so the whole sky with unobstructed horizons could occupy as many as 82520 full moons.&nbsp; </p>

 

[centsworth_II]

<p><font color="#333399"><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>...the whole sky with unobstructed horizons could occupy as many as 82520 full moons.&nbsp; <br /> Posted by aphh</DIV></font><br />And since the Sun is the same size as the Moon as seen from Earth,&nbsp; it would take the same number of suns to fill the sky.&nbsp; </p><p>Can you imagine how hot that would be?!<img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-surprised.gif" border="0" alt="Surprised" title="Surprised" /></p> <div class="Discussion_UserSignature"> </div>

 

[dragon04]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>And since the Sun is the same size as the Moon as seen from Earth,&nbsp; it would take the same number of suns to fill the sky.&nbsp; Can you imagine how hot that would be?! <br /> Posted by centsworth_II</DIV></p><p>Don't forget to take into consideration whether the Moon is at apogee or perigee when it's full. The apparent size differs significantly. </p> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[Mee_n_Mac]

If we're going to be picky then remember the Moon appears more or less as a circle.&nbsp; It's impossible to tile the entire hemisphere (w/o overlapping) and have no voids.&nbsp; So does the question now require us to overlap the full Moons ?&nbsp; I'd say the OP has gotten more than she asked for. <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>