Difference between revisions of "March 22, 2004"

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=Double Planet=
 
=Double Planet=
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      <td width="50%"><h2 align="left">Double Planet</h2></td>
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  <td width="50%"><h2 align="right">March 22, 2004</h2></td>
 
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[[File:LPOD-2004-03-22.gif|LPOD-2004-03-22.gif]]</div>
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      <td><div align="center" span class="main_sm">Image Credit:  <a class="one" href="http://www2.jpl.nasa.gov/galileo/earthmo2.html">Galileo Mission</a></div></td>
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<td><div align="center" span class="main_sm">Image Credit:  [http://www2.jpl.nasa.gov/galileo/earthmo2.html Galileo Mission]</div></td>
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<p class="story" align="center"><b>Double Planet </b></p>
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  <p class="story" align="center"><b>Double Planet </b></p>
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<p class="story" align="left">
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The origin of the Moon was long a mystery. Most scientists now accept the giant impact  
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  <p class="story" align="left">
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[LPOD-2004-03-12.htm model] but one of the earlier ideas was that the Earth and Moon formed at the  
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          The origin of the Moon was long a mystery. Most scientists now accept the giant impact  
+
same time from the same region of the solar nebula. However, this sister planet or double planet theory could not  
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        [LPOD-2004-03-12.htm model] but one of the earlier ideas was that the Earth and Moon formed at the  
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explain why, if the two worlds formed of the same material, the Earth has a massive iron core and a density of  
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        same time from the same region of the solar nebula. However, this sister planet or double planet theory could not  
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5.5 g/cc while the Moon has only a small amount of iron and a resulting density of only 3.3 g/cc. The double  
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        explain why, if the two worlds formed of the same material, the Earth has a massive iron core and a density of  
+
planet theory is dead, but the Earth-Moon system does look like a double planet because the Moon is relatively  
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        5.5 g/cc while the Moon has only a small amount of iron and a resulting density of only 3.3 g/cc. The double  
+
large compared to the Earth: their diameters are 3,476 km and 12,756 km. And like a contrasting double star pair,  
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        planet theory is dead, but the Earth-Moon system does look like a double planet because the Moon is relatively  
+
the colors of our two worlds are strikingly different - we must be one of the most wonderful sights in the solar  
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        large compared to the Earth: their diameters are 3,476 km and 12,756 km. And like a contrasting double star pair,  
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system! </p>
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        the colors of our two worlds are strikingly different - we must be one of the most wonderful sights in the solar  
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<p><b>Technical Details:</b><br>
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        system! </p>
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The Galileo spacecraft took this image in 1992 while swinging close to Earth for a gravitational  
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push towards Jupiter. The Moon is actually in the foreground moving from left to right around the  
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  <p><b>Technical Details:</b><br>
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Earth. The JPL web site says that contrast and color of both Earth and Moon were enhanced, but  
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the Moon looks yellower to me than it actually is. However, the image was taken not through a green  
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The Galileo spacecraft took this image in 1992 while swinging close to Earth for a gravitational  
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filter that mimics our eyes sensitivity, but with violet, red and infrared filters and may be  
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push towards Jupiter. The Moon is actually in the foreground moving from left to right around the  
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correct for this combination. </p>
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Earth. The JPL web site says that contrast and color of both Earth and Moon were enhanced, but  
+
<p class="story"><b>Related Links:</b><br>
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the Moon looks yellower to me than it actually is. However, the image was taken not through a green  
 
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filter that mimics our eyes sensitivity, but with violet, red and infrared filters and may be  
 
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correct for this combination. </p>
 
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  <p class"story"><b>Related Links:</b><br>
 
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[http://www2.jpl.nasa.gov/galileo/mission_end.html Galileo mission overview]<br>
 
[http://www2.jpl.nasa.gov/galileo/mission_end.html Galileo mission overview]<br>
 
[http://www.lpl.arizona.edu/outreach/origin/ The Origin of the Moon]</p>
 
[http://www.lpl.arizona.edu/outreach/origin/ The Origin of the Moon]</p>
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<p class="story"> <b>Tomorrow's LPOD:</b> Magnificent Moon!</p>
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  <p class"story"> <b>Tomorrow's LPOD:</b> Magnificent Moon!</p>
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<p align="center" class="main_titles"><b>Author & Editor:</b><br>
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[mailto:tychocrater@yahoo.com Charles A. Wood]</p>
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<p align="center" class="main_titles"><b>Technical Consultant:</b><br>
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[mailto:anthony@perseus.gr Anthony Ayiomamitis]</p>
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<p align="center" class="main_titles"><b>A service of:</b><br>
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    <tr>
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[http://www.observingthesky.org/ ObservingTheSky.Org]</p>
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      <td>
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<p align="center" class="main_titles"><b>Visit these other PODs:</b> <br>
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  <p align="center" class="main_titles"><b>Author & Editor:</b><br>
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[http://antwrp.gsfc.nasa.gov/apod/astropix.html Astronomy] | [http://www.msss.com/ Mars] | [http://epod.usra.edu/ Earth]</p></td>
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      [mailto:chuck@observingthesky.org Charles A. Wood]</p>
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      <p align="center" class="main_titles"><b>Technical Consultant:</b><br>
 
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      [mailto:anthony@perseus.gr Anthony Ayiomamitis]</p>
 
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      <p align="center" class="main_titles"><b>[mailto:webmaster@entropysponge.com Contact Webmaster]</b></p>
 
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      <p align="center" class="main_titles"><b>A service of:</b><br>
 
−
      <a class="one" href="http://www.observingthesky.org/">ObservingTheSky.Org</a></p>
 
−
      <p align="center" class="main_titles"><b>Visit these other PODs:</b> <br>
 
−
      <a class="one" href="http://antwrp.gsfc.nasa.gov/apod/astropix.html">Astronomy</a> | <a class="one" href="http://www.msss.com/">Mars</a> | <a class="one" href="http://epod.usra.edu/">Earth</a></p></td>
 
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===COMMENTS?===  
 
===COMMENTS?===  
 
Click on this icon [[image:PostIcon.jpg]] at the upper right to post a comment.
 
Click on this icon [[image:PostIcon.jpg]] at the upper right to post a comment.

Revision as of 17:17, 4 January 2015

Double Planet

LPOD-2004-03-22.gif
Image Credit: Galileo Mission

Double Planet

The origin of the Moon was long a mystery. Most scientists now accept the giant impact [LPOD-2004-03-12.htm model] but one of the earlier ideas was that the Earth and Moon formed at the same time from the same region of the solar nebula. However, this sister planet or double planet theory could not explain why, if the two worlds formed of the same material, the Earth has a massive iron core and a density of 5.5 g/cc while the Moon has only a small amount of iron and a resulting density of only 3.3 g/cc. The double planet theory is dead, but the Earth-Moon system does look like a double planet because the Moon is relatively large compared to the Earth: their diameters are 3,476 km and 12,756 km. And like a contrasting double star pair, the colors of our two worlds are strikingly different - we must be one of the most wonderful sights in the solar system!

Technical Details:
The Galileo spacecraft took this image in 1992 while swinging close to Earth for a gravitational push towards Jupiter. The Moon is actually in the foreground moving from left to right around the Earth. The JPL web site says that contrast and color of both Earth and Moon were enhanced, but the Moon looks yellower to me than it actually is. However, the image was taken not through a green filter that mimics our eyes sensitivity, but with violet, red and infrared filters and may be correct for this combination.

Related Links:
Galileo mission overview
The Origin of the Moon

Tomorrow's LPOD: Magnificent Moon!

Author & Editor:
Charles A. Wood

Technical Consultant:
Anthony Ayiomamitis

A service of:
ObservingTheSky.Org

Visit these other PODs:
Astronomy | Mars | Earth

 

COMMENTS?

Click on this icon File:PostIcon.jpg at the upper right to post a comment.

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