Difference between revisions of "June 13, 2004"

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=Mercy, Mersenius!=
 
=Mercy, Mersenius!=
 
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          <td><h2 align="left">Mercy, Mersenius!</h2></td>
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          <td><h2 align="right">June 13, 2004</h2></td>
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<div align="center">   [[File:LPOD-2004-06-13.jpeg|LPOD-2004-06-13.jpeg]]<br>
      <table width="640"  border="0" align="center" cellpadding="6" cellspacing="2">
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<span class="main_sm">Image Credit: [mailto:benoit_schillings@yahoo.com Benoit Schillings]</span>
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  <div align="center">   <IMG SRC="images/LPOD-2004-06-13.jpeg" name="Pic1But" width="557" height="400" border="0"><br>
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</table>
  <span class="main_sm">Image Credit: <A class="one" HREF="mailto:benoit_schillings@yahoo.com">Benoit Schillings</A></span>
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<table class="story" border="0" bgcolor="#FFFFFF" width="90%" cellpadding="10" align="center">
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<tr>
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<td><p class="Story" align="center"><b>Mercy, Mersenius!</b></p>
</table>
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<p class="story" align="left">
        <p>
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Mersenius is in the second rank of lunar craters. Not a must-see like Copernicus, Plato or Gassendi, but a good
<table class="story" border="0" bgcolor="#FFFFFF" width="90%" cellpadding="10" align="center">
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crater with more interesting features than are obvious. Mersenius is 84 km wide and about 2.3 km deep. But as has
        <tr>
+
been known for more than 125 years, Mersenius appears to have a domed floor so its depth may be more varied than  
          <td><p class="Story" align="center"><b>Mercy, Mersenius!</b></p>
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for normal craters. In his 1876 book, <I>The Moon</I>, Neison quoted Schmidt as saying that Mersenius had a  
            <p class="story" align="left">
+
"strongly-convex" floor and estimated its center to be 450 m higher than near the walls. This remarkable low sun  
Mersenius is in the second rank of lunar craters. Not a must-see like Copernicus, Plato or Gassendi, but a good
+
image by Benoit Schillings gives little evidence for a gradually decreasing elevation westward from the center  
        crater with more interesting features than are obvious. Mersenius is 84 km wide and about 2.3 km deep. But as has
+
of the floor, but does show a shadow/depression where the west wall meets the floor. It seems unlikely that this  
        been known for more than 125 years, Mersenius appears to have a domed floor so its depth may be more varied than  
+
alone is 450 m of relief, but then all these shadow measurements are ancient - are there no modern measurements  
        for normal craters. In his 1876 book, <I>The Moon</I>, Neison quoted Schmidt as saying that Mersenius had a  
+
of this crater's geometry? The line of overlapping craters on the floor are aligned with Imbrium, and thus may be
        "strongly-convex" floor and estimated its center to be 450 m higher than near the walls. This remarkable low sun  
+
distant secondaries from that basin-forming impact. The image also reveals more delicate rilles on the crater's  
        image by Benoit Schillings gives little evidence for a gradually decreasing elevation westward from the center  
+
floor than I have seen on any other Earth-based image. These are very difficult to image or observe - even the  
        of the floor, but does show a shadow/depression where the west wall meets the floor. It seems unlikely that this  
+
Great Schmidt of Athens saw only two, and they were "very difficult." Small pyroclastic  
        alone is 450 m of relief, but then all these shadow measurements are ancient - are there no modern measurements  
+
[../../../LPOD-2004-02-10.htm deposits] have also been detected around the rilles.  
        of this crater's geometry? The line of overlapping craters on the floor are aligned with Imbrium, and thus may be
+
Mersenius must be another floor-fractured [../../../LPOD-2004-02-10.htm crater].</p>
        distant secondaries from that basin-forming impact. The image also reveals more delicate rilles on the crater's  
+
<p><b>Technical Details: </b><br>
        floor than I have seen on any other Earth-based image. These are very difficult to image or observe - even the  
+
Taken with an 18 inch F/4.5 newtonian, double barlow with a firewire 640x480 camera; combination of  
        Great Schmidt of Athens saw only two, and they were "very difficult." Small pyroclastic  
+
about 150 frames. Image processing (image registrration etc...) done with home-made software which  
        [../../../LPOD-2004-02-10.htm deposits] have also been detected around the rilles.  
+
on top of doing frame selection and alignement, distorts the images to counter the distortion induce
        Mersenius must be another floor-fractured [../../../LPOD-2004-02-10.htm crater].</p>
+
by the seeing - this helps a lot for the image quality. With a normal regular best fit stack, you  
<p><b>Technical Details: </b><br>
+
will always have a better resolution at or near the registration point. My algorithm does a  
            Taken with an 18 inch F/4.5 newtonian, double barlow with a firewire 640x480 camera; combination of  
+
distortion of the whole image to get an overall best fit for the whole image, not just for a single  
                    about 150 frames. Image processing (image registrration etc...) done with home-made software which  
+
point. </p>
                    on top of doing frame selection and alignement, distorts the images to counter the distortion induce
+
<p class="story" align="left"><i>Originally posted April 3, 2004 </i></p>
                    by the seeing - this helps a lot for the image quality. With a normal regular best fit stack, you  
+
<p class="story" align="left"><b>Related Links:</b><br>
                    will always have a better resolution at or near the registration point. My algorithm does a  
+
[http://www.astrosurf.com/benoit/#PLimages Benoit Schillings Web Page]<br>
                    distortion of the whole image to get an overall best fit for the whole image, not just for a single  
+
[http://www.lpi.usra.edu/research/lunar_orbiter/images/img/iv_149_h1.jpg Lunar Orbiter View]
                    point. </p>
+
</p>
<p class="story" align="left"><i>Originally posted April 3, 2004 </i></p>
+
<p class="story"><b>Tomorrow's LPOD:</b> Cassini</p>
            <p class="story" align="left"><b>Related Links:</b><br>
+
</tr>
[http://www.astrosurf.com/benoit/#PLimages Benoit Schillings Web Page]<br>
+
</table>
[http://www.lpi.usra.edu/research/lunar_orbiter/images/img/iv_149_h1.jpg Lunar Orbiter View]
+
<hr width="640" align="center">
    </p>
+
<p align="center" class="main_titles"><b>Author &amp; Editor:</b><br>
            <p class"story"><b>Tomorrow's LPOD:</b> Cassini</p>
+
[mailto:tychocrater@yahoo.com Charles A. Wood]</p>
              <p><img src="../../../MainPage/spacer.gif" width="640" height="1"></p></td>
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<p align="center" class="main_titles"><b>Technical Consultant:</b><br>
        </tr>
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[mailto:anthony@perseus.gr Anthony Ayiomamitis]</p>
      </table>
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<p align="center" class="main_titles"><b>A service of:</b><br>
      <hr width="640" align="center">
+
[http://www.observingthesky.org/ ObservingTheSky.Org]</p>
 
+
<p align="center" class="main_titles"><b>Visit these other PODs:</b> <br>
      <p align="center" class="main_titles"><b>Author &amp; Editor:</b><br>
+
[http://antwrp.gsfc.nasa.gov/apod/astropix.html Astronomy] | [http://www.msss.com/ Mars] | [http://epod.usra.edu/ Earth]</p>
          [mailto:chuck@observingthesky.org Charles A. Wood]</p>
 
      <p align="center" class="main_titles"><b>Technical Consultant:</b><br>
 
          [mailto:anthony@perseus.gr Anthony Ayiomamitis]</p>
 
      <p align="center" class="main_titles"><b>[mailto:webmaster@entropysponge.com Contact Webmaster]</b></p>
 
      <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>
 
 
 
 
<p>&nbsp;</p>
 
<p>&nbsp;</p>
 
 
 
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===COMMENTS?===  
 
===COMMENTS?===  
 
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Revision as of 18:21, 4 January 2015

Mercy, Mersenius!

LPOD-2004-06-13.jpeg

Image Credit: Benoit Schillings

Mercy, Mersenius!

Mersenius is in the second rank of lunar craters. Not a must-see like Copernicus, Plato or Gassendi, but a good crater with more interesting features than are obvious. Mersenius is 84 km wide and about 2.3 km deep. But as has been known for more than 125 years, Mersenius appears to have a domed floor so its depth may be more varied than for normal craters. In his 1876 book, The Moon, Neison quoted Schmidt as saying that Mersenius had a "strongly-convex" floor and estimated its center to be 450 m higher than near the walls. This remarkable low sun image by Benoit Schillings gives little evidence for a gradually decreasing elevation westward from the center of the floor, but does show a shadow/depression where the west wall meets the floor. It seems unlikely that this alone is 450 m of relief, but then all these shadow measurements are ancient - are there no modern measurements of this crater's geometry? The line of overlapping craters on the floor are aligned with Imbrium, and thus may be distant secondaries from that basin-forming impact. The image also reveals more delicate rilles on the crater's floor than I have seen on any other Earth-based image. These are very difficult to image or observe - even the Great Schmidt of Athens saw only two, and they were "very difficult." Small pyroclastic [../../../LPOD-2004-02-10.htm deposits] have also been detected around the rilles. Mersenius must be another floor-fractured [../../../LPOD-2004-02-10.htm crater].

Technical Details:
Taken with an 18 inch F/4.5 newtonian, double barlow with a firewire 640x480 camera; combination of about 150 frames. Image processing (image registrration etc...) done with home-made software which on top of doing frame selection and alignement, distorts the images to counter the distortion induce by the seeing - this helps a lot for the image quality. With a normal regular best fit stack, you will always have a better resolution at or near the registration point. My algorithm does a distortion of the whole image to get an overall best fit for the whole image, not just for a single point.

Originally posted April 3, 2004

Related Links:
Benoit Schillings Web Page
Lunar Orbiter View

Tomorrow's LPOD: Cassini


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.