Difference between revisions of "September 25, 2019"

From LPOD
Jump to: navigation, search
(Created page with "__NOTOC__ =Capelling Gash= Originally published June 13, 2010 <!-- Start of content --> <!-- ws:start:WikiTextHeadingRule:1:<h1> --> <!-- ws:start:WikiTextLocalImag...")
 
 
Line 1: Line 1:
 
__NOTOC__
 
__NOTOC__
=Capelling Gash=
+
=More Rilles And Fewer=
Originally published June 13, 2010
+
Originally published May 14, 2010
 
<!-- Start of content -->
 
<!-- Start of content -->
 
<!-- ws:start:WikiTextHeadingRule:1:&lt;h1&gt; -->
 
<!-- ws:start:WikiTextHeadingRule:1:&lt;h1&gt; -->
<!-- ws:start:WikiTextLocalImageRule:16:&lt;img src=&quot;/file/view/LPOD-June13-10.jpg/148539981/LPOD-June13-10.jpg&quot; alt=&quot;&quot; title=&quot;&quot; /&gt; -->[[File:LPOD-June13-10.jpg|LPOD-June13-10.jpg]]<!-- ws:end:WikiTextLocalImageRule:16 --><br />
+
<!-- ws:start:WikiTextLocalImageRule:16:&lt;img src=&quot;/file/view/LPOD-May14-10.jpg/141907215/LPOD-May14-10.jpg&quot; alt=&quot;&quot; title=&quot;&quot; /&gt; -->[[File:LPOD-May14-10.jpg|LPOD-May14-10.jpg]]<!-- ws:end:WikiTextLocalImageRule:16 --><br />
<em>image by [mailto:starman2@allegiance.tv Wes Higgins], Oklahoma</em><br />
+
<em>LRO wide angle camera (WAC) image from [http://lroc.sese.asu.edu/news/index.php?/archives/220-Mare-Frigoris-Constellation-Region-of-Interest.html LRO Featured Images]. Image number M119673851ME [NASA/GSFC/Arizona State University]. (Ignore the white lines - they mark something less interesting than these rilles)</em><br />
 
<br />
 
<br />
Capella and the valley that crosses it appear to be among those rare lunar objects that have been little studied, and thus are a joy. Like Atlas and Hercules, Capella is virtually always seen with its near neighbor Isidorus. Both are older, smooth-walled craters, with Isidorus floored by some smooth material and punctured by a bright simple crater. Capella is more interesting because is appears to have a broad, almost domical and floor-filling central peak, similar to that of [https://the-moon.us/wiki/Alpetragius Alpetragius]. The most captivating feature of Capella, however, is the valley that transects it. This Capella Valley - at least 115 km long (and not [https://the-moon.us/wiki/Vallis_Capella 49 km]) - is actually a crater chain, perhaps a smaller version of the [[July_23,_2008|Rheita Valley]]. The Capella Valley is presumaably also an impact basin secondary crater chain, but what is its source? The secondary craters decrease in size from northwest of Capella to its southeast side, so the source is along the trace of the valley to the northwest. They didn't come from Nectaris - to the south - but the line of the chain is roughly radial to the Imbrium Basin. &quot;Roughly&quot; because its hard to track accurately a trace around more than a thousand kilometers of the Moon; it is about tangent to Serenitatis and seems to graze the eastern half of Imbrium. This direction is similar to the nearby [http://www.lpod.org/?m=20061005 Gutenberg Rilles] suggesting they may have a related formation.<br />
+
The Sheepshanks Rille is hard to observe because it runs approximately E-W and thus casts few shadows. It is just north of the dark lavas of Mare Frigoris in lighter hued plains that have been [http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1822.pdf considered] either impact eject or older mare volcanism, lightened by highlands ejecta. I think these thin, delicate and cratered-upon rilles favor the covered mare lavas interpretation. In [http://www.lpod.org/archive/LPOD-2005-02-13.htm telescopic] and [http://www.lpi.usra.edu/resources/lunar_orbiter/images/img/iv_092_h1.jpg Lunar Orbiter IV] images essentially only the main rille (the topmost one here) is readily visible so this LRO scene reveals rille segments that were at a minimum poorly known. The main rille in the area between the two large craters has one or two interruptions where the surface materials are continuous across the rille. This is most reasonably interpreted as a lava tube whose roof has collapsed everywhere except for these two areas. The narrower and shallower rilles to the south are also not everywhere continuous suggesting they also originated as lava tubes. The lava tube origin, if correct, further buttresses the argument that the light plains here are volcanics. In comparing this image with one from Lunar Orbiter IV it appears that faint rille segments probably connect the Sheepshanks rilles to the [https://the-moon.us/wiki/Rima_Gartner Gärtner Rille] to the east. I was going to say that testing this speculation will be possible with further release of LRO WAC images to the east, but I see that 16 year old Clementine [http://www.mapaplanet.org/explorer-bin/explorer.cgi?map=Moon&amp;layers=moon_clementine_multi&amp;west=24.20&amp;south=56.55&amp;east=38.20&amp;north=60.81&amp;center_lat=0&amp;center=31.2&amp;defaultcenter=on&amp;grid=none&amp;stretch=auto&amp;projection=SIMP&amp;r=5&amp;g=3&amp;b=1&amp;advoption=YES&amp;info=NO&amp;resolution=64&amp;scale=0.23690&amp;imageTopX=-106013.2842510939&amp;imageTopY=1811464.9788290262 data] already confirm it! Hmm, what do we do with a rille whose two ends have different names?<br />
 
<br />
 
<br />
 
<em>[mailto:tychocrater@yahoo.com Chuck Wood]</em><br />
 
<em>[mailto:tychocrater@yahoo.com Chuck Wood]</em><br />
<br />
 
<strong>Technical Details</strong><br />
 
11-05-09, 10:01 UT. 18 Inch Reflector + 4x Powermate barlow + Infinity 2-1M camera; 47 frames, 3325 MAP Points<br />
 
Avistack , Registax V5 , ImagesPlus , Photoshop CS4<br />
 
 
<br />
 
<br />
 
<strong>Related Links</strong><br />
 
<strong>Related Links</strong><br />
Rükl plate [https://the-moon.us/wiki/R%C3%BCkl_47 47]<br />
+
Rükl plate [https://the-moon.us/wiki/R%C3%BCkl_5 5]<br />
Full [http://www.higginsandsons.com/astro/Pictures-iin-templets/Capella-Isidorus-11-05-09.htm frame] image from Wes' website<br />
+
The GLR group published a paper on this rille but I do not have a copy to see what they discovered: Raffaello Lena , KC Pau and Piergiovanni Salimbeni. 2004. Observations of the Rima Sheepshanks. <em>Selenology 23</em>, 1.<br />
 
<br />
 
<br />
<p><b>Yesterday's LPOD:</b> [[September 24, 2019|Straightening the Circle]] </p>
+
<p><b>Yesterday's LPOD:</b> [[September 24, 2019|Basinal Surprises]] </p>
<p><b>Tomorrow's LPOD:</b> [[September 26, 2019|Wobble]] </p>
+
<p><b>Tomorrow's LPOD:</b> [[September 26, 2019|Passing of a Friend]] </p>
 
<hr />
 
<hr />
 
<table class="wiki_table">
 
<table class="wiki_table">

Latest revision as of 02:09, 25 September 2019

More Rilles And Fewer

Originally published May 14, 2010 LPOD-May14-10.jpg
LRO wide angle camera (WAC) image from LRO Featured Images. Image number M119673851ME [NASA/GSFC/Arizona State University]. (Ignore the white lines - they mark something less interesting than these rilles)

The Sheepshanks Rille is hard to observe because it runs approximately E-W and thus casts few shadows. It is just north of the dark lavas of Mare Frigoris in lighter hued plains that have been considered either impact eject or older mare volcanism, lightened by highlands ejecta. I think these thin, delicate and cratered-upon rilles favor the covered mare lavas interpretation. In telescopic and Lunar Orbiter IV images essentially only the main rille (the topmost one here) is readily visible so this LRO scene reveals rille segments that were at a minimum poorly known. The main rille in the area between the two large craters has one or two interruptions where the surface materials are continuous across the rille. This is most reasonably interpreted as a lava tube whose roof has collapsed everywhere except for these two areas. The narrower and shallower rilles to the south are also not everywhere continuous suggesting they also originated as lava tubes. The lava tube origin, if correct, further buttresses the argument that the light plains here are volcanics. In comparing this image with one from Lunar Orbiter IV it appears that faint rille segments probably connect the Sheepshanks rilles to the Gärtner Rille to the east. I was going to say that testing this speculation will be possible with further release of LRO WAC images to the east, but I see that 16 year old Clementine data already confirm it! Hmm, what do we do with a rille whose two ends have different names?

Chuck Wood

Related Links
Rükl plate 5
The GLR group published a paper on this rille but I do not have a copy to see what they discovered: Raffaello Lena , KC Pau and Piergiovanni Salimbeni. 2004. Observations of the Rima Sheepshanks. Selenology 23, 1.

Yesterday's LPOD: Basinal Surprises

Tomorrow's LPOD: Passing of a Friend



COMMENTS?

Register, Log in, and join in the comments.