Difference between revisions of "June 14, 2006"

From LPOD
Jump to: navigation, search
Line 15: Line 15:
 
<p><b>Yesterday's LPOD:</b> [[June 13, 2006|A Hot Day At Plato]] </p>
 
<p><b>Yesterday's LPOD:</b> [[June 13, 2006|A Hot Day At Plato]] </p>
 
<p><b>Tomorrow's LPOD:</b> [[June 18, 2006|Oozing Ejecta]] </p>
 
<p><b>Tomorrow's LPOD:</b> [[June 18, 2006|Oozing Ejecta]] </p>
<p align="center">
+
<!-- Removed reference to store page -->
<i>You can support LPOD when you buy ANY book from Amazon thru [http://www.lpod.org/?page_id=102  LPOD!]</i></p>
 
<p><b>Yesterday's LPOD:</b> [[June 13, 2006|A Hot Day At Plato]] </p>
 
<p><b>Tomorrow's LPOD:</b> [[June 18, 2006|Oozing Ejecta]] </p>
 
 
</div>
 
</div>
 
----
 
----

Revision as of 15:54, 1 February 2015

Primaries or Secondaries?

AS10-29-4324.jpg
image by Apollo 10 fromApollo Image Gallery

Moltke crater is probably best known as a guidepost to the Apollo 11 landing site. It is a fresh, 7 km wide simple crater with steep bowl-shaped walls. This Apollo 10 image beautifully shows the ejecta deposits that surround it. On a higher Sun view the ejecta shows up as a bright patch; in this closeup it is seen as a thinning pile of bumpy hills (called hummocks by geologists) and beyond them tiny secondary impact craters. In fact, this area - like every area seen at extreme high resolution - is peppered with tiny craters. Some are clearly secondaries (the wormy chains in the foreground) and any none clump member crater is assumed to be a primary impact. But a study of a very young impact crater on Mars has led some researchers to believe that millions of secondary craters may be created by the formation of a moderate size primary crater. That would mean that most small (with diameters less than 2 km) craters on Mars and the Moon are secondaries. And thus estimates of surface ages based on counts of small craters would be unreliable. Most craters observed telescopically are larger than 2 km and are probably primaries, but when looking at a great space image like this it is possible that nearly all of the small craters are secondaries.

Chuck Wood

Technical Details:
AS10-29-4324
NOTE: I will be at a games + society meeting in Madison, Wisconsin the next few days - look for a new LPOD on Sunday.

Related Links:
Rükl plate 46

Yesterday's LPOD: A Hot Day At Plato

Tomorrow's LPOD: Oozing Ejecta


COMMENTS?

Register, and click on the Discussion tab at the top of the page.


Contributions to http://www2.lpod.org/ are licensed under a Creative Commons Attribution No-Derivative-Works Non-Commercial 3.0 License. by-nc-nd_3.0_80x15.png