Difference between revisions of "July 2, 2019"

From LPOD
Jump to: navigation, search
(Created page with "__NOTOC__ =Another Ina?= Originally published March 20, 2010 <!-- Start of content --> <!-- ws:start:WikiTextHeadingRule:1:<h1> --> <!-- ws:start:WikiTextLocalImage...")
 
(No difference)

Latest revision as of 01:05, 2 July 2019

Another Ina?

Originally published March 20, 2010 LPOD-Mar20-10.jpg
LROC Observation M104476560L from LROC WMS Image Map (illumination from the left)

The peculiar depression Ina has a bizarre floor of rubbly hills and islands of smooth terrain. Sorting through the LRO images released on March 15 I found this image of part of the floor of Hyginus crater that looks similar. The largest roughly circular feature is 350-400 m wide, but it is not clear what the feature is. Smaller circular to irregular depressions are across the scene. The arcuate depression on the left looks like it continues as a circular feature covered by the darker material. But if Hyginus is like Ina, the dark smooth material is as old as maria outside Hyginus, suggesting that it is not a younger deposit. Thus, it seems that something is removing the terrain under the original mare surface. Like Ina, Hyginus is thought to be a volcanic collapse depression. Perhaps volcanic gases dissolve the regolith in volcanic craters causing this characteristic pattern. But what gas would do this? Comparison with the 43 year old Orbiter V image reveals no obvious changes so the process does not appear to be active on a human timescale.

Chuck Wood

Related Links
Rükl plate 34
Note that Pete Schultz and colleagues included Hyginus as an Ina-like object in their 2006 paper.

Yesterday's LPOD: The Case of the Missing Rim

Tomorrow's LPOD: How Thick Are Rays?



COMMENTS?

Register, Log in, and join in the comments.