Scivillage.com Casual Discussion Science Forum

https://www.universetoday.com/138393/icy...soft-land/

EXCERPT: . . . What they found was that the bright grains that make up the surfaces of Europa and Enceladus would measure about a fraction of a micron and have a void space of about 95%. This corresponds to material that is less dense than freshly-fallen snow, which would seem to indicate that these moon’s have very soft surfaces. Naturally, this does not bode well for any missions that would attempt to set down on Europa or Enceladus’ surface. But as Nelson explained in PSI press release, this is not necessarily bad news, and such fears have been raised before...

MORE: https://www.universetoday.com/138393/icy...soft-land/

- - -

If the surface is consistent with that of a very fine powder then would it not behave like a liquid if disturbed? IOW, shouldn't we be able to observe waves emanating from geyser locations, traversing the surface? Meteor strikes & subsurface ice movement would do the same, filling in cracks & fissures with these powdery ice particles as well as erasing evidence of craters from the landscape, no?

(Feb 5, 2018 05:33 AM)Zinjanthropos Wrote: [ -> ]If the surface is consistent with that of a very fine powder then would it not behave like a liquid if disturbed? IOW, shouldn't we be able to observe waves emanating from geyser locations, traversing the surface? Meteor strikes & subsurface ice movement would do the same, filling in cracks & fissures with these powdery ice particles as well as erasing evidence of craters from the landscape, no?

Other atmosphere-less bodies are coated with regolith as well, but often like on the Moon it's composed of "mineral-ish" grains rather than ice particles. Europa has many streaks that are brown from irradiated salt (i.e., the bright porous stuff apparently hasn't filled / covered those). Researchers have also had a difficult time finding and completely confirming geyser plume candidates on Europa via surface signs (one is augmented by a detected heat-signature area rather than any visible geological pattern). So it may only be a very shallow accumulation there with solid terrain underneath. If enough were ever deposited for such, an absence of weather / climate and the source of "particle fall" possibly being from weak eruptions (and meteoroid strikes) wouldn't seem to prevent any settled layers from compressing into firmer strata.

- - -