InSight Surface Operations, 26 Nov 2018- 21 Dec 2022 |
InSight Surface Operations, 26 Nov 2018- 21 Dec 2022 |
Nov 26 2018, 08:20 PM
Post
#801
|
|
Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Congratulations to the InSight team on a successful landing! We'll discuss the remainder of the mission here.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
|
|
|
Jan 30 2020, 12:02 AM
Post
#802
|
||||
Member Group: Members Posts: 866 Joined: 15-March 05 From: Santa Cruz, CA Member No.: 196 |
Here is one set of the sol417 stereo pairs, from the left in crosseye/anaglyph/parallel renderings:
"the alien instrument descended as dusts of ages fell away revealing a sort of portal, as if a long buried Cenote emerging from the deep to accept the sacrifice" |
|||
|
||||
Jan 30 2020, 07:08 PM
Post
#803
|
|
Member Group: Members Posts: 684 Joined: 24-July 15 Member No.: 7619 |
Here is one set of the parallel renderings: Oh WOW. That is a HUGE amount of missing volume! Can that ALL be from compaction? I'm starting to think there is a void UNDER the duricrust, and the mole punched a small hole through which is allowing the soil to drop down into a void? |
|
|
Jan 30 2020, 08:46 PM
Post
#804
|
|
Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
Can that ALL be from compaction? It was partly wondering about this that prompted me to ask the question about densities a few posts back. Apart from the visible void there is the volume now occupied by the probe itself. If the regolith here is indeed very porous and lightly packed that would initially have helped the mole to sink. Maybe the hammering causes the stuff to collapse and there is now a much denser sand 'puddle' at the bottom of the hole. |
|
|
Jan 31 2020, 11:13 AM
Post
#805
|
|
Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
The presence of duricrust implies the previous presence of saline water from which the water departed. To some extent, this compaction must be showing us how much water there once was.
|
|
|
Feb 2 2020, 10:51 AM
Post
#806
|
|
Senior Member Group: Members Posts: 1057 Joined: 17-February 09 Member No.: 4605 |
The presence of duricrust implies the previous presence of saline water from which the water departed. To some extent, this compaction must be showing us how much water there once was. The scenario seems to be that the mole encountered a duricrust layer beneath the reasonably loose regolith. When the mole encountered the cemented layer there was insufficient friction against the barrel from the surface deposits to let it penetrate and the mole effectively bounced around compacting the (comparatively) loose material. The friction applied by the scoop permitted the mole to begin to penetrate the duricrust but the effect diminished with depth and the mole bounced back, possibly with loose material sifting down to progressively refill the hole. There is no way to tell how deep the duricrust layer is but it could be measured in metres, representing the surface a long time ago. |
|
|
Feb 3 2020, 05:34 AM
Post
#807
|
|
Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
The scenario seems to be that the mole encountered a duricrust layer beneath the reasonably loose regolith. Correct me if I'm reading this wrong, but that seems to me to be the opposite (vertically speaking) of what the team blog said on December 23: "The most convincing (at least to me) explanation for the backing out of the mole assumes that the duricrust is underlain by cohesionless sand." And further, "…motion of the mole provides an estimate for the thickness of the duricrust of about 20cm." You speak of a duricrust layer under loose regolith, but they speak of loose (cohesionless) material below the duricrust. And you speak of unknown thickness perhaps meters and they speak of about 20 cm. Perhaps they are wrong (they express uncertainty) but it seems like you are knowingly or unknowingly contradicting them. Again, my understanding from this is that there is a duricrust on the top, and that it has a definite end within cm from the surface. Viking found this to be just a couple of cm, but here the team supposes about 20cm. Then, there is a loose layer of unknown depth below that in this locality. Do you think the team is wrong or are we interpreting the wording differently? (I'm sure there is some degree of surface dust above the duricrust, but I was interpreting that as negligible, approximately or less than 1cm.) https://www.dlr.de/blogs/en/all-blog-posts/...on-logbook.aspx |
|
|
Lo-Fi Version | Time is now: 26th September 2024 - 06:57 AM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |