Comments on: Friday at the non-existent Lunar & Planetary Science Conference

By: Lee S

Lee S — Mon, 23 Mar 2020 19:23:06 +0000

@Bob…. Every once in a while we are in total agreement!!!
I’m a little versed in geology, ( as I know you are!) and given Mars’s apparent lack of tectonic activity, there is no wonder we see so many different strata…. It’s been laid down over litteraly billions of years…. It’s just those bloody strata of ice that keep me awake at night! I just cannot wrap my head around any process that could leave such multiple, thick strata of ice in place, virtualy untouched, and relatively young, as they always seem to be high up in the bedding.
I hope that little drone attached to perceiverance works… What work could be done with an up close and personal look at that bedding!!!

By: Robert Zimmerman

Robert Zimmerman — Sat, 21 Mar 2020 20:36:07 +0000

In reply to Lee S. Lee S: I have not yet seen any theoretical models attempting to explain the layering. I suspect this is because we do not yet have enough data to put one together. We see layering and we see that some layers appear to be water ice, but this is about all we know. We do know know the extent globally of these ice tables underground (how close to the equator you might find them), we do not know their thickness or age, we do not know the thickness or age of all adjacent layers, and we do not know their extent. Essentially it is too soon to make any theories on the cause of the layering that has been seen. The focus now is on gathering data, most of which must be done very remotely, making any conclusions of what we see somewhat tentative also. For example, the many glaciers I write about are buried, and most have not been confirmed as water. They might not be, though the data suggests they are.

By: Lee S

Lee S — Sat, 21 Mar 2020 15:37:28 +0000

@ Max…. a decent theory… But I still don’t buy it…. It would have taken many catastrophic events to create this many levels of strata… Remember ice floats…. I can’t imagine any event which would vaporise all the liquid, without melting the surface ice, let that ice settle, have time to be covered in ejecta, etc…
Mercury could in theory be mined… Humans could no doubt live just over the border of night and day, and utilise the temperature gradient for almost unlimited power… But as you say… Getting out of the gravity well would be hard work!

By: Lee S

Lee S — Sat, 21 Mar 2020 15:28:34 +0000

Bob Z, while I might not read everything you write on politics, I certainly do on planetary geologist matters, and I’m aware of the theory that movements in the inclination of Mars would cause liquid/freezing cycles, I’m inclined to agree with you! ( Admit it… That was a half decent pun!), And glacier flow is obvious, indeed probably still occuring.
My curiosity is poked by where did the water come from?
These layers seem to be planet wide, and many meters deep…. do you have any theory how several layers of relativity pure water ice can be layered between relatively thick layers of rock? It’s a remarkably defined set of strata… So did the water on one side settle as ice, then did the water on the other side settle, then some event layed down the rock layer, then the water on the other side freeze… Oh, hang on… It’s already been frozen and covered in some form of ejecta.
I wish YOU would consider a pertinent question before refering to your previous posts…. As far as I know, nothing had been published on any REAL mechanism how these strata were laid down.

By: Max

Max — Sat, 21 Mar 2020 02:31:21 +0000

Excellent!
When it comes to mercury and mars, nothing is as simple as it appears. There’s always more questions than answers.
As Bob often notes, the northern hemisphere, which is relatively flat on Mars, is lower than southern rough hemisphere. Yes it could’ve been an ocean, most likely it is the largest impact crater in the solar system. The crust would be fractured miles deep.
A second impact craters, Helena’s basin, was so violent and deep that it pushed up tharsis bulge on the other side of the planet. Four of the resulting giant volcanoes pushed out enough lava to cover continents. And probably enough gas to create a thick warm atmosphere… If temporary. Oceans or ice would have melted and seeped into those deep crevices and regolith.
Ever since I saw the average air pressure on Mars near 7 millibars, I knew it wasn’t a coincidence. The threshold for water ice boiling into a gas.
When the atmosphere gets too thin, the water evaporates maintaining the air pressure until the water is all gone. This is evidence of water still existing under the surface.

As for Mercury, it is much too dense for its size. How could it have such a large iron core? I like the theory that it was once a gas giant that passed through the sun and lost its momentum and atmosphere. I know, a fantasy… Core samples would verify from normal, or exotic materials under the surface. I still believe it is the most habitable planet second only to the moon in resources and energy. At 1/2 an astronomical unit away, with a thick atmosphere “Venus” for aerobraking, it’s only a few months away as compared to the astroid belt at three astronomical units or Jupiter and its moons at five astronomical units. Whoever goes out there won’t be coming back (until they’re very old)

By: Robert Zimmerman

Robert Zimmerman — Fri, 20 Mar 2020 21:19:43 +0000

In reply to Lee S. Lee S: I wish you would read my posts about Mars more closely. I have addressed this question a number of times. The layering on Mars is almost certainly related to the swings in the planet's inclination. See all the posts in this BtB search. Or read this post, where I specifically discuss the subject: Buried glaciers flowing off of Martian mesa This cyclical process certainly could have caused the layering. Makes perfect sense.

By: Lee S

Lee S — Fri, 20 Mar 2020 21:02:04 +0000

I can see no obvious problems with your glacier theory, a build up of enough ice will slide downhill. But if I , (and you) are reading the photos from the last 15 earth years correctly, there are distinct geological layers, many, many years separating them, meters deep…A rock layer… Then an ice layer… Then a rock layer….
The water ice seems to be high up in the strata… Although ancient, not so much compared to the strata below… All good news for future colonists, but did/have you seen any theories how this could be possible?… It leaves me scratching my head…