[X] My Assistant

[Tesheiner]

Well I think that Spirit has finally left Silica Valley for good --please don't tell me that we should go back again to Silica Valley because of another turned up soil deposit or cracked rock-- and is about to start another science campaign at Home Plate, so it would be time to start a new thread devoted to this period of time.

I said on a previous post on the older thread that it looks like the plan is to traverse the top. Digging on an old MER report (at TPS) I found this reference:

"The general desire is to stay on top of Home Plate, but follow the outcrop exposures around to the portion that everybody really wants to get to -- the far end or southwestern portion of Home Plate," said Yen.

Edited: This even older report might apply too.

At that time, the team will have to decide if Spirit will cross the diameter of Home Plate, roving radially toward the center and across the feature to look at what might be exposed. "If this feature is bowl-shaped, as the rover goes to the center, it will go higher and higher stratigraphically even though it's not going up in elevation," explained Banerdt. "That's one of the primary arguments for spending some time on top of Home Plate." There's no clear evidence of this stratification from MRO's HiRISE images. "But it could be there and just covered by surface dust," he suggested.

[dvandorn]

That's why I have such a hard time understanding the gut reaction a handful of planetary scientists seem to have at this apparent fact. Their reaction, instead of trying to constrain the time frames, the extent of standing water, the processes by which that water has been buried or trapped at the poles or sputtered way into the void, etc., etc., seems to be: "Well, wait -- there *must* be another explanation for this. There simply must. Let's see how many improbable theories we can generate to explain this, since it simply *cannot* be liquid water which made these landforms. Utterly impossible."

Every theory I hear, from "White Mars" to "insignificant capillary action and frosts", tries to explain away one tiny fragment of a growing body of overwhelming evidence, first and foremost of which is the morphological evidence. Yes, capillary action involving tiny amounts of water could have produced some of the alteration we've seen in rocks at Gusev -- but it doesn't explain the massive outflow channels. Yes, dry ice phase change physics can explain some aspects of some erosional features -- but it does not explain the meandering river valleys. And so on, and so on. The whole approach begs Occam's Razor to cease to exist -- it's like they want to abandon the obvious, simplest, most probable answer in favor of *anything* else.

It's like standing in the middle of the American southwest, pulling up abundant marine fossils from the ground, and spending the rest of your life feverishly trying to convince everyone that they must have somehow been transported there from some currently existing ocean. That the American southwest could *never* have been a seafloor, for the simple reason that it isn't one now.

Mars may have been like it is now, more or less, for a long time. But it was, for some period of time, a lot different. It's time to accept that and not feverishly argue that it couldn't have been...

-the other Doug