Mercury Flyby 1 Options

[Stu]

Being totally honest here, I don't know why I find this crater - visible on one of the new images - so fascinating, I just do...



Maybe it's the smaller crater in the middle... lots of detail around it, and with its irregular rim it looks to my woefully untrained eye like either a few small objects hit there, or there's been some slumping after the craterlet was formed...

Just fascinating!

[scalbers]

Greetings,

I've now incorporated the Messenger wide-angle outbound image in the Mercury map. On my website this has also been increased in size to a 4K image. Here is a link:

http://laps.noaa.gov/albers/sos/sos.html#MERCURY



Note that in this fairly close in Messenger view the perspective with such a wide angle camera ends up with the poles being significantly beyond the horizon.

Steve

[Stu]

Looking at these images has made me ask again just why I find them so fascinating, and yet again I haven't been able to put it into words. But, in a wonderful coincidence, I took a book out of the library the other day which kind of did it for me. The book is "READING THE ROCKS" by Marcia Bjornerud, and, well, it's just a fantastic, passionate, personal window into the science of geology. This is just from the prologue...

"Like the place names on the highway map, which are a palimpest record of human interaction with the land, rocks and landscapes are Earth's unsystematic chronicle of its past - its unintentional autobiography. Autobiographies are unavoidably subjective accounts of past events, blurred by imperfect memory, limited by myopia, and edited for aesthetic, egotistical or legal reasons. To write an autobiography requires consciousness of self, and this by definition precludes the possibility of creating an objective and comprehensive chronicle. The one autobiography that has been recorded with no self-consciousness is Earth's own life story, written, very literally, in stone.

"Unfortunately, stone has an undeserved reputation for being uncommunicative. The expressions stone deaf, stone cold, stony silence, and, simply, stoned, reveal much about the relationship most people have to the rocks beneath their feet. But to a geologist, stones are richly illustrated texts, telling gothic tales of scorching heat, violent tempests, endurance, cataclysm and reincarnation. Over more than 4 billion years, in beach sand, volcanic ash, granites and garnet schists, the planet has unintentionally kept a rich and idiosynchratic journal of its past."

Looks like Mercury has, too...

[Phil Stooke]

Here's a rough reprojection of today's limb view. This area was on the outbound limb for Mariner 10, but seen much better here.

Phil

[elakdawalla]

Really cool, Phil. This makes it obvious that the area in the center of the image identified as "smooth plains" in the image caption is the very very flat floor of an ancient, infilled double-ring crater. Only about a third of its inner ring remains, but you can clearly see the circular expression of the outer ring.

--Emily

[Juramike]

I don't know about that. The linear features in that crater are most likely either lava flow fronts or tectonic ridges. If lava flow fronts, it's just an area where the lava didn't go.

Possibly. The key is the relative lack of craters in the "interior" part of the putative collapse zone and the sharp contrast between the cute crater cluster and no craters. Something either obscured part of the crater clusters or messed it up.

From the shading it appears that the center part of the zone is in a relative depression. So one possibility is that there were two (lava or debris) flow fronts to initially form the relative depression, then a third flow came down between them (and was overall lower) to infill the depression, which then partially covered up the cute crater cluster at the terminus. There is a dark line in the middle of the section, possibly indicating that the southern (in the image) part of this area is lower than the area near the terminus. Hard to explain how a debris flow would go uphill.

Or the whole section dropped and formed a graben, and any craters of the cute crater cluster that were on the dropped side of the graben got jumbled up and smoothed over during the reshuffling. Maybe this is one terminus of a rille?


-Mike

[JRehling]

[...]

[Phil Stooke]

That's my view too.

Phil

[Stu]

Don't you just love those craters with a central peak that took a direct hit later?

To quote the great Harry Hill, "What are the chances of that happening, eh?"

[Juramike]

And thus, it would not be the case that something interrupted the cluster, but that it never extended into the smoother area.

Ahhh, very interesting! So perhaps several of the crater clusters were formed by just having unobscured ballistic vectors from different impacts. A low cliff over there, another low cliff over there, and voila, an apparent concentration of craters from two seperate impacts.

I guess conversely, there might be a few relatively (secondary) crater-free areas where secondary impacts never hit just because of the lucky placement of objects that blocked flung debris.

Thanks!

-Mike

[JRehling]

[...]

[MarsIsImportant]

First of all, I didn't say that that crater was a caldera. I simply stated we need a much closer look at it. We need to gather all the facts on the ground. I merely suggested that it appears it could be one, not that it is one.

I am extremely aware of what both impact craters and calderas look like. I stand by my previous statement 100%. I was correct about the glacial features on Mars too. Nobody believed me about that either until recently when much of my suspicions were substantiated. This time I'm not stating anything as fact. We should keep an open mind, until we analyze all the data. I know that a variety of processes can make some of these features. Let's gather all the facts we can before we make a final determination.

[marswiggle]

A completely unprofessional attempt for our (and my) first Mercury anaglyph, using the two partly overlapping releases, showing the crater intersected by a fault near the equator by the day-night border. Some problems regarding the geometry, but I simply resized and aligned the images suitably so that it feels nice to look at. It appears to show some topography. Enjoy.

Attached thumbnail(s)

 

[Astro0]

Great images coming down.
Here's a context image that someone clever on UMSF might want to build upon.


Astro0

PS: I have larger version but it's 9.4mb. I might post it somewhere later.

[Astro0]

A fanciful view of the flyby for your desktop.


Enjoy
Astro0