IPB

Welcome Guest ( Log In | Register )

11 Pages V  « < 2 3 4 5 6 > »   
Reply to this topicStart new topic
Mercury Flyby 2
Marz
post Oct 5 2008, 05:03 PM
Post #46


Member
***

Group: Members
Posts: 311
Joined: 31-August 05
From: Florida & Texas, USA
Member No.: 482



Attached Image


Hoping someone can clue me in on what we're seeing:

Why is the crater pointed to with the green line so bright? Solar glare or is it surface composition?

Is the feature pointed to with the red line perhaps volcanic?



Go to the top of the page
 
+Quote Post
Juramike
post Oct 5 2008, 05:56 PM
Post #47


Senior Member
****

Group: Moderator
Posts: 2785
Joined: 10-November 06
From: Pasadena, CA
Member No.: 1345



The shading on the southern basin towards the terminator looks "not right" (shouldn't it be bright rather than shaded?). Or is that a processing artifact?

-Mike


--------------------
Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
Go to the top of the page
 
+Quote Post
remcook
post Oct 5 2008, 06:01 PM
Post #48


Rover Driver
****

Group: Members
Posts: 1015
Joined: 4-March 04
Member No.: 47



i agree. it looks more like the edge of olympus mons like this.
all the other craters seem to have the shadow on the 'right' side.
Go to the top of the page
 
+Quote Post
dvandorn
post Oct 5 2008, 06:41 PM
Post #49


Senior Member
****

Group: Members
Posts: 3419
Joined: 9-February 04
From: Minneapolis, MN, USA
Member No.: 15



Hmmm... no Skinakas? I see arc-shaped lobes of dark material, in some areas bounded by what appear to be old, degraded arcs of rimwall massif. I'm not a consummate image manipulator, but look within the crudely drawn red circle below:

Attached Image


I really do see a structure there that seems to be roughly concentric with that very roughly drawn red circle. Very degraded, yes -- the southern rim seems to have been obliterated by subsequent large craters. But this might be a basin, after all...

-the other Doug


--------------------
“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
Go to the top of the page
 
+Quote Post
volcanopele
post Oct 5 2008, 06:43 PM
Post #50


Senior Member
****

Group: Moderator
Posts: 3225
Joined: 11-February 04
From: Tucson, AZ
Member No.: 23



Looks like a good sized impact basin to me. Though it seems to be a central pit basin, rather than a central peak basin blink.gif

Doug, that looks like an optical illusion to me. I saw what you were talking about earlier, but now I really just see a chance alignment of craters.


--------------------
&@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io
Go to the top of the page
 
+Quote Post
Phil Stooke
post Oct 5 2008, 06:50 PM
Post #51


Solar System Cartographer
****

Group: Members
Posts: 10122
Joined: 5-April 05
From: Canada
Member No.: 227



The odd shading in the southern basin is most easily explained as one of those big lobate scarps crossing the floor, or possibly part of a multi-ring structure. That bright spot alluded to earlier - a fresh impact crater or one of those craters we saw in the first encounter with extremely bright deposits on the floor. The past (encounter 1) is the key to the present, at least to generate a first hypothesis.

As for 'skinakas' - the feature described from earth was a lot bigger than the darker spots outlined above. If there's a basin rim up there I can't see it.

Phil


--------------------
... because the Solar System ain't gonna map itself.

Also to be found posting similar content on https://mastodon.social/@PhilStooke
NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain)
Go to the top of the page
 
+Quote Post
dvandorn
post Oct 5 2008, 06:51 PM
Post #52


Senior Member
****

Group: Members
Posts: 3419
Joined: 9-February 04
From: Minneapolis, MN, USA
Member No.: 15



I almost decided it was a chance alignment of craters, too -- but my eye keeps going back to the dark-albedo arcs to the north and south. Those seem to be independent of the craters in the area, and their arc shapes define a big circular feature. Now, it seems to me that a big circular feature like that would have to be either the degraded remnants of a huge shield volcano or the degraded remnants of a basin. Since we've seen a lot of the latter and no other indications of the former, I sort of get led down the garden path to Skinakas...

-the other Doug


--------------------
“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
Go to the top of the page
 
+Quote Post
Fran Ontanaya
post Oct 5 2008, 07:24 PM
Post #53


Member
***

Group: Members
Posts: 293
Joined: 22-September 08
From: Spain
Member No.: 4350



It will be interesting to see if there are volcanoes at the opposite side of Caloris Basin. So far the southern side looks less cratered.

Go to the top of the page
 
+Quote Post
Holder of the Tw...
post Oct 5 2008, 08:14 PM
Post #54


Member
***

Group: Members
Posts: 540
Joined: 17-November 05
From: Oklahoma
Member No.: 557



QUOTE (dvandorn @ Oct 5 2008, 01:51 PM) *
I almost decided it was a chance alignment of craters, too -- but my eye keeps going back to the dark-albedo arcs to the north and south.


I know what you mean. I can't get over the feeling that there is something there. At the very least, we may be seeing the chance illusion that led to Skinakas in the first place. This may be one of those cases where more detail isn't going to help, and the coarse resolution pictures may show it best, provided there is an "it". If there is an old basin there, it may take laser altimetry from orbit to settle the issue.

Well, I may regret this, but I'm going to vote that there is something to Skinakas.
Go to the top of the page
 
+Quote Post
Rob Pinnegar
post Oct 6 2008, 12:04 AM
Post #55


Member
***

Group: Members
Posts: 509
Joined: 2-July 05
From: Calgary, Alberta
Member No.: 426



QUOTE (Holder of the Two Leashes @ Oct 5 2008, 02:14 PM) *
At the very least, we may be seeing the chance illusion that led to Skinakas in the first place.


This one had occurred to me as well. Maybe that's what we ought to concentrate on trying to sort out.

I wonder if the illusion (if that's what it is) could be reproduced by taking some of tomorrow's images, and running them through a low pass filter to fuzz them out a bit?
Go to the top of the page
 
+Quote Post
Phil Stooke
post Oct 6 2008, 12:22 AM
Post #56


Solar System Cartographer
****

Group: Members
Posts: 10122
Joined: 5-April 05
From: Canada
Member No.: 227



My opinion is that Skinakas is nothing more than a region relatively free of ray craters, appearing a bit darker than its surroundings. You have to look at the original paper to see how tenuous the basin interpretation was. That sort of study can be done with these early images, there's no need to wait.

Check it out here - figure 9 is the image.

http://www.alpo-astronomy.org/mercury/Ksanfomality.pdf

Phil


--------------------
... because the Solar System ain't gonna map itself.

Also to be found posting similar content on https://mastodon.social/@PhilStooke
NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain)
Go to the top of the page
 
+Quote Post
dmuller
post Oct 6 2008, 12:24 AM
Post #57


Member
***

Group: Members
Posts: 340
Joined: 11-April 08
From: Sydney, Australia
Member No.: 4093



Just over 8 hrs to closest approach, Messenger is now inside Mercury's hill-sphere. First wave of systems flyby mode activation is now just 2 hours away. Mercury is now "growing" noticeably as seen from Messenger ... JPL's solar system simulator seems to be holding up at present, so you can still watch the auto-refreshed images and timeline ticking by on my timeline simulator at http://www.dmuller.net/messenger


--------------------
Go to the top of the page
 
+Quote Post
Hungry4info
post Oct 6 2008, 12:49 AM
Post #58


Senior Member
****

Group: Members
Posts: 1413
Joined: 26-July 08
Member No.: 4270



A new picture appeared.
http://messenger.jhuapl.edu/gallery/scienc...0131695690M.jpg


--------------------
-- Hungry4info (Sirius_Alpha)
Go to the top of the page
 
+Quote Post
volcanopele
post Oct 6 2008, 12:59 AM
Post #59


Senior Member
****

Group: Moderator
Posts: 3225
Joined: 11-February 04
From: Tucson, AZ
Member No.: 23



Very nice. Now high enough res to actually do some analysis, not just make guess as to what we are seeing (even if it is a lot of fun wink.gif

The southern hemisphere basin looks like a double-ring basin with a dark-halo crater near the center of it. The very bright spot in the northern hemisphere looks like a small ray crater, but very fresh with a lot bright material surrounding it. I see no evidence to support a large, northern hemisphere basin


--------------------
&@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io
Go to the top of the page
 
+Quote Post
Juramike
post Oct 6 2008, 01:15 AM
Post #60


Senior Member
****

Group: Moderator
Posts: 2785
Joined: 10-November 06
From: Pasadena, CA
Member No.: 1345



Arrgh. VP beat me to it!

Anyway here's my contrast enhanced view of the southern multi-ring basin, and two other smaller multi-ring craters up at the top of the image. The bright reflection of the outer ring of the southern ring basin is visible (and bright like you'd expect).
Attached Image




(And I'm gonna assume that's a hot pixel or cosmic ray hit just off Mercury's limb)

-Mike

[EDIT: The edge of the southern basin at the terminator is gonna look really dramatic as we get closer!]


--------------------
Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
Go to the top of the page
 
+Quote Post

11 Pages V  « < 2 3 4 5 6 > » 
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 19th March 2024 - 04:59 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and 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.