IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
Mercury's Hidden Side Observed
nprev
post Mar 28 2007, 02:16 AM
Post #1


Senior Member
****

Group: Moderator
Posts: 7086
Joined: 8-December 05
From: Los Angeles
Member No.: 602



An ambitious astronomer takes advantage of a rare opportunity to photograph the hemisphere of Mercury we almost never get to see via telepresence in Chile. Article 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.
Go to the top of the page
 
+Quote Post
stevesliva
post Mar 28 2007, 04:01 AM
Post #2


Senior Member
****

Group: Members
Posts: 1168
Joined: 14-October 05
From: Seattle
Member No.: 530



I believe the best images I have heard of are radar images from Arecibo. It would be interesting to compare to visual or IR.

edit: ah, of course, from this very forum. wink.gif
Go to the top of the page
 
+Quote Post
JRehling
post Mar 28 2007, 11:47 PM
Post #3


Senior Member
****

Group: Members
Posts: 1572
Joined: 20-April 05
Member No.: 321



QUOTE (nprev @ Mar 27 2007, 07:16 PM) *
An ambitious astronomer takes advantage of a rare opportunity to photograph the hemisphere of Mercury we almost never get to see via telepresence in Chile. Article here.


No picture?!

Given the time the work was done, the image should include the 25% or so of Mercury that is just west of the Mariner hemisphere -- that will include pretty much the entire Caloris Basin. The exciting thing there is the possibility of relief visible at the rim.

Let's see the image!
Go to the top of the page
 
+Quote Post
nprev
post Mar 29 2007, 03:42 AM
Post #4


Senior Member
****

Group: Moderator
Posts: 7086
Joined: 8-December 05
From: Los Angeles
Member No.: 602



Can't find any pics yet...assuming that he's working on publishing his results. Don't expect much, though; pretty much every ground-based optical image of Mercury I've seen looks like a bad pic of Mars with nothing evident but gross albedo features.

However, he did acquire something like 300,000 images, so maybe image stacking & other techniques will bring out some good stuff. Lots of data-crunching needed, though.

Hell, here's a wild thought: does he need some help? Some of the incredibly talented imagesmiths among us might be able to simplify the process considerably; why not contact him & ask? He's a state university prof, can't imagine that he has an abundance of resources...


--------------------
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.
Go to the top of the page
 
+Quote Post
J.J.
post Mar 29 2007, 03:47 AM
Post #5


Junior Member
**

Group: Members
Posts: 84
Joined: 22-March 06
Member No.: 722



^
Or another way, the best the pictures of Mercury today look like the best film pictures of Mars 30 years ago. wink.gif


--------------------
Mayor: Er, Master Betty, what is the Evil Council's plan?

Master Betty: Nyah. Haha. It is EVIL, it is so EVIL. It is a bad, bad plan, which will hurt many... people... who are good. I think it's great that it's so bad.

-Kung Pow: Enter the Fist
Go to the top of the page
 
+Quote Post
Rob Pinnegar
post Mar 29 2007, 12:29 PM
Post #6


Member
***

Group: Members
Posts: 501
Joined: 2-July 05
From: Calgary, Alberta
Member No.: 426



QUOTE (nprev @ Mar 28 2007, 09:42 PM) *
Hell, here's a wild thought: does he need some help? Some of the incredibly talented imagesmiths among us might be able to simplify the process considerably; why not contact him & ask? He's a state university prof, can't imagine that he has an abundance of resources...

That's a nice sentiment -- but if he's working on publishing it, which seems very likely, I think he'd probably be nervous about turning the data over to a bunch of Internet people.

Also, in a publication, he would have to be able to describe in detail all of the data processing steps -- which generally would mean no use of "black box" commercial processing software. (There are people out there who write their own processing code in Fortran or C because they don't even trust Matlab -- and although I *do* trust Matlab, I can understand this.)
Go to the top of the page
 
+Quote Post
nprev
post Mar 30 2007, 01:37 AM
Post #7


Senior Member
****

Group: Moderator
Posts: 7086
Joined: 8-December 05
From: Los Angeles
Member No.: 602



Ah; the perils of academia. Yeah, Rob, that sounds about right.

Pity, though. The Internet provides an opportunity for a whole new level of pro-am collaboration above & beyond what astronomy has enjoyed for decades with respect to comet, asteroid and nova/supernova discoveries as well as planetary observation & variable star monitoring. Few if any other scientific disciplines have such a connection with the general public, and it has proven quite profitable. There is an extremely lucrative resource for data processing just waiting to be tapped by the pros with the enthusiastic participation of amateurs...some smart cookie somewhere's gonna figure this out! wink.gif


--------------------
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.
Go to the top of the page
 
+Quote Post
PhilHorzempa
post Mar 31 2007, 04:33 PM
Post #8


Member
***

Group: Members
Posts: 164
Joined: 17-March 06
Member No.: 709



This might be a good thread to post images of the "Far Side" of Mercury,
the side not imaged by Mariner 10. The bulk of the high-res images are
probably the Radar ones. However, the visible Earth-based telescopic views
of the Far Side would be nice to see. Then we can wait only a few more months
and see what Messenger reveals about that Far Side.
To start, could anyone in UMSF post those detailed Radar images? I have
seen one of a large crater (with ejecta blanket?) - does anyone have access
to a digital version of that?

Another Phil
Go to the top of the page
 
+Quote Post
angel1801
post Mar 31 2007, 05:47 PM
Post #9


Member
***

Group: Members
Posts: 150
Joined: 4-March 06
Member No.: 694



I have checked my harddisk and I do have an radar image on Mercury centred at 35S 345W which looks just like the image you're wanting.

Is this it?



--------------------
I call heaven and earth to witness against you this day, that I have set before thee life and death, the blessing and the curse; therefore choose life, that thou mayest live, thou and thy seed.

- Opening line from episode 13 of "Cosmos"
Go to the top of the page
 
+Quote Post
tedstryk
post Mar 31 2007, 06:12 PM
Post #10


Interplanetary Dumpster Diver
****

Group: Moderator
Posts: 4241
Joined: 17-February 04
From: Powell, TN
Member No.: 33



There is a lot of good stuff in this thread.


--------------------
Go to the top of the page
 
+Quote Post
nprev
post Apr 2 2007, 02:43 PM
Post #11


Senior Member
****

Group: Moderator
Posts: 7086
Joined: 8-December 05
From: Los Angeles
Member No.: 602



Thanks, Ted; good stuff indeed! smile.gif

Kind of interesting that there don't seem to be any volcanic constructs on Mercury at all; even the Moon seems to have more of that sort of thing. I know Mercury's crust is thought to be inordinately thick, but it also has a huge core & a magnetic field, so you'd think there'd be a bit more surface activity evident. Maybe we'll see some small domes around Caloris from Messenger.


--------------------
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.
Go to the top of the page
 
+Quote Post
J.J.
post Apr 3 2007, 03:47 PM
Post #12


Junior Member
**

Group: Members
Posts: 84
Joined: 22-March 06
Member No.: 722



^
Mercury's "intercrater plains" are often cited as analogues of lunar maria, but to me they appear much more subtle.


--------------------
Mayor: Er, Master Betty, what is the Evil Council's plan?

Master Betty: Nyah. Haha. It is EVIL, it is so EVIL. It is a bad, bad plan, which will hurt many... people... who are good. I think it's great that it's so bad.

-Kung Pow: Enter the Fist
Go to the top of the page
 
+Quote Post
dvandorn
post Apr 3 2007, 04:53 PM
Post #13


Senior Member
****

Group: Members
Posts: 3238
Joined: 9-February 04
From: Minneapolis, MN, USA
Member No.: 15



The most common theory I've heard in re Mercury is that it encountered one or more "big whack"-sized impacts, but that being so close to the Sun and being intrinsically less massive than Earth or Venus, a majority of the ejected material (including most of Mercury's original crust and mantle) never re-accreted onto the planet.

With only a small percentage left of its original silicate mantle, I can imagine that volcanic processes on Mercury would have resulted in landforms that don't look distinctively volcanic -- especially when compared to bodies such as Earth, Luna or Mars.

For example, let's say that only the densest portion of Mercury's mantle was retained. This, and the crystallization of the outer layers of the remnant mantle to form a new crust, could leave only highly viscous, iron-rich lavas available for subsequent extrusion. And since the new crust formed late in the accretion process, you don't see big pile-ups of lava -- as it extruded onto the already thin crust, the whole thing flattened out and the flow features were made very subtle. Thus the distinctive, low-and-rolling landforms of the intercrater plains.

-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
JRehling
post Apr 3 2007, 05:16 PM
Post #14


Senior Member
****

Group: Members
Posts: 1572
Joined: 20-April 05
Member No.: 321



My own post-digested view of the literature on Mercury is best expressed in terms of contrast with the Moon.

The Moon, about a quarter the mass of Mercury, lost its interior heat more quickly, and by 4.2-4.0 GYA, was a mainly solid world with just a bit of volcanic heat left to lose (roughly like Earth and Venus today). Most of its crust was hardened as far as endogenous factors went, so it was shaped primarily by the saturation bombing of impacts. When the bombardment ended, the highlands ended up in their terminal state -- utterly rugged chaos of craters on craters. Meanwhile, the lowlands which began that way were paved smooth by the last vestiges of lunar volcanism.

On Mercury, with a larger world radiating its heat more slowly (not to mention the fact that one side is baked by the Sun and the larger crust probably had more radiogenetic heat), the crust was still more malleable as the bombardment from impacts died out. Neither process ended abruptly in a few hours, but the two gradually died down at the same time, leaving a crust with smooth areas that melted flat after their last impact. Meanwhile, the contraction of the huge core led to some interesting topographic features so that the smooth areas are not glassy smooth like a frozen sea. Of course, some impacts still continued to strike, leaving the Mercurian highlands much more cratered than the lunar maria, but not nearly so completely as the lunar highlands. Finally, Mercury's volcanic heat also created a few smooth maria there.
Go to the top of the page
 
+Quote Post

Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 22nd October 2014 - 11:56 PM
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 a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.