[meteorite-list] Two New Images from MESSENGER's First FlybyofMercury

From: Jerry <grf2_at_meteoritecentral.com>
Date: Wed, 16 Jan 2008 23:45:47 -0500
Message-ID: <598064BBF91E4A94A7F11D944EED9CDE_at_Notebook>

collapse lava tubes as opposed to impact chains [oh darn]
Jerry Flaherty
----- Original Message -----
From: "Sterling K. Webb" <sterling_k_webb at sbcglobal.net>
To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>
Cc: "Gerald Flaherty" <grf2 at verizon.net>; "Ron Baalke"
<baalke at zagami.jpl.nasa.gov>; "Larry Lebofsky" <lebofsky at lpl.arizona.edu>
Sent: Wednesday, January 16, 2008 10:24 PM
Subject: Re: [meteorite-list] Two New Images from MESSENGER's First
FlybyofMercury


> Hi, Jerry,
>
> That is the received wisdom derived from study of
> our Moon, that bright rayed craters are fresher. I would
> think that it would be truer on Mercury than the Moon,
> as the UV intensity and the strength of the solar wind
> should darken them faster. You could probably get a
> great tan and a light microwaving in no time on Mercury.
>
> There are a multitude of teeny craters like freckles
> and lots of very crisp small craters, while most of
> the medium and large craters do not look fresh. In the
> very first closeup picture released, there was a good sized
> crater with a brighter fresher crater 60% of its size almost
> dead center inside of it!
>
> How many impacts that size do you have to have to
> get two shots on dead center? Lots. I've been flipping
> through pictures of other surfaces to see if I can find
> another example like that and, so far, I can't. The crater-
> counters will have a field day!
>
> It's also surprising how many linear crater alignments
> there are. There will be a repeat of the arguments from
> lunar days of whether they are Shoemaker-Levy-style
> multi-impact chains or collapsed lava tubes.
>
> Mercury only looks like the Moon at a casual glance.
> Even in the old Videcon TV pictures of Mariner 10,
> it looked strange. In these closer, much more detailed
> images, it looks even stranger. Lots of collapse features.
> There may be more vulcanism than we think likely.
>
> Ah! There's a good argument!
>
>
> Sterling K. Webb
> --------------------------------------------------------------------------------
> ----- Original Message -----
> From: "Jerry" <grf2 at verizon.net>
> To: "Ron Baalke" <baalke at zagami.jpl.nasa.gov>; "Meteorite Mailing List"
> <meteorite-list at meteoritecentral.com>
> Sent: Wednesday, January 16, 2008 8:55 PM
> Subject: Re: [meteorite-list] Two New Images from MESSENGER's First
> Flybyof
> Mercury
>
>
> Do the bright rays indicate a more "recent" impact?
> Jerry Flaherty
> ----- Original Message -----
> From: "Ron Baalke" <baalke at zagami.jpl.nasa.gov>
> To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>
> Sent: Wednesday, January 16, 2008 8:36 PM
> Subject: [meteorite-list] Two New Images from MESSENGER's First Flyby of
> Mercury
>
>
>>
>> http://messenger.jhuapl.edu/news_room/status_report_01_16_08_2.html
>>
>> MESSENGER Mission News
>> January 16, 2008 [Evening Update]
>>
>> Two New Images from MESSENGER's First Flyby of Mercury
>>
>> Detailed Close-up of Mercury's Previously Unseen Surface
>>
>> Just 21 minutes after MESSENGER's closest approach to Mercury on January
>> 14, 2008, the Narrow Angle Camera (NAC) took this picture
>> <http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=119>
>> showing a variety of intriguing surface features, including craters as
>> small as about 300 meters (about 300 yards) across.
>>
>> This is one of a set of 68 NAC images showing landscapes near Mercury's
>> equator on the side of the planet never before imaged by spacecraft.
>>>From such highly detailed close-ups, planetary geologists can study the
>> processes that have shaped Mercury's surface over the past 4 billion
>> years.
>>
>> One of the highest and longest scarps (cliffs) yet seen on Mercury
>> curves from the top center down across the right side of this image.
>> (The Sun is shining low from the left, so the scarp casts a wide
>> shadow.) Great forces in Mercury's crust have thrust the terrain
>> occupying the left two-thirds of the picture up and over the terrain to
>> the right. An impact crater has subsequently destroyed a small part of
>> the scarp near the top of the image.
>>
>> This image was taken from a distance of only 5,800 kilometers (3,600
>> miles) from surface of the planet and shows a region about 170
>> kilometers (about 100 miles) across.
>>
>> Mercury's Cratered Surface
>>
>> During its flyby of Mercury, the MESSENGER spacecraft acquired
>> high-resolution images of the planet's surface. This image
>> <http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=120>,
>> taken by the Narrow Angle Camera (NAC) on the Mercury Dual Imaging
>> System (MDIS), was obtained on January 14, 2008, about 37 minutes after
>> MESSENGER's closest approach to the planet. The image reveals the
>> surface of Mercury at a resolution of about 360 meters/pixel (about
>> 1,180 feet/pixel), and the width of the image is about 370 kilometers
>> (about 230 miles).
>>
>> This image is the 98th in a set of 99 images that were taken in a
>> pattern of 9 rows and 11 columns to enable the creation of a large,
>> high-resolution mosaic of the northeast quarter of the region not seen
>> by Mariner 10. During the encounter with Mercury, the MDIS acquired
>> image sets for seven large mosaics with the NAC.
>>
>> This image shows a previously unseen crater with distinctive bright rays
>> of ejected material extending radially outward from the crater's center.
>> A chain of craters nearby is also visible. Studying impact craters
>> provides insight into the history and composition of Mercury as well as
>> dynamical processes that occurred throughout our Solar System. The
>> MESSENGER Science Team has begun analyzing these high-resolution images
>> to unravel these fundamental questions.
>>
>> ------------------------------------------------------------------------
>>
>> MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and
>> Ranging) is a NASA-sponsored scientific investigation of the planet
>> Mercury and the first space mission designed to orbit the planet closest
>> to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and
>> after flybys of Earth, Venus, and Mercury will start a yearlong study of
>> its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie
>> Institution of Washington, leads the mission as principal investigator.
>> The Johns Hopkins University Applied Physics Laboratory built and
>> operates the MESSENGER spacecraft and manages this Discovery -class
>> mission for NASA.
>>
>>
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Received on Wed 16 Jan 2008 11:45:47 PM PST