Goodbye Victoria, The long trek has started Options

[Phil Stooke]

Shaka - check these out: (they lead to JPGs, resolution reduced but still OK)

Here's a giant example:

http://hirise-pds.lpl.arizona.edu/PDS/EXTR...RED.abrowse.jpg


Here is a degraded example (top right):

http://hirise-pds.lpl.arizona.edu/PDS/EXTR...RED.abrowse.jpg


One big example and some smaller ones:

http://global-data.mars.asu.edu/moc/images/large/S0701971


Many craters, some with a few capes and bays:

http://global-data.mars.asu.edu/moc/images/large/E0500154


Similar one:

http://global-data.mars.asu.edu/moc/images/large/E0201844


Another big example:

http://hirise-pds.lpl.arizona.edu/PDS/EXTR...RED.abrowse.jpg


Phil

[Shaka]

Good Lord, Phil, I never saw so many ugly, irregular craters in all my life!
If my experience with crater photos had begun with these, I would be struggling to explain the neatly circular craters elsewhere as the bizarre anomalies.
Compared to these, Victoria is a model of regularity; its 'teeth' are far more uniform around the whole circumference than just about ANY in your photos!
And I thought I understood impact cratering!
I have a headache. I think I'll go lie down.

[CosmicRocker]

Those appear to me to be more recent impacts into older sediments.

[Doc]

The impacts are likely in old sediments. But how do you know if the impact craters are recent?

[Shaka]

Well...ahem...Conventional wisdom would say that the youngest craters had the simplest, circular, well upraised rim, and a crater depth to diameter ratio close to 0.2 (for small, simple primary craters). That would imply that just about none of the craters in Phil's photos are very young.
What does that tell us about "conventional wisdom"? That's why I have a headache.

[Stu]

Just a dark line on the horizon now...

http://roadtoendeavour.wordpress.com/2008/...rewell-victoria

(well spotted, hort! )

[jamescanvin]

Yes I spotted it yesterday while stitching parts of the Santorini pan - it came as a nice surprise.

[algorimancer]

There is a very readable paper in the current issue (22 May 2009) of the journal Science summarizing the results of the exploration of Victoria, "Exploration of Victoria Crater by the Mars Rover Opportunity", by Squyres et al. No dramatic surprises, but a nice summary.

[alan]

NASA Rover Sees Variable Environmental History at Martian Crater

Instruments on the rover's arm studied the composition and detailed texture of rocks just outside the crater and exposed layers in one alcove called "Duck Bay." Rocks found beside the crater include pieces of a meteorite, which may have been part of the impacting space rock that made the crater.

Other rocks on the rim of the crater apparently were excavated from deep within it when the object hit. These rocks bear a type of iron-rich small spheres, or spherules, that the rover team nicknamed "blueberries" when Opportunity first saw them in 2004. The spherules formed from interaction with water penetrating the rocks. The spherules in rocks deeper in the crater are larger than those in overlying layers, suggesting the action of groundwater was more intense at greater depth.

Inside Duck Bay, the rover found that, in some ways, the lower layers differ from overlying ones. The lower layers showed less sulfur and iron, more aluminum and silicon. This composition matches patterns Opportunity found earlier at the smaller Endurance Crater, about 6 kilometers (4 miles) away from Victoria, indicating the processes that varied the environmental conditions recorded in the rocks were regional, not just local.

http://www.jpl.nasa.gov/news/news.cfm?release=2009-088

[stewjack]

The National Public Radio show and podcast Science Friday has a podcast featuring Steve Squyres that mention the paper.

Mars Rovers, Mars Water (broadcast Friday, May 22nd, 2009)

Researchers published new findings based on data collected by rover Opportunity during its exploration of Victoria Crater in the journal Science this week. The rock and sediment features in the crater, scientists say, indicate that liquid water played an important role in shaping a sizable area of the planet long ago. Victoria crater showed water-driven features similar to those found at other crater sites several miles away.


Direct Download of Podcast mp3 ( 8.3 MB )
http://podcastdownload.npr.org/anon.npr-po...r_104479138.mp3

Jack

[Guest_Oersted_*]

Great listening, thx stewjack.