The Conjunction Plan Options

[CosmicRocker]

... Are we really still on Erebus rocks?

Interesting... If I am reading the dips correctly, these rocks must be younger than those at Erebus, and younger than those near Beagle. I think I am seeing small spherules in the bedrock, so what does that mean to the groundwater hypothesis? ...yet a higher ancient water table, or a more recent water table that crossed the dipping beds? You have got to love extraplanetary roving cameras and MMB.

[Doc]

The spherules seem to be embeded and arranged in neat little strings of pearls. And the spherules seem to be concentrated in crest like structures in the rock much like the rocks at Eagle crater. I believe these rocks are of the eagle unit. I am particularly interested in what the brine splat hypothesis has to say. (Admin: I don't wish to start another debate;-)

[Astro0]

You'll be happy to know that the next scheduled (DTE) tracking pass with Opportunity will be through the Canberra DSN complex at:
2100 UTC Tuesday 16th - 0135 UTC Wednesday 17th December 2008.

I think that'll be an appropriate point to start a new thread as Opportunity begins the next leg of its journey to Endeavour Crater

[climber]

Thanks Astro!
So, where does today "download" come from? http://qt.exploratorium.edu/mars/opportunity/

[mhoward]

So, where does today "download" come from? http://qt.exploratorium.edu/mars/opportunity/

Images as recent as sol 1732 - four sols ago. Not "DTE" (direct-to-Earth), I guess, but information relayed through Odyssey. Still, I think that counts as good "Opportunity is still with us" news? I hope?

[Astro0]

Climber: So, where does today "download" come from?

Odyssey. We still have contact with ODY, MRO despite conjunction.
I was only noting the first DTE comms with the MERs following conjunction.
Actually we have a few DTEs with both rover over the next few weeks.
So we'll getting our information from a first hand source.

Astro0

[Stu]

Interesting rock visible in today's pancams...



Meteorite? Dunno... some smaller rocks that look like it are nearby... pretty little thing tho...

3D version here...

[nprev]

Sure looks like a meteorite to me, Stu; even seems like it's got the 'fingerprint' indentations often found on the iron-nickel ones!

[Shaka]

Since it's Santorini, we should have the spectrometry now to determine that.

[CosmicRocker]

... We still have contact with ODY, MRO despite conjunction.

That's good to know, and interesting, too.

[jamescanvin]

As Shaka says that rock is Santorini itself, so hopefully we'll know what it is soon.

Would it be a surprise if the cobbles turned out to be meteorites? I haven't been following the theories too closely.



It is nice that some data has continued getting through so we can keep our minds at rest about the health of our girls.

[Shaka]

Undoubtedly, some cobbles are meteorites, that's been confirmed, but many more should be variously-modified impact ejecta from all over the planet. The meteors are flying around in space; the new craters are there, so the ejecta must be as well. It surely erodes away in time, but must persist to some degree at the present. It will represent pieces of the Martian surface rocks, and should erode at a similar rate, except insofar as it is metamorphosed by the shock of impact. Mild shock, at some distance from the impact point, may fracture and, hence weaken the rock, but heavy shock near the impact may variously melt ejecta to glasses. I'm sure the relative abundance of meteorites, ejecta and local rock will vary considerably from place to place, but in general I would guesstimate the meteorites to represent less than one percent of the cobbles. Distinguishing which are which may be difficult with the MERs, but we should be keeping a lookout for ablation surfaces and glassy tektite forms.

[Doc]

Many cobbles that Oppy encountered back at Erebus and between the crater and Endurance were in the form of little piles. Those should mark the location of now eroded craters (right? ). The fact that Santorini is found sitting all alone implies that it was hurled from somewhere else and could potentially bear impact melts I believe.

[Shaka]

I'm still waiting for MIs of Santorini, which could be enlightening, but the spectrograms are also key data.
My interpretation of some of the rubble piles north of Victoria was that they were the remains of large (meter-scale) clumps of ejecta thrown out of a fresh crater like Beagle, and shattered on impact with the plain. (It's a pity we didn't have the time to study the rubble close-up - maybe next time.) Generally, the eroded craters in the meters-scale range that we have seen, have been flat depressions with a few or no rocks near the center (perhaps the residue of the impactor). A pile of rubble with no sign of a circular rim around it is IMHO unlikely to be a primary crater, or even a high velocity secondary.

[Stu]

"Santorini" close up...

http://cumbriansky.files.wordpress.com/200...ppy-dec13c2.jpg