Ian Goddard wrote in message . ..
"Paul Henney" wrote:

Hi,

I'm a geologist (igneous petrologist) and I'm totally baffled by the recent
microscopic images from Opportunity.

This is clearly a very fine grained chemical sediment with occasional
detrital grains (Blueberries). Its not detrital, not bedded.
Totally weird.


My hunch is that the Martian "blueberries"

http://www.jpl.nasa.gov/mer2004/rove...s/image-1.html

are meteorite-impact spherules that form as minerals vaporized by
meteorite impacts recondense and cool in the atmosphere. Spherules,
also known as microtektites, are even predicted to be common on Mars:

http://www.lpi.usra.edu/meetings/5thMars99/pdf/6039.pdf

They are also found on Earth

http://gisp.gi.alaska.edu/tutorial/tekt.htm
http://geology.rutgers.edu/spherbig.gif
http://geology.rutgers.edu/brimages.html

and throughout the K-T boundary that's believed to be debris from a
massive meteorite impact that may have wiped-out the dinosaurs. The
world-wide distribution of spherules at the K-T boundary is considered
to be strong evidence that the K-T boundary was caused by a meteorite
impact versus a massive volcanic event, which should not distribute
spherules throughout the world. It's also possible that the Martian
"blueberries" might be volcanic spherules. Either way, in my view
there's a strong similarity between the "berries" and spherules.


Hi Ian

I suggested the same thing a couple of weeks ago on another thread
here on sci.astro (wind erosions farms is the thread name I think) Im
glad to hear someone concur with me that it is meteor impact. Did
these recent microscopic images you refer to come out in the last few
days only? I hope so as it means I predicted the phenomena you suggest
before this `blueberry info` was available.
Below is the quote from my post from sci astro from about a week and a
half ago....

If the nodules are on the surface maybe...
Going back to the explosion idea I suggested before,..
I dont know if there are enough craters to allow the statistical
chance of finding these all over Mars and at the lander site but I was
thinking a bit more on maybe how they were created, if by an impact
crater event.
If lets say at impact either water or another gas either present as
liquid or solid in the projectile or in the sediment ,were to be
instantly heated to extreme high tempratures. The material that the
nodules is made of could also mix in that instance with that breif
extremely hot gas cloud above the explosion site sort of like a soupy
particulate mix of gas and liquid droplets mixed with the nodule
element. As it is forced out and away from the site at great speeds by
the explosion the mixture is cooled rapidly as it spreads out into
the presumabley extreme cold of the martian atmosphere. This would
cause the cloud to precipitate out in a sense into droplets , all
small , and very rapidly `freeze` into shape in seconds as they are
speeding through the extreme sub zero martian atmosphere and then
presumably are hard all consistently sized small frozen droplets when
they land around the impact site. They then over time `freeze dry`
out the liquid water (or whatever liquid it is) in the sun and climate
to the present state of a nodule consisting of just the original
material which could have initialy pre impact have been a powder or
granular material like glass once was sand?
One idea would be to look for similar phenomena at old nuclear test
sites as in essense I am suggesting they a sandy or powdery medium
mixed in with a liquid and as baked `nodules in extreme rapid heating
, cooling and speeding `event` through a cold atmosphere to get the
small sized droplet shape. Maybe the thinner matian atmospher would
aerodynamically produce a rounder projectile rather than the heavier
earth atmosphere which would have elongated the droplets .As I
mentioned this phenomena may also occur similarly at nuclear test
sites.
They then erode by wind into the observed sandy mixture
Sean