Phoenix color photos

Newest goodies from the north polar region of Mars:
http://www.jpl.nasa.gov/news/phoenix/main.php
Soil color looks very similar to what the two MERs found at their
landing sites.
Tan/orangish iron oxide soil as expected.
Far more small rocks in the soil than at either of the MER sites.
Small-scale rough terrain quite different than one would find on Earth
outside of an area of severe volcanic action unaltered by any sort of
modifying via weathering, glaciers, or rivers.
On Earth, you can find soils like this in the barren areas of the
northern African rift valley, as well as the volcanic fields that sit in
the western areas of the Arabian Sinai, and that are a extensions of it.

Pat

Pat Flannery wrote:
Newest goodies from the north polar region of Mars:
http://www.jpl.nasa.gov/news/phoenix/main.php
Soil color looks very similar to what the two MERs found at their
landing sites.
Tan/orangish iron oxide soil as expected.
Far more small rocks in the soil than at either of the MER sites.
Small-scale rough terrain quite different than one would find on Earth
outside of an area of severe volcanic action unaltered by any sort of
modifying via weathering, glaciers, or rivers.
On Earth, you can find soils like this in the barren areas of the
northern African rift valley, as well as the volcanic fields that sit
in the western areas of the Arabian Sinai, and that are a extensions
of it.

Which is surprising - at both of Earth's poles wind speed can become
very high indeed (over 100 mph at the south pole), and you'd expect the
rocks to get worn down into a more rounded form by slamming into each
other over tens of thousands of years.... with the far lower atmospheric
pressure being balanced off to some extent by the lower gravity on Mars
that would get the rocks moving round.. This might indicate that the
rocks in the photo are fairly dense and heavy, and therefore not prone
to getting moved around even by very high velocity Martian winds.
In short, more like basalt or obsidian than pumice.
Yet they lie around on the surface - indicating that their average mass
is lower that the soil beneath them - so maybe they are of middle weight
- lighter than the soil, but not so light that the wind can blow them
around.
If I were to take a guess at this right now, I'd say that most of those
small rocks that Phoenix is seeing are ejecta from huge volcanic
eruptions. They're porous, but not so porous and lightweight as pumice.
What makes pumice so lightweight is that the water in the magma that
forms it expands into superheated steam as its ejected from the volcano,
turning it into a rock analogy of Styrofoam.... like popping popcorn as
its shell ruptures and the superheated water in it expands -
simultaneously expanding and cooking the interior material of the corn
kernel.
Without water as an integral part of its make-up, Martian magma may
behave completely differently from its Earthly relative.
The "blueberries" have already been pretty much tracked down as
meteorite splash that cooled into spheres as it fell through the Martian
atmosphere.
These rocks that Phoenix has seen are rough, so that pretty much removes
them from the meteorite-splash created type.

Pat

"Pat Flannery" wrote in message
dakotatelephone...


Pat Flannery wrote:
Newest goodies from the north polar region of Mars:
http://www.jpl.nasa.gov/news/phoenix/main.php
Soil color looks very similar to what the two MERs found at their landing
sites.
Tan/orangish iron oxide soil as expected.
Far more small rocks in the soil than at either of the MER sites. Small-scale
rough terrain quite different than one would find on Earth outside of an area
of severe volcanic action unaltered by any sort of modifying via weathering,
glaciers, or rivers.
On Earth, you can find soils like this in the barren areas of the northern
African rift valley, as well as the volcanic fields that sit in the western
areas of the Arabian Sinai, and that are a extensions of it.


This is an arctic site, the polygons means water freezing and thawing
near the surface due to solar radiation. So the surface is higly modified
by water erosion. This terrain is very much like the Alaska permafrost
not equatorial regions.



Which is surprising - at both of Earth's poles wind speed can become very high
indeed (over 100 mph at the south pole), and you'd expect the rocks to get
worn down into a more rounded form by slamming into each other over tens of
thousands of years


It takes supersonic wind speeds on Mars to lift a 1 mm pebble of the ground
due to the thin air. Only dust and sand move around for the most part.
Rocks should only be eroded by the dust and sand, not by each other.


..... with the far lower atmospheric
pressure being balanced off to some extent by the lower gravity on Mars that
would get the rocks moving round.. This might indicate that the rocks in the
photo are fairly dense and heavy, and therefore not prone to getting moved
around even by very high velocity Martian winds.
In short, more like basalt or obsidian than pumice.
Yet they lie around on the surface - indicating that their average mass is
lower that the soil beneath them


No, it only indicates the soil, sand or dust has blown away, leaving
behind more rubble. Look up the term lag deposit.


- so maybe they are of middle weight
- lighter than the soil, but not so light that the wind can blow them around.
If I were to take a guess at this right now, I'd say that most of those small
rocks that Phoenix is seeing are ejecta from huge volcanic eruptions.


This area was once the bottom of a sea. The northern lowlands are
several kms lower than the highlands


They're porous, but not so porous and lightweight as pumice.
What makes pumice so lightweight is that the water in the magma that forms it
expands into superheated steam as its ejected from the volcano, turning it
into a rock analogy of Styrofoam.... like popping popcorn as its shell
ruptures and the superheated water in it expands - simultaneously expanding
and cooking the interior material of the corn kernel.
Without water as an integral part of its make-up, Martian magma may behave
completely differently from its Earthly relative.
The "blueberries" have already been pretty much tracked down as meteorite
splash that cooled into spheres as it fell through the Martian atmosphere.


What? The latest official explanation is that the are mineral concretions that
formed in a wet layer of soil several meters thick. Only to erode out later
as the water evaporated. Leaving behind the sulfate rich soil you'd expect
from an evaporation salt sea.


These rocks that Phoenix has seen are rough, so that pretty much removes them
from the meteorite-splash created type.


Nothing you said is even close to being accurate.




Pat