For fun, you might want to compare the rocks in the original Mars image with these:
http://aslo.org/photopost/data/508/8200 ... ow_res.jpg
http://www.boulder.swri.edu/~bullock/As ... olites.gif
http://www-cyanosite.bio.purdue.edu/ima ... trom13.jpg
These are stromatolites and they are composed of cyanobacteria and the grow a mineral structure similar to coral. The resulting structure is porous or layered or even vesicular. You would not be able to distinguish between these stromatolites and the rocks in the Mars image. It is consistent with the past oceanic history of Mars and it is not at odds with any physics.
Note that stromatolites would also have growth, like the ring structures in the vesicular rocks in the Mars image. In other words, they are consistent in more than one way with the image contents and the history of the planet.
For Martin, if you posit an explosive source of the rocks from a volcano, then you must have a material in the volcano that can change state from solid or liquid to a vapor in an explosive manner. Also remember that this material would leave traces in the chemistry of the planet and atmosphere. Water fills both requirements easily and is known as a product of heating magma.
Things are different on Io because its volcanoes are mostly sulfur and contain gaseous sulfur compounds in excess. Things are different on Triton because nitrogen is the active material that is vaporizing, producing the explosive force. Things are similar on Enceladus because water is the vaporizing agent. For any terrestrial body we will expect that magma that formed from the same materials (the protoplanetary nebula) will contain similar materials.
Ammonia and methane trapped underground and heated in molten rock and iron will form water vapor, nitrogen, carbon dioxide, graphite and petroleum. That part of the chemistry is pretty simple. Because of this, we have a source for much of our atmosphere and water right away. It also explains
how the water is emerging from volcanoes- it was formed in the same place the magma was molten.
In summary, we would expect that most any terrestrial planet will have water as a major part of its volcanic chemistry.
For Harry, I must agree that since our planets all formed from the same nebula, and we are told that the sun was not yet lighted until after the planets formed, then we must assume that the composition was likely uniform throughout when the inner planets came to be. Only later, when the sun lit and produced solar wind and light pressure, did any significant separation of those materials occur. It would think that the gas giants were pretty good samples of the early nebula, barring changes in their atmospheres through chemistry.
This also explains why Jupiter is so dry - not being a terrestrial world, it could not have formed as much water through magma processes as the terrestrial worlds did.
In one stroke, we see how the Earth has so much water and Jupiter does not, and it explains why volcanoes on Earth emit so much water. It also points to the thought that Mars probably has underground springs even today as its water seeps up through the mantle and emerges. Estimates are that there are at least ten oceans' worth of water still trapped in our mantle today on Earth.
For fun, you might want to compare the rocks in the original Mars image with these:
[url]http://aslo.org/photopost/data/508/82005_1005Ningaloo0118_stromatolites-Shark_Bay_low_res.jpg[/url]
[url]http://www.boulder.swri.edu/~bullock/Astro/stromatolites.gif[/url]
[url]http://www-cyanosite.bio.purdue.edu/images/lgimages/strom13.jpg[/url]
These are stromatolites and they are composed of cyanobacteria and the grow a mineral structure similar to coral. The resulting structure is porous or layered or even vesicular. You would not be able to distinguish between these stromatolites and the rocks in the Mars image. It is consistent with the past oceanic history of Mars and it is not at odds with any physics.
Note that stromatolites would also have growth, like the ring structures in the vesicular rocks in the Mars image. In other words, they are consistent in more than one way with the image contents and the history of the planet.
For Martin, if you posit an explosive source of the rocks from a volcano, then you must have a material in the volcano that can change state from solid or liquid to a vapor in an explosive manner. Also remember that this material would leave traces in the chemistry of the planet and atmosphere. Water fills both requirements easily and is known as a product of heating magma.
Things are different on Io because its volcanoes are mostly sulfur and contain gaseous sulfur compounds in excess. Things are different on Triton because nitrogen is the active material that is vaporizing, producing the explosive force. Things are similar on Enceladus because water is the vaporizing agent. For any terrestrial body we will expect that magma that formed from the same materials (the protoplanetary nebula) will contain similar materials.
Ammonia and methane trapped underground and heated in molten rock and iron will form water vapor, nitrogen, carbon dioxide, graphite and petroleum. That part of the chemistry is pretty simple. Because of this, we have a source for much of our atmosphere and water right away. It also explains [i]how[/i] the water is emerging from volcanoes- it was formed in the same place the magma was molten.
In summary, we would expect that most any terrestrial planet will have water as a major part of its volcanic chemistry.
For Harry, I must agree that since our planets all formed from the same nebula, and we are told that the sun was not yet lighted until after the planets formed, then we must assume that the composition was likely uniform throughout when the inner planets came to be. Only later, when the sun lit and produced solar wind and light pressure, did any significant separation of those materials occur. It would think that the gas giants were pretty good samples of the early nebula, barring changes in their atmospheres through chemistry.
This also explains why Jupiter is so dry - not being a terrestrial world, it could not have formed as much water through magma processes as the terrestrial worlds did.
In one stroke, we see how the Earth has so much water and Jupiter does not, and it explains why volcanoes on Earth emit so much water. It also points to the thought that Mars probably has underground springs even today as its water seeps up through the mantle and emerges. Estimates are that there are at least ten oceans' worth of water still trapped in our mantle today on Earth.