Mars Volcanoes May Still Erupt

Q3vi1 writes "Space. com reports, Images from a European space probe reveal recent glacial deposits and lava flows on Mars that suggest the red planet is more active than many scientists had thought."

Comments

Re:Okay...

[tloh]

If you know you are not interested, why do you desire an explanation?

For those who *are* interested, this can have any of several significance. According to an installment of NOVA on PBS called "Origions", a popular theory of planatary evolution holds that a hot molten interior in an inner planet such as Earth is responsible for creating the planetary magnetic field that shields the planet from the abrasive effects of the solar wind. Without this magnetic shield, the sun's radiation strips away the planet's atmosphere and other volatile compounds such as water. It was thought that Mars, being smaller than Earth, had a core that cooled and solidified more quickly and lost it's magnetic field early in it's life. With not magnetic field to shield it's surface, the atmosphere thinned and water became scarce.

If Mars happens to be more geologically active than we once thought, another theory will be needed to account for the signs of a wetter martian past. Quite possibly, we need to reevaulate the level of protection offered by the molten core of our own Earth against the erosive effects of the solar wind.

Re:Hmm interesting

[TheGavster]

I see creationism as a way of just not bothering to figure out the past. We don't have a good idea of what happened more than a few thousand years ago. Solution? The world simply didn't exist. Where did the universe come from? God made it. Even if they acknowledge something like the Big Bang, there's still an orign for that initial mass, once again the notion of a God relieves them of a need to learn more.

Re:Molten core

[Aglassis]

You said "If it's as recent as 4 million years that would put to bed the dead Mars theory. The idea that Mars lacks a molten core. If there was magma that recently there would still be a molten core. It would take hundreds of millions if not billions of years to go from volcanic to a cold core. There would almost have to be liquid underground water. Good news for life and also water for explorers."

For the core to be molten there is a non-linear temperature and pressure dependance. On Earth, the inner core is solid and the outer core is liquid even though the temperature of the inner core is higher. This is because the increased pressure at the inner core forces iron to stay solid while the decreased pressure at the outer core boundary allows it to melt. The pressure at the core of Mars should be less because of the smaller size of Mars, but the core temperature will almost certainly be lower because of the higher surface area to volume ratio (more heat can be radiated into space per the given mass of the planet). This makes it difficult to say for sure whether it is solid or liquid (though the lack of a magnetic field makes me inclined to believe that its solid).

It should also be noted that the mantle is solid on Earth (yet still deformable) yet liquid magma is found near the surface (and lava on the surface). This is for the same reason described (since the pressure is much less near the surface). A solid core can still allow vulcanism.