Hello everyone, Ive been reading the forums here for a few months now. Theres an incredible amount of knowledge here and I appreciate everyone sharing here..I do have a few questions related to planets..

1st, are any of the volcanoes active on mars?

If we are looking for any signs of life on mars would we find it closer to the poles where there is ice?

Do we know or is there enough information available for us to determine if there were ever anything similar to our earths plate tectonics on mars?

What keeps earths core from cooling if anything? Will it eventually cool and will our own plate tectonics cease?

Do we currently have the capabilities to measure the oxygen output of our plants to determine how muh life we can sustain here on earth? I would imagine that there is not an infinant supply of oxygen and as we develope land and cut out our plants and trees that create oxygen that the total amount of oxygen available must also decrease.

Sorry for all the questions right off the bat but i figured if anyone has the answers you will..

well, to briefly address one of your questions: it's not land plants that produce most of the free oxygen we breathe, but water(ocean) organisms. i seem to remember that the amount of free oxygen produced by plants on land is not crucial to maintaining the level of free oxygen life on earth requires... but if you do a Google on this subject you'll probably find some more trustworthy references than just my say so...

and welcome to the Board!


[edited to add belated welcome ops: and to remove typo]

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Insulation, of course. The side effects of plate tectonics--volcanoes, earthquakes, sea-floor spreading--work to allow some heat to escape faster, but there is a lot of it left yet.

No. Mars has many impressive volcanoes, but they are all extinct.


NASA planned on doing this with the Mars Polar Landers in (I think) 1998, but due to some metrics to US measurement issues ... the spacecraft died. NASA doesn't really have any future (to 2011) plans of exploring the poles (see http://nssdc.gsfc.nasa.gov/planetary/mars_future.html ), but frozen microbial life, as far as I know, is a distinct possibility.


There are Marsquakes. Viking 2 carried a working seismometer and it recorded one marsquake while it was operational.


I'm pretty sure that heat left over from the formation of the planet has dissipated. I believe that what keeps the core hot now is the decay of radioactive elements.


To repeat what Morrolan said, it isn't the land, but it's the water plants that produce most of the free oxygen in our atmosphere. Thus, logging etc. does not have a sizeable affect on the oxygen in the atmosphere (someone please correct me here if I'm wrong). Studies have been done to measure the oxygen output, but I have no idea what they showed. My thinking is that we have a wonderful cycle going on that recycles the oxygen and keeps it fairly constant. Related, but probably not what you were wondering, is that the 70% N2 23% O2 atmosphere that we currently enjoy was not Earth's original atmosphere, but more of a tertiary one caused by plants. Oxygen was the first "atmospheric pollutant" of life. Many evolutionary biologists believe that it was the dramatic increase in atmospheric oxygen that allowed for some of they huge and rapid diversifications in lifeforms earlier in the planet's history.

I hope these answers help, and for the most part I'm pretty sure they're correct. You probably want to check me on that last and next-to-last answer, though.

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Even tectonically dead bodies can have quakes--Earth's own moon, for instance. They've been correlated with tidal stresses, I understand.
No, just the opposite. Most of the internal heat is probably from the formation of the planet--radioactive heat is more important in the crust.

Oops, I never did answer the question about techtonically active or not, just said there was a quake detected. This post box is just too small!!

As to the latent heat, thanks for correcting me. I knew I was either way right or way wrong. :^o

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(Emphasis mine)

Um... The atmosphere (specifically, the troposphere, minus water vapor) is 78% nitrogen, 21% oxygen, and 1% argon, by volume. Water vapor varies a lot, but is generally less than 3%. By weight, the same dry air is 75.5% N2, 23.2% O2, etc.

See this site for reference.

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One nice thing about being a meteorologist who also likes astronomy is that the sky is always interesting!

earthgazer,

Welcome to the board!

Like the handle, I picture someone who watches where they're walking!

BTW, since it now appears that there is a considerable amount of water (probably frozen, but in some cases maybe not) just under the Martian surface all over the planet, we just need to be able to drill down into it to see if there are any habitats down there.

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And I always like to point out that the 21% of oxygen in our atmosphere is mostly fossil oxygen, put there by plants millions of years ago; it is not being maintained by our current biosphere. Neither today's trees or today's ocean phytoplankton are responsible for the production of most of the oxygen we breathe, and you could gather the entire world's biomass together and burn it without making much of a dent in the world wide oxygen level.

Not that I am suggesting that you try it, of course; that would increase the CO2 component to a deadly level.

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Yup, it's real neat that the first couple a billion years ocean plants were producing this toxic substance, diatomic oxygen. Later, other organisms found a use for all the 'poo'.

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Actually, it was Mars Climate Orbiter that engaged in a "controlled flight into terrain" due to conversion problems. Mars Polar Lander died due to premature shutdown of its landing rockets, at least that's believed to be the most likely explanation.

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I think it will eventually cool, but for now the heat energy from radioactivity helps keep it warm. This was actually a serious issue in the 19th century, when geological evidence indicated a billion-years-old Earth but there was no known mechanism to keep either the Earth warm or the Sun burning for such a length of time until radioactivity was discovered near the end of that century.

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Thank you for the welcome. The handle actually came to mind when viewing a photo of the earthrise from the Moon. I love that picture.

Isnt there a european mission around mars now that is capable of doing imaging into the Mars crust to find water or potential water deposits?

If the level of oxygen is not being maintained than is there someone out there who has figured out a formula to determine the amount of oxygen that we are losing annually?

Thank you for the response. Once again I learn something new..

ok I goggled and found the answer!

http://members.shaw.ca/tfrisen/is_th...ugh_oxygen.htm

I dont understand most of the formulas but the answer is about 15,000 years before the oxygen level drops to a level that humans cannot breath. This doesnt take into account for the burning of coal, wood natural gas ect..

Woops. I meant to check that before I posted. I usually use http://nssdc.gsfc.nasa.gov/planetary...earthfact.html as my reference for this. Remind me not to post in the late late evening. #-o

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Are you sure?? Oxygen is 20% of the whole atmosphere. It's been around for billions of years. I don't think it's going to go away in 15,000 years.

It wont go away in 15,000 years it will drop to a level(18%) that we as humans cannot currently breath. according to the link above. I've been doing more googling on the subject and there is certainly a vary wide range of opinions on it.

Of course, that figure assumes current or increased levels of combustion reactions taking place for those full 15,000 years. It'd also be accompanied by an incrase in CO2, which would help stimulate plant growth. The Earth's self-regulating. As we try to destroy its ecosystems, the ecosystems try to restore themselves. We may be winning that battle, but Mother Nature's going to put up more and more of a fight as the war drags on.

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Absolutely; that link is garbage.
If you burnt all the world's biomass the oxygen level would go down to about 20%.Then you would need to dig up all the worlds fossil fuels, which would last about 500 years at tops; you still haven't gotten the oxygen down below 18%. 18% oxygen would be perfectly breathable at sea level except for the increased CO2 level.

The Earth's atmospheric oxygen started as CO2, but the carbon has been removed by plants, and buried in sedimentary rocks; you would need to grind up the surface layers of the Earth to get all that carbon back to get rid of the oxygen.

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I personnaly believe the Earth is self regulating and will correct itself under any circumstances. I guess Im just looking at one aspect of this and trying to back up my own beliefs by understanding how the regulation of Oxygen occurs.

According to this paper, the oxygen level of the earth has varied from a low of 15% to a high of 36% over the past 550 million years. The high point was about 300 mya, and the low point occurred as recently as 190 mya. A graph of the past 550 my is shown here.

It appears that there are a number of competing processes going on that add and/or subtract oxygen from the atmosphere.

Yes; 300 million years ago the oxygen levels were vey high, and this was the time of the giant arthropods; one giant spider, Megarachne, the size of a cat, is represented by a fossil in my local museum.
Today such creatures would suffocate.

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Humans have no problem breathing a non-toxic 18% oxygen atmosphere of the proper density.

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