Originally posted by sonhouse
You have an imagination for sure. It seems to me however you need to go to school and complete your education in science so you don't keep going off the deep end.
Like Hu says, what would generate current on Mars? There is only spotty magnetic fields there, no global field like on Earth which could generate some kind of electrical flow but the main thing ...[text shortened]... units. All pure speculation but our form of DNA I would bet is not the only way to make life.
Is life there based on DNA, if not what?
I may be wrong but my best personal educated guess is that alien life most likely would not have DNA genes but would have genes based on a complex molecule quite similar but not completely identical to DNA.
The bases of this educated guess is the fact that the best hypothesis to date of how life first formed on Earth is that the first protocell almost inevitably must have been RNA based ( because RNA spontaneously forms prior to any photocell ) and with no DNA but then DNA evolved later from RNA so my current hypothesis is that virtually all alien protocells at least start with being RNA based but then later evolution takes over and that less-than-ideal RNA evolves into a better DNA-like molecule but, because there are a vast number of subtle variations on DNA, exactly which variant of DNA evolves is down to chance.
I am also making the assumption here that whatever the chemical building blocks life starts with, life generally sticks with or only makes miner changes to them because I also have the hypothesis that it is very difficult for evolution to change or modify the basic building blocks life. Hence my assumption that RNA would not evolve into something completely different from either RNA or DNA but could instead only evolve into something very similar.
Originally posted by humyI think it depends on the energy conditions of an alien planet, for instance, suppose a planet forms where there is a lot of water and a lot of storms with a lot of lightning and therefore a lot of molecular shuffling around over eons of time.Is life there based on DNA, if not what?
I may be wrong but my best personal educated guess is that alien life most likely would not have DNA genes but would have genes based on a complex molecule quite similar but not completely identical to DNA.
The bases of this educated guess is the fact that the best hypothesis to date of how life first ...[text shortened]... tely different from either RNA or DNA but could instead only evolve into something very similar.
RNA could prove to be only one of a lot of variants that would lead to DNA like structures and could make structures like I talked about, instead of a twisted ladder like our DNA, it could be an enclosed triangular affair or enclosed box.
Time will tell, eh.
Originally posted by sonhouse
I think it depends on the energy conditions of an alien planet, for instance, suppose a planet forms where there is a lot of water and a lot of storms with a lot of lightning and therefore a lot of molecular shuffling around over eons of time.
RNA could prove to be only one of a lot of variants that would lead to DNA like structures and could make struct ...[text shortened]... like our DNA, it could be an enclosed triangular affair or enclosed box.
Time will tell, eh.
Time will tell, eh.
Yes, we will just have to wait to see how that one end up in the next few weeks.
Originally posted by sonhouseI used to cast bronze artwork. We would sometimes cast solid pieces. The solid pieces would cool on the outside first and would have enlarged grain structure and voids in the middle. Could it be that mars has cooled enough that the center has voids and the water that was once on the surface has trickled to the interior?
I would imagine at some depth if there was ice there would be liquid water also, maybe even underground rivers.
- Joined
- 18 Jan 07
- Moves
- 12477
Originally posted by joe beyserErm... unlike bronze (unlike most other materials, in fact), water expands when it freezes...
I used to cast bronze artwork. We would sometimes cast solid pieces. The solid pieces would cool on the outside first and would have enlarged grain structure and voids in the middle. Could it be that mars has cooled enough that the center has voids and the water that was once on the surface has trickled to the interior?
Richard
2 edits
Originally posted by Shallow BlueStill, it is pretty well accepted there is water ice under the surface. Just how much has to be sussed out but it is there, proven. I imagine when surface water started evaporating, the atmosphere itself was deteriorating at the same time so they bootstrapped together to make for a dry planet. Dry on the surface, that is.
Erm... unlike bronze (unlike most other materials, in fact), water expands when it freezes...
Richard
The biggest problem was no magnetic shield to keep out solar storms and such, ionizing the upper atmosphere and then out into space on a continuous basis.
My guess: 90% of the water went up and out and 10% went underground. My guess only.
Originally posted by sonhouseWikipedia lists more possible causes:
The biggest problem was no magnetic shield to keep out solar storms and such, ionizing the upper atmosphere and then out into space on a continuous basis.
Possible causes for the depletion of a previously thicker Martian atmosphere include:
Catastrophic collision by a body large enough to blow away a significant percentage of the atmosphere;[8]
Gradual erosion of the atmosphere by solar wind;[9] and
On-going removal of atmosphere due to electromagnetic field and solar wind interaction.[8]
Mars's low gravity allowed the atmosphere to "blow off" into space by gas-kinetic escape. [10]
1 edit
Originally posted by sonhouseTo my understanding it is the moon (amongst other things) which makes Earth
I think it depends on the energy conditions of an alien planet, for instance, suppose a planet forms where there is a lot of water and a lot of storms with a lot of lightning and therefore a lot of molecular shuffling around over eons of time.
RNA could prove to be only one of a lot of variants that would lead to DNA like structures and could make struct ...[text shortened]... like our DNA, it could be an enclosed triangular affair or enclosed box.
Time will tell, eh.
so unique.
There is a theory upon how another object, (approximately the size of mars) collided
with the earth some billions of years ago and left a satellite fragment.
http://en.wikipedia.org/wiki/Giant_impact_hypothesis
What is so important about this collision is how the impact left deep ridges and
grooves upon the Earth's crust which allowed for the containment of surface water.
Originally posted by twhiteheadThat last is one of the biggest problems on Mars, coupled with the lack of magnetic field, or perhaps the extinction of an existing magnetic field. It just didn't have the mass of Earth or Venus on which to hold an atmosphere gravitationally, the ions in the upper atmosphere would have had greater than escape velocity simply through interaction with the solar wind. If it had a magnetic field as strong as Earth's, it would have been able to retain a LOT more atmosphere. The gravity on Mars is barely twice that of our moon, like 1/3 of Earth so ions that would be more or less forever trapped by Earth or what you see on Venus, those same ions zipping around would have had a velocity greater than the escape velocity of Mars.
Wikipedia lists more possible causes:
Possible causes for the depletion of a previously thicker Martian atmosphere include:
Catastrophic collision by a body large enough to blow away a significant percentage of the atmosphere;[8]
Gradual erosion of the atmosphere by solar wind;[9] and
On-going removal of atmosphere due to electromagnetic fi ...[text shortened]... w gravity allowed the atmosphere to "blow off" into space by gas-kinetic escape. [10]
Personally I don't think Mars was hit by something so massive it destroyed the atmosphere, I think it was just its small mass coupled with no magnetic shield doomed the place.
It is interesting, the concept that life could have begun on Mars and some asteroid impact blowing off enough rock with bacteria in it to have made it all the way across space which would have taken millions of years and the meteorite crashing into a young Earth and starting life out here like that, so if that were true, we would all be Martians.
If later explorers find life on Mars, the tale will be told in the kind of life it is, would it be based on DNA like ours or something completely different. If it was based on DNA, that would suggest a deep connection between life on Earth and life on Mars.
If not, the field would be blown wide open, say if the DNA equivalent was shaped like a twisting cube instead of our twisting ladder.
Originally posted by Shallow BlueI was speaking of the magma cooling. Mars having much less mass than earth and being in a more distant orbit from the sun, the interior should have cooled faster. If there was shrinkage of that material causing voids at a time there was liquid water on the surface, maybe it trickled down before the surface got too cold. Hard to think the water would have drifted into space unless gravity stopped. We do get mars rocks on earth because of meteor blasts and the solar wind may wisk some away but not all of it.
Erm... unlike bronze (unlike most other materials, in fact), water expands when it freezes...
Richard
Originally posted by joe beyserWater itself often causes cavities in rock as some rocks are soluble.
If there was shrinkage of that material causing voids at a time there was liquid water on the surface, maybe it trickled down before the surface got too cold.
Hard to think the water would have drifted into space unless gravity stopped. We do get mars rocks on earth because of meteor blasts and the solar wind may wisk some away but not all of it.
As sonhouse points out, the gravity is simply not strong enough to hold on to it. We are talking about water vapour in the atmosphere, not liquid surface water.
Originally posted by twhiteheadSo gravity on mars can hold onto CO2 but not water vapor? CO2 is heavier than water vapor and a lower pressure will cause water to vaporize at a lower temp, but still hard to believe it all left the planet. A comet has enough gravity to hold onto its vapors even though it trails out.
Water itself often causes cavities in rock as some rocks are soluble.
[b]Hard to think the water would have drifted into space unless gravity stopped. We do get mars rocks on earth because of meteor blasts and the solar wind may wisk some away but not all of it.
As sonhouse points out, the gravity is simply not strong enough to hold on to it. We are talking about water vapour in the atmosphere, not liquid surface water.[/b]
3 edits
Originally posted by Thequ1ckCorrection to previous post. Grooves in Earth's crust allow us to have land, not contain surface water.
To my understanding it is the moon (amongst other things) which makes Earth
so unique.
There is a theory upon how another object, (approximately the size of mars) collided
with the earth some billions of years ago and left a satellite fragment.
http://en.wikipedia.org/wiki/Giant_impact_hypothesis
What is so important about this collision is how ...[text shortened]... ridges and
grooves upon the Earth's crust which allowed for the containment of surface water.
When you add this on to the HUGE probabilities of distance from sun etc that allow
for life. The odds are...well....astronomical!
With this in mind, it has to be pretty pointless looking for life similar to our own.
