I thought this would interest some on this board, of course its not definite so take it with a grain of salt, no pun intended................ In case you are wondering why salt would mean the absence of microbes: link
Interesting,you'd think finding salt would mean there may have been life at one time.If our planets oceans were to "dry up" wouldn't there be vast amounts of salt in the soil as well? Or am I not getting this?
The key here is "Earth-like," so it's not out of the question. We don't have to look far for a reason to support the idea that it's possible. The Dead Sea is so named because it is nine times as salty as the ocean and it was once thought that it couldn't support life. However, there is a type of microbe that lives in it.
the article states that by their calculations the amount of salt x amount of years ago would be higher then even the highest salt content on earth, thus making it unlikely for earth like life to exist.
well yes and no. We know how earth life evolved thus we start by looking for planets close to what we believe our planet was/is like that allows it to support life if that makes sense. Something could possibly have come to exist in different atmospheres, circumstances, etc, but we thus far do not know of any. So we go with what we know. And what we know is it seems that, with little to no water life can not exist, thus too much salt would spell bad news for any young organism.
Life will find a way. Extremophiles can exist under the most severe of conditions.Who is to say they cant exist in even more severe conditions in other celestial bodies. http://en.wikipedia.org/wiki/Extremophile
Wait! Did you read what I wrote? If there is a microbe that lives in the Dead Sea, why is it impossible for another evolve in conditions that are just a bit more harsh?
not to speak for Lucky Mike, but I think his point is the odds are significantly reduced for life "as we are familiar" to happen.
Hmmm well maybe we interpreted it a bit different, but it doesn't seem to me that the conditions are just a bit different................. and as cnc said I'm not saying its impossible at all.........
There may have been life there before solar radiation caused by a polar reversal resulted in the atmosphere boiling off. It could happen on earth too . BTW this is just a theory .
if that were the case Derek, we would see mass extinctions coinciding with the reversals.. and there have been a BUNCH, but to my knowledge, no link has ever been established.
I guess I see the beef with what I said. I fixed it, the conditions would make earth life less likely to exist is what I should have said or unlikely.
I read somewhere that the reversals occur on Earth every 300,000 years or so and that the magnetic field on the earth weakens before it happens
yup thats what I read as well. So some scientists believe currently we are headed for another pole reversal.............. I hoping it will wait a couple of hundred years.
I get Science magazine and will be interested in reading the article and finding out how they calculated the salt concentration -- especially in light of the fact that very little of the planet has been directly sampled for sodium chloride. Also, when water evaporates, it leaves behind any type of salt in the solution. Unless you know the current NaCl concentration and how much water that NaCl was originally dissolved in, there would be no way to accurately calculate the NaCl concentration in Mars waters. Just a couple more points from the microbiology side of the argument: There is a reason that earth microbes won't grow in any higher concentration of salt than what is found on earth: Evolution. Unless a microbe has a need to modify enzymes or develop ways to deal with high solute concentrations, it won't happen. Since 99% of the earth's microbes found in nature can not be cultured in the lab, you can not reasonably say that no earth microbe can survive in the presumed salt concentrations on Mars. You can only say that of the 1% of know microbes, none of those that have been tested, can grow in the presumed Mars NaCl concentrations.
Well, the first origins of life on Earth existed as microscopic organisms that thrived off of the harsh, underwater sulfuric environments found near the hydrothermal vents, so why isn't life in harsh, salty conditions possible?
Alright, I'm not as intelligent as some of you on this topic which is why I have a question. Isn't the climate of Mars made up of chemical substances which would make it difficult to breath and have life? Or am I mixing it up with another planet? If so, then how could have life possibly existed in the past? I believe the seasons are similar to Earth's there but I can't get around the chemical substances that are in the climate. Sorry if I made it difficult to comprehend, tried my best to make it make sense.
yes, the atmosphere is not what we would need to live. I can't remember what chemicals it's made up of right now. Having said that at one point earth's atmosphere was not what it is today and I believe bacteria lived on earth, so yes life can exist in different scenarios. At least thats what I remember having learned. If I am wrong someone can correct me.
I'm curious Unlucky, can bacteria or virus's survive on meteors or planetary debris? In the 1990's a rock was found in Antarctica that supposedly came from Mars that showed signs of such life, the claim was later debunked, but I'm curious as to if a huge asteroids hit the earth if is possible that life could be transfered to Mars (or vice versa) in such a manner?
Not to sure bro Celtkin would probably be the better one to ask that. I'm a poser when it comes to biology he's the expert. I've wondered the same, though. Heres another asteroid that showed signs of life: Here's a link link
The Martian atmosphere is primarily carbon dioxide and would be impossible to breath. The early earth atmosphere had higher than current CO2 levels as well. As photosynthetic microorganisms and plants converted the CO2 to glucose and oxygen as a waste product, this allowed the rise of aerobes.
It is quite possible with spore-forming bacteria. Bacterial spores are resistant to heat and radiation and can survive centuries without water. Bacillus pumilis has already shown itself capable of surviving intense radiation, dessication and heat. In fact, B. pumilis was isolated from the aluminum surface of the Mars rovers before the launch. Many labs, including the one I am in now, are looking at B. pumilis as a model organism for survival in Mars soil. Viruses on the other hand are not as likely to survive. Viruses are coated with a protein that protects its nucleic acids. That coat is very sensitive to heat. I am not sure what effects ionizing radiation would have on viruses but I would assume that it would generate mutations of the viral genome.
That was the epoch when our oil was created.. the planet was flushed with primitive greenery. It was this early oxygen that precipitated the iron out of the oceans.. literally rusting it out of solution, creating the deposits we strip mine today. on the Martian metorite that has interesting formations upon it. It was not "debunked" as it was never said to be organic creations. The lab that did the initial work tendered a hypothesis entertaining that microbial action may have created the formations, then they turned everything over to the rest of the world and said have at it, we need your opinions... in the end, the overwhelming opinion was although the formations have many similarities with microbial evidence here on earth, they felt it was very unlikly that was the cause of what they examined. To my knowledge, noone but the media was really hyping this sample as being the "evidence" of extraterrestial life, they read through the list of possible causes and ran with the alien lifeform story.
Interesting that the Mars craft itself had to be looked at in order to keep from violating the dictum of "what you study you inevitably alter". Would Bacillus survive a trip to Mars on the Rover equipment? Has all of the Mars Equipment been checked as completely?
Yes, many Bacillus species, in the spore form, would survive the trip to Mars and would survive the entry through the Martian atmosphere and, quite possibly, on the surface, though I doubt that the spores would be able to germinate and would therefore remain dormant. Our lab participated in the scrubbing of both landers. The work was done by Nick Benardini who just graduated with his Ph.D. and went to work for JPL on the Mars project in California. NASA knows the danger of forward contamination and does everything it can to prevent the transport of Earth microbes to other planets.
