NASA May Have Killed The Martians 238
Sneakernets writes "CNN reports that NASA may have found life on Mars via the Viking space probes in 1976-77, but failed to recognize it and killed it by accident. Dirk Schulze-Makuch, a geology professor at Washington State University, says that Mars microbes that the space probes had found were possibly drowned and baked by accident. Other experts said the new concept is plausible, but more work is needed before they are convinced. From the article: 'A new NASA Mars mission called Phoenix is set for launch this summer, and one of the scientists involved said he is eager to test the new theory about life on Mars. However, scientists must come up with a way to do that using the mission's existing scientific instruments, said NASA astrobiologist and Phoenix co-investigator Chris McKay.'"
OMG The title is soooo misleading... (Score:5, Informative)
The title implies that NASA killed off all of the martians, while the article says that if Viking had found a few martian microbes in its sample, it would have killed those.
There's no need for the sensationalism.
Re:old video (Score:1, Informative)
Re:old video (Score:1, Informative)
This is basically a retread... (Score:5, Informative)
Back in the 70's the results of the "chicken soup" (gas exchange) experiment on board the Vikings were frustratingly inconclusive - the resulting single release of gas when combining martian soil with a mixture of likely nutrients could have been produced by several mechanisms: (1) a simple chemical reaction between the soil sample and the "soup", or (2) the death rattles of an organism poisoned by the "soup" or (3) the initial metabolic release of (an) organism(s) that ate itself to death like a goldfish on the nutrient "soup".
Re:OMG The title is soooo misleading... (Score:3, Informative)
Unless all of martian life was conviniently located in just that sample, and nowhere else.
Re:old video (Score:5, Informative)
First, there is an 'energy' definition of life. That is to say, alien life may not be carbon-based, may not use water, may not be composed of cells, and may not have DNA inside of it. However, one of the defining characteristics of life is that it uses energy. It metabolizes, grows, and reproduces. It eats something, somehow. It makes a waste product.
So, if we look at a planet's chemical composition, we can make a good guess as to whether there is life there by looking at its chemistry. If there are living things there, they will be making reactive chemicals. From outer space, we could tell that the Earth has a lot of metabolic activity in it, because the sky is mostly highly reactive oxygen that is a result of plant respiration. Mars, on the other hand, is mostly chemically inert. There is very little metabolism going on there, if there is any at all. Either life there has already eaten up the planet, or else there wasn't enough resource to really get started, or there was never life at all.
Secondly, let's talk about a scenario where life can really only happen with water and organic ( meaning carbon-containing ) compounds. What conditions are necessary for life? What conditions does life thrive in? Take the Earth as an example. Where do we find the greatest mass and biodiversity? In the oceans. Ocean water is practically alive itself, there is so much life in it. On land, the places with the greatest biomass and biodiversity are the rainforests, where they have near 100% humidity. So water as a medium seem to really grow and reproduce. What temperature range do we find the most life in? About 70-90 degrees F -- I'm talking about the *most* life. So the metabolism of life forms seems to function optimally at 70-90 F.
The point I'm trying to make is that yes, we do find life in weird places on Earth -- inside solid rock, in 200 degree sulfuric vents on the ocean floor, inside nuclear reactor cores. However, there isn't very much of it in terms of biomass, and there's not much diversity of forms. My guess is that those 'extremophiles' are descendants of creatures who lived in more hospital environments and became adapted to increasingly extreme environments. I don't think that life originated in rocks or in ocean vents. I think life originated in an environment that is most like where we find the greatest biomass and biodiversity -- water in sunlight at about 60-120 F.
If we're not talking about the above scenarios, we are getting away from materialism, and thus science. This might include "Imagine beings of pure energy" (hey, atoms are 'pure energy') or "What if the sun is conscious?" ( well, we can't measure consciousness *yet* so we can't tell scientifically ) These are fun to think about, but scientifically they are kind of a non-starter.
I understand what you're saying about thinking outside the box, expecting the unexpected, and not limiting our minds or our past experiences. But science puts some serious restraints on what we can imagine or postulate *scientifically*.
It's life Jim (Score:5, Informative)
The three "essential ingredients" for life now seem to be carbon, water and energy but we haven't finished searching the planet yet, let alone our solar system and beyond.
To summerize: "It's life Jim, but not as we know it".
30-year-old news (Score:5, Informative)
You see.... several of the biological experiments on Viking turned up positive. However, this result contradicted other components of the same experiment, which indicated that there were no organic molecules in the soil, among other factors, making the possibility of life existing in those soil samples remotely minute.
It was largely agreed upon that the experiments were inconclusive and poorly designed all the way back in the 80s. The fact that this guy is making this argument about an experiment that yielded a false-positive is somewhat absurd. The bits of the experiment that turned up negative would have hypothetically yielded the same result on a living organism as a dead one.
The ill-fated Beagle 2 [wikipedia.org] probe was supposed to repeat/confirm several of the Viking experiments.
Of course, that's not to say that we shouldn't be reproducing these experiments to figure out what went wrong, and what produced the false positive, as I'm sure there's plenty of interesting science to be explored there as well. I wouldn't completely rule out the possibility of life on mars either -- as mentioned earlier, the experiments were inconclusive.
Re:old video (Score:3, Informative)
Except that life originated in an anaerobic environment: oxygen was not a significant component of Earth's atmosphere for hundreds of millions of years after life began. When oxygen did increase, the atmosphere became inhospitable to those early organisms.
We find a large amount of biodiversity in (now) hospitable environments because of chlorophyl: early plant-like organisms evolved a way to produce energy from sunlight and carbon dioxide. The waste product was oxygen, which still newer organisms were able to utilize through their mitochondria.
Re:I presume they meant silicon-based life... (Score:1, Informative)
Re:It's life Jim (Score:4, Informative)
I first realised the tree was bigger in the early 90's, a documentry explained the lifecycle of slime mold complete with timelapse sequences showing off it's plant, animal and fungal features, but still, that was only four branches in my layman's version of the tree. A few years later I read a book [amazon.com] about how "Alvin" the submersible had expanded the tree with the weird and wonderfull critters that live around deep sea vents and gave a picture similar to figure 1. I've also heard of other branches that extract energy from uranium 2km below ground and still others that live on the cooling rods of nuclear reactors.
Maybe none of this is news to you, but it was to me when I heard it so I thought I would pass it on. Speaking of passing things on, here is an animation [youtube.com] you might enjoy. It's from a group of Havard microboligists showing the workings of a single cell, the animation is set to music so it's up to you if you want to reasearch what is happening. I thought I knew a little bit about cells assembling protiens and such until I saw that video on the news and was awe struck by the sheer complexity of natures nano-machines that have somehow got together and decided to build a pile of temporarily cooperative atoms capable of contemplating it's own navel, (ie: "me").