Scientists from the University of Oxford who compared meteorites originating from Mars and the rocks found today on the Martian surface and studied by Spirit came to this surprising conclusion
The differences in the chemical composition between meteorites that came from Mars and rocks studied by the Mars rover reveal that the fourth planet had an atmosphere rich in oxygen 4 billion years ago - long before the oxidation of Earth's atmosphere about 2.5 billion years ago.
Oxford University scientists have studied the composition of meteorites originating from Mars and reaching Earth, with data from the Mars Rover Spirit who studied the composition of the rocks in the Gusev Crater on Mars.
The fact that the rocks tested on the surface of Mars were richer in nickel than the meteorites was a puzzle and cast doubt on whether the meteorites are a product of Valken on Mars.
"What we have shown is that both the meteorites and the volcanic rocks from the surface, consistently come from a similar source from the interior of the planet Mars. However, the rocks on the surface of Mars formed in an oxygen-rich environment. Apparently the difference is caused by the recycling of oxygen-rich materials into the interior of the planet," says Prof. Bernard Wood from the Department of Earth Sciences at the University of Oxford who led the research published this week in the journal Nature.
The result is surprising because while the meteorites were relatively "young" - only 180 million to 1.4 billion years old, the Spirit vehicle analyzed a very ancient part of Mars - whose traces are over 3.7 billion years old.
It is quite possible that the geological composition on Mars varies from region to region. The researchers believe that it is more likely that the differences appeared along a process known as subduction (a reduction zone - a place where one tectonic plate falls and is pushed under another tectonic plate). In this region, the materials are recycled into the planet's mantle. They hypothesize that the surface of Mars was oxidized early in the planet's history, and that through the reduction, the oxygen-rich materials migrated to a layer just below the surface and resurfaced during eruptions that occurred 4 billion years ago.
In contrast, meteorites are much younger volcanic rocks that came from deep within the planet and were therefore less affected by the process.
Prof. Wood explains: "The conclusion is that Mars had an atmosphere rich in oxygen at the same time 4 billion years ago, long before the increase in the proportion of oxygen in the Earth's atmosphere that occurred 2.5 billion years ago. Since oxygen is what gave Mars its red color, it is also likely that Mars was wet, hot and rusty billions of years before Earth's atmosphere became rich in oxygen."
14 תגובות
And to think I was going to talk to soonmee in person about this.
Eric L.
You did not fully understand the discussion I was referring to. I am referring to the soil on Mars today and the question of why the soil there contains oxidized substances.
The ecology of Mars is not similar to the ecology of Earth, nor is it similar to the ecology of Venus, nor is it similar to the ecology of the moon Titan, nor is it similar to the ecology of the planet Jupiter.... And all and all. Each celestial body has a different ecology, so there is no reason to extrapolate from Earth's ecology to ecologies in other celestial bodies.
Besides, the ecologies of all the heavenly bodies today are not the ecologies they had at the time of their formation (when they were hot with heat or even molten). Therefore, it is not inevitable that the massive oxidation on the soil of Mars took place at the beginning of the formation of the solar system under completely different ecological conditions than there are today (not necessarily from soil oxidation by an atmosphere familiar to us *today*). Therefore, the article you brought is not at all relevant to the question asked about the state of Mars today.
Before I refer further to Mars (if I have the patience to refer to it elsewhere) I have a "riddle" for you regarding the "atmospheric" composition of the Earth *today* at an altitude of 500 kilometers (I wrote "atmosphere" in quotation marks because it is very thin). Here is the riddle:
A. What is the percentage of pure oxygen in the "atmosphere" I mentioned.
B. What causes the composition of the "atmospheric" that I referred to in section a.
If you are too lazy to look for answers here they are:
A. The Earth's "atmosphere" at an altitude of 500 kilometers (which is very thin) consists of 90 percent pure oxygen and 10 percent other substances. When I say "clean oxygen" I mean oxygen that is not chemically related to any substance whatsoever.
B. The presumed cause of the creation of clean oxygen as described in part A, is ecological conditions at high altitude (if I remember, the ecological conditions there are exposure to cosmic radiation and possibly also exposure to ultraviolet solar radiation). Neither photosynthesis nor shoes.
Herzl
Too bad you don't listen to safkan, because you embarrass yourself. The article you referred to is not a scientific theory that should be taken too seriously. First, the article has a lot of assumptions. Moore's Law is not a law - but an observation of the world on a very, very narrow subject. Beyond that, the law is a "self-fulfilling prophecy" - because the law provided goals for development, and appropriate expectations.
The authors themselves also write that it is a "mental exercise".
safkan, as far as I understand, is also right about the inventions of free oxygen. We know, for example, that there is free oxygen in Saturn, without any need for life. The conditions for oxygen inventions are unusual, but certainly not unreasonable.
But - the presence of free oxygen definitely implies that there is, or was, life of the kind we know. It's part of James Lovelock's "Gaia" theory and it's not stupid at all.
You don't have to worry too much. Under the entry oxygen, the subject of free oxygen is explained quite clearly:
"Oxygen is too chemically reactive to remain a free element in Earth's atmosphere without being continuously replenished by the photosynthetic action of living organisms, which use the energy of sunlight to produce elemental oxygen from water. Free elemental O
2 only began to accumulate in the atmosphere about 2.5 billion years ago (see Great oxygenation event) about a billion years after the first appearance of these organisms.”
https://en.wikipedia.org/wiki/Oxygen
Herzl
You continue to insist and hold wrong opinions. The fact that you raise your voice does not make your words true. Your mistaken opinion is that the oxidation of substances is possible only when there is oxygen in the atmosphere in a considerable amount and this is only possible in photosynthesis processes.
Oxidation-reduction processes are also possible in the absence of free oxygen in the atmosphere in considerable quantities, also certain conditions allow the release of oxygen into the atmosphere without photosynthesis processes, if you are not aware of this, your knowledge of chemistry is probably not worth much. The whole science of chemistry is based on the fact that bonds between elements in a molecule are not eternal bonds, bonds which may be allowed under certain conditions and then the atoms in the molecule can become free or bind in other molecular bonds (and create new compounds). This rule applies in particular to oxygen atoms when it is in a compound.
As for your lack of seriousness in general. Evidence of this is your reference to an article about the formation of life 9 billion years ago. It's just a model that is based on *certain assumptions* that cannot be proven or disproved, as soon as you claim that this article is a *safe* source for describing reality, you prove yourself to be shallow. In my estimation, the assumptions on which the above article is based are not agreed upon by most researchers, and even more so are not *safe* as you present it.
To the skeptic - sorry, but there is a basic knowledge gap in chemistry that cannot be bridged in a few sentences. Either you accept that pure oxygen is not possible without life, or you don't. Or study some chemistry - a high school level is enough.
Herzl
I think you are just insisting. Where did the oxygen that was needed to create co2 and create h2o come from? After all, most of them were created at the dawn of the universe before the creation of life. There is probably oxygen available in the universe regardless of the reality of life and photosynthesis.
Available oxygen does not have to be pure oxygen. There are chemical processes in which elements that are loosely bound to each other change, the change is such that some of the aforementioned elements move to another, more stable compound. Such a transition is in principle possible for oxygen.
The oxygen atoms exist, but oxygen by itself is so reactive that it immediately combines with carbon, hydrogen, iron, etc. Only biological processes release oxygen and in order for there to be oxygen in the atmosphere, the biological processes need to continue for a long time.
Dan
Oxygen also comes from non-biological sources, otherwise where did co2 and h2o come from?
To Dan - exactly. What was not said in the article, but is obvious, is that oxygen in the atmosphere can only be of biological origin. Connects nicely with this article:
http://phys.org/news/2013-04-law-life-began-earth.html
Which shows that life probably started 8-9 billion years ago and spread between star systems in the galaxy.
Ooops or not 😛
typo
"Shahtavaim" should mean that the conditions.
End of third paragraph
Wait, but oxygen arises only as a result of a relatively evolutionary advanced biological activity of photosynthesis? And enough oxygen to oxidize all the iron suggests the existence of a huge biomass for a geological time period.
What is not clear to you? We even saw it in the movie Fatal Memory that there is a lot of oxygen underground