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New Evidence For Ancient Life On Mars
siddesu writes in with "compelling" new data that chemical and fossil evidence of ancient microbial life on Mars was carried to Earth in a Martian meteorite. The finding is being highlighted by the same NASA team who made the initial discovery 13 years ago. Spaceflight Now has more details of the analysis.
I'm rooting for independent evolution. It would make it far more likely that the universe is teaming with life. But unless we find current life on Mars, it may be hard to tell the difference.
Can someone explain to me why the set of meteorites are considered more likely to have originated on Mars than from an impact on Earth itself?
Are there Earth-origin ones known to distinguish them from, since debris from such an earth impact would more likely have orbits intersecting earth's, or is some other evidence used? I'm having trouble finding it.
Got to actually read the articles. They explain the traces of atmosphere match Mars not the Earth. A number of other Mars meteors have been identified. The article even mentions two others with the same structures. Lots of good info if you read the articles. Once people throw in the towel and accept that there was or is life on Mars then the argument will be did it evolve there and is it part of the same evolutionary cycle as Earth? Those are the fights that will likely take decades and there may never be a clear answer. It's a massive question because if it did evolve independently then anywhere life could evolve it probably has evolved meaning there are millions of planets with life just in our Galaxy. I think within the next 20 years there will be a resolution to the question of life based on direct sampling but the second question of it's source will be a fight to the bitter end.
Either case means the same thing, that life can travel and spread. It takes millions of years for a rock from mars to reach earth, and vice versa. If life can survive that journey, why couldn't it survive in some small way between stars, over billions of years.
If life once existed on Mars, it will exist now. It is highly unlikely the entire planet became 100% sterile. There will be pockets of life surviving the harsh climate.
The big question is exploration of Mars. If life evolved independently, we will have a much harder time mucking around there, especially colonizing it. Folks will want to leave it alone to its own devices. It life on Mars and life on Earth share a common history, it makes it much easier to muck around on Mars, because it'll just be another extension of life here so no worry about contamination.
If it wasn't for the spacecrafts sent to Mars, it would not have been possible to identify the meteorite as coming from Mars. From the article : "Scientists were able to trace the meteorite back to Mars, as its chemical composition matched the relative proportions of various gases measured in observations of the atmosphere of Mars made by the Viking spacecraft in the 1970s."
As for the rovers sent later, they were not sent to investigate life but mainly to study the geology and climate.
Either case means the same thing, that life can travel and spread
No, they don't mean the same thing. If life began once and was seeded via meteorites, then it's a giant crap-shoot, and the vast majority of solar-systems are probably sterile. On the other hand, if abiogenesis took place twice in a single solar system, then the universe is probably teeming with life.
If life evolved independently, we will have a much harder time mucking around there, especially colonizing it. Folks will want to leave it alone to its own devices.
Hardly. It might raise some ethical conundrums, but it certainly won't make colonization any more difficult.
If we ever colonize mars, we're going to start by building habitats. We'll have hundreds of years to live on a planet which we haven't even begun to terraform. That will give us plenty of time to have the People for the Ethical Treatment of Martian Lifeforms present a convincing case for why we should abandon an entire planet to a bunch of alien microbes. If they fail in convincing the rest of humanity, then we'll carry on with our terraforming effort, and the Martian bacteria will be relegated to sample jars, museums, and computer databases.
Mars-to-Earth is 100% because we found a dozen or so meteorites from Mars, proving it happens. (Kudos to Viking Landers for the chem analysis to compare.)
Because of Earth's size compared to Mars, Earth was still a hot coal when Mars was almost like Earth today, with mild temperatures, relatively thick atmosphere, and lakes, possibly even oceans. Thus, life is more likely to have had evolved on Mars early in the solar system's history than Earth, if it was around then. Mars was the happening club in town back in the days.
Table-ized A.I.