Earlier quoted context omitted.
3/4 billion = 750 million, no?
Long billion vs short billion?
Didn’t the “long billion”, aka a trillion, stop being used sometime in the early 20th century on British English, if not earlier?
New findings point to an Earth-like environment on ancient Mars
91–100 of 329 posts
Re: New findings point to an Earth-like environment on ancient Mars
#92Earlier quoted context omitted.
Mars had 3/4 billion more years to develop, compared with the Earth. Mars formed first, and cooled first due to its smaller size. One of the outstanding problems in astrobiology I mention is that the Earth was inhospitable until 3.8Gya, and the oldest fossils of presumably DNA based life (since it matches existing life we can study) was 3.7Gya. Mars was hospitable ~4.5Gya. So either life emerged IMMEDIATELY on Earth…
At this point, given how much Mars had been roved, why hasn’t some fossil record been discovered yet? At the very least, I would expect something akin to chalk left behind by proto-diatoms that had calcium carbonate skeletons.
I think there have been less than 100 drill holes by curiosity and perseverance the deepest being ~3” and none of those samples have returned to earth. Not sure how deep any potential fossil layers might be but that doesn’t sound like a lot.
Re: New findings point to an Earth-like environment on ancient Mars
#93yay, likelihood that we are martians just went up a few basis points
It seems very low likelihood that a life-bearing chunk of Mars arrived and seeded life here. What are the chances that some type of single-cell critter(s) from Mars were robust enough to: 1) Survive the trip here with the extreme cold of space, AND 2) Survive the searing heat of entering earth's atmosphere, AND 3) Survive conditions on earth, when they were adapted to the martian environment And that's all premised o…
Curious why there is much less interest in the Pleiades, which is made of all of our same material and is very likely a "fork" of earth formed after the original mass that later became earth and moon colliding with another body in early history.
Re: New findings point to an Earth-like environment on ancient Mars
#94One thing that has annoyed me is in the 1970s the Viking landers did experiments to check for the presence of life on Mars known as the Labeled Release experiments https://en.wikipedia.org/wiki/Viking_lander_biological_exper... which dropped a nutrient solution with radioactive Carbon-14 to detect if there was any off gassing to detect if anything metabolized the soil. And both experiments showed positive results but…
> But what puzzles me is why we have never followed up with any further experiments to try and detect life? After the Viking missions we never conducted any further experiments that could rule out any other possible chemical reactions to get closer to confirming the presence of microbial life. According to Wikipedia, the radiation levels are too high: https://en.wikipedia.org/wiki/Life_on_Mars#Cosmic_radiation > Even…
People have said the same thing many times yet we keep discovering extremophiles thriving the some of the most hostile environments. And in 2020 they conducted an experiment on the ISS that exposed Earth bacteria to direct cosmic radiation for 3 years and it turns out they survived https://www.smithsonianmag.com/science-nature/scientists-dis.... And this was just Earth bacteria that did not evolve under these conditions, any remaining microbes on Mars would have developed adaptions to survive in such conditions.
Re: New findings point to an Earth-like environment on ancient Mars
#95Kurd Lasswitz wrote "Two Planets" in 1897, https://news.ycombinator.com/item?id=39598983 > Lasswitz's Martians differ little from man physically, but ethically, intellectually, scientifically, and socially they are the prototype of the ideal human being. They seek to educate man, asking in return only air and energy to supplement the diminished supplies in their own, older world. The story revolves around a group of…
Possibly worth also including just how controversial Wernher von Braun is. Von Braun is a highly controversial figure widely seen as escaping justice for his Nazi war crimes due to the Americans' desire to beat the Soviets in the Cold War https://en.wikipedia.org/wiki/Wernher_von_Braun
What does that have to do with the comment you're replying to?
Edit: This is an honest question, I'm not familiar with the extent of his crimes, if any. It certainly doesn't seem like a clear-cut "he was an objectively evil man but we looked the other way" based on the Wikipedia article. It could very well be his account, which from a brief skim seems reasonable, is accurate?
Re: New findings point to an Earth-like environment on ancient Mars
#96Why don’t we just drill into mars and look for fossils? Easy peasy.
I don't remember where I read it, but somebody wrote that a geologist with a hammer could do more science in an afternoon than all our mars probes have done combined. Its hard to do science with a rc car, even if said car is cutting edge.
Humans can also take on new research objectives on the fly while rovers/probes can only ever do what they were designed to. The difference in flexibility, capability, and speed are vast.
Re: New findings point to an Earth-like environment on ancient Mars
#97Re: New findings point to an Earth-like environment on ancient Mars
#98Earlier quoted context omitted.
Mars had 3/4 billion more years to develop, compared with the Earth. Mars formed first, and cooled first due to its smaller size. One of the outstanding problems in astrobiology I mention is that the Earth was inhospitable until 3.8Gya, and the oldest fossils of presumably DNA based life (since it matches existing life we can study) was 3.7Gya. Mars was hospitable ~4.5Gya. So either life emerged IMMEDIATELY on Earth…
At this point, given how much Mars had been roved, why hasn’t some fossil record been discovered yet? At the very least, I would expect something akin to chalk left behind by proto-diatoms that had calcium carbonate skeletons.
There's been less than 150 miles of Mars roamed by mostly small rovers that often could barely do more than take pictures and do some basic soil chemical analysis. Do you expect to see obvious dinosaur remains with an RC car with a small shovel driving around in Kansas for 100 miles, especially if you don't even know what a dino even looks like?
Re: New findings point to an Earth-like environment on ancient Mars
#99Earlier quoted context omitted.
Mars had 3/4 billion more years to develop, compared with the Earth. Mars formed first, and cooled first due to its smaller size. One of the outstanding problems in astrobiology I mention is that the Earth was inhospitable until 3.8Gya, and the oldest fossils of presumably DNA based life (since it matches existing life we can study) was 3.7Gya. Mars was hospitable ~4.5Gya. So either life emerged IMMEDIATELY on Earth…
At this point, given how much Mars had been roved, why hasn’t some fossil record been discovered yet? At the very least, I would expect something akin to chalk left behind by proto-diatoms that had calcium carbonate skeletons.
> At this point, given how much Mars had been roved
I mean maybe its a lot compared to 20 years ago but in absolute terms? It’s practically nothing, isnt it?
Re: New findings point to an Earth-like environment on ancient Mars
#100Earlier quoted context omitted.
Your numbers give Mars an extra ~800 million years. Nothing even close to 3/4 billion. Besides, deciding what was inhospitable for early life is an exercise of noisy assumptions. I'd bet the error margin is larger than that difference.
3/4, as in the fraction 3 out of 4, 75%, not 3-4
To be fair, 3/4 billion is an unusual way to write that. Much more common is 750 million, or even 0.75 billion.