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NASA Has Found Extraterrestrial Life (pg. 5)
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| Sushipunk |
| quote: | Originally posted by The17sss
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:wtf: |
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| djsaekone |
| mars moon...phobos...monolith |
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| Lira |
| quote: | Originally posted by MrJiveBoJingles
I don't think religious ideas about human "specialness" are conclusions derived from facts about our biochemistry. :p |
Indeed, I can hear religious groups claiming that we're more special than these bacteria because we are rational moral beings, and they're underdeveloped at best. Not to mention the denialists, because <some divinity> said somewhere we're special so these are just lies propagated by science and <poorly designed argument>. |
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| Vivid Boy |
| MAAAAAAAAn, this was a bull announcement. Bacteria can live in arsenic on earth???this aint in space news this is WWF news. what next Nasa going to start commenting and holding press conferences on Bradgelina?? |
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| Moongoose |
| quote: | Originally posted by tubularbills
Nonono, i'm not talking about the farthest point and the shortest point (forget the names of those particular points)....but if it were some distance further or closer at those particular spots. Earth really is an amazing balance of numerous astronomical phenoms for us to exist here. (at least, in the current form). if we were further, we'd probably have alligator-like skin to keep us warm....or if we were closer, we'd all be living in modern-day australia. |
Aphelion and perihelion :D And sure, if earth were farther or closer to the sun it would have been very different, but it would take much more than a few 100 miles for any significant changes. Add about 24 million kilometres to the earth orbit (1/3 of the way to Mars) and living in Australia might actually be a pleasant experience (theres still all the creepy bugh though...) |
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| Renegade |
It's pretty exciting news, but I think it's suffered from all the build-up.
Basically what we can take from this is how flexible life is in adapting to a range of conditions that we previously thought would make life impossible. Sadly this is not a new or "different" form of life (it's simply bacteria that's adapted itself to the presence arsenic) and it doesn't use arsenic in its DNA (as was originally reported - now that would be a ing big deal) but it shows us that the chemcical conditions under which life can emerge and thrive are more flexible than we assumed. The implication is that the earliest forms of life on this planet needn't have been chemically identical to present forms of life, as apparently some chemicals (in this case phosphorous and arsenic) can be subsituted in at least some organic processes. This might have some major implications for hyphotheses concerning how life on this planet first emerged.
As for life elsewhere, meh. Even if this is direct evidence for the fact that arsenic can be involved in the kind of complex reactions necessary for life (and make the inference that maybe therefore silicone can be substituted for carbon etc.) I'm not really sure it's going to change what we're looking for. Phosphorous and carbon are still much more common in the universe than arsenic and silicone, and due to their smaller size are still probably much more likely to be present in the kind of complex chemistry involved in the processes necessary for life. If we're talking about findings that are exciting in the context of astrobiology, then I think there have been other findings - such as the capacity of RNA to self-replicate and "evolve" under changing conditions - that have been much more important than this. |
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| Renegade |
| quote: | Originally posted by tubularbills
Nonono, i'm not talking about the farthest point and the shortest point (forget the names of those particular points)....but if it were some distance further or closer at those particular spots. Earth really is an amazing balance of numerous astronomical phenoms for us to exist here. (at least, in the current form). if we were further, we'd probably have alligator-like skin to keep us warm....or if we were closer, we'd all be living in modern-day australia. |
Well obviously for life to exist in its current form the Earth has to exist within a pretty narrow orbital path around the sun, but the "Goldilocks Zone" (the zone in which liquid water - and therefore life - is possible) is much wider than that, and dependent on many more criteria than just distance from the sun.
For instance we say that Mars is well outside of the Goldilocks Zone, but it was apparently warm enough to sustain oceans billions of years ago. If Mars was bigger - and therefore capable of retaining a thicker atmosphere - it may have been warm enough to retain liquid oceans to this very day. By contrast, the Earth was very nearly completely frozen over 700 million years ago (see "Snowball Earth") and were it not for geothermal processes (and Earth is one of the very few bodies in the solar system to remain geologically active!) then a negative feedback loop - where all the sunlight would have been reflected by the ice back into space, keeping the temperature on Earth below freezing - might have seen the Earth completely and irreversibly frozen over.
In other words, the fact that Earth is suited to life and Mars is not has almost as much to do with the relative size of the planets and the processes going on at their centre as it does with their positions relative to the sun. |
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| Omega_Blue |
Meh. Didn't scientists discover some sort of marine species that lives near underwater volcanic emissions that uses like, sulfur in their energy synthesis? I think they called it chemiosynthesis or something like that? How is this any different?
So much hype over old news, imo. |
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| woscar |
| It's different because the bacteria is thought to incorporate arsenic into it's biochemistry. |
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| Trance-MB |
| LOL at Area51 they have spaceships so why bother for something that tiny.......? ;) |
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| The17sss |
heartache regarding the whole "extraterrestrial" thing:
| quote: | As soon Redfield started to read the paper, she was shocked. “I was outraged at how bad the science was,” she told me.
Redfield blogged a scathing attack on Saturday. Over the weekend, a few other scientists took to the Internet as well. Was this merely a case of a few isolated cranks? To find out, I reached out to a dozen experts on Monday. Almost unanimously, they think the NASA scientists have failed to make their case. “It would be really cool if such a bug existed,” said San Diego State University’s Forest Rohwer, a microbiologist who looks for new species of bacteria and viruses in coral reefs. But, he added, “none of the arguments are very convincing on their own.” That was about as positive as the critics could get. “This paper should not have been published,” said Shelley Copley of the University of Colorado.
In fact, says Harvard microbiologist Alex Bradley, the NASA scientists unknowingly demonstrated the flaws in their own experiment. They immersed the DNA in water as they analyzed it, he points out. Arsenic compounds fall apart quickly in water, so if it really was in the microbe’s genes, it should have broken into fragments, Bradley wrote Sunday in a guest post on the blog We, Beasties. But the DNA remained in large chunks—presumably because it was made of durable phosphate. Bradley got his Ph.D. under MIT professor Roger Summons, a professor at MIT who co-authored the 2007 weird-life report. Summons backs his former student’s critique.
But how could the bacteria be using phosphate when they weren’t getting any in the lab? That was the point of the experiment, after all. It turns out the NASA scientists were feeding the bacteria salts which they freely admit were contaminated with a tiny amount of phosphate. It’s possible, the critics argue, that the bacteria eked out a living on that scarce supply. As Bradley notes, the Sargasso Sea supports plenty of microbes while containing 300 times less phosphate than was present in the lab cultures. |
http://www.slate.com/id/2276919/pagenum/all/ |
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