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Nasa call a news conference concerning an astrobiology finding that will impact the search for evidence of extraterrestrial life.

http://www.nasa.gov/home/hqnews/2010/no ... ology.html

I hope I'm not let down by the potential exciting nature of this.

I have a feeling that unless during the conference one of the speakers rips off their face and proclaims 'I am Tp'xluu, ambassador to the intergalactic alliance.' Your going to feel let down.

It's most likely going to be 'There is a mathematical possibility that some form of life might exist on this distant planet, we need more money.' Or 'There is strong evidence to suggest that at one time there might have been some form of life on this planet we've already visited. We need more money.'

The first thought that came to mind when I read this post and scanned the release was that we were about to be introduced to our new alien overlords.

Nice knowing you all, I'm guessing there's a chance they'll shut down the internet so we can't organise against them so easily.

Failing that most likely scenario, I think Jean's "we need more money" is about right.

They've found bacteria living in arsenic-rich, phosphorous-free environment. Life existing without phosphorous means that there are potentially a lot more places to look for life in the cosmos.

Tomo wrote:They've found bacteria living in arsenic-rich, phosphorous-free environment. Life existing without phosphorous means that there are potentially a lot more places to look for life in the cosmos.

...And therefore this explains why they require additional funding.....

But they knew life could exist like that anyway... only have to look at sulphur pools at the bottom of the ocean and how there is a lot of rich life around those vents etc....

Jordan C wrote:But they knew life could exist like that anyway... only have to look at sulphur pools at the bottom of the ocean and how there is a lot of rich life around those vents etc....

Not quite. Rather than just being extremophilic, this bacteria doesn't use phosphorous in its DNA.

But what always puzzles me from the scientists is there insistence on conditions similar to ours for there to be life, when that may not need to be the case.

They may need totally different conditions.

midge25 wrote:But what always puzzles me from the scientists is there insistence on conditions similar to ours for there to be life, when that may not need to be the case.

They may need totally different conditions.

Indeed. In science, being proven wrong in this way is very exciting when it reveals something new to explore.

The important thing is that it shows that life has started at least twice on earth. And that there is prolly more life candidate planets out there.

Ian

I've not watched the whole thing yet, but as far as I can tell there's no suggestion that life started twice.
They took a microbe from a very hostile environment, deprived it of phosphorous and it substituted available arsenic instead.

It really doesn't seem like they are talking about something that doesnt/didn't use phosphorous, but rather something that is capable of using arsenic instead of phosphorous.

Not quite the same.

I'm happy to be corrected on this, but while undeniably groundbreaking I don't see the hugeness some seem to. Surely this is an example of adaptation, not of unique origin.

Not really - its DNA has no phospherous. Not that it survives without it, it appears that it didn't have any to start with.

If you read some of the news covering this from yesterday, the NASA people were talking about a second start of life - one that started in an environment without phospherous.

I've been watching the conference and going on what the leader of the team that made the discovery/experiment said in it.
She repeatedly uses the word "substitution" thourghout her speech and in the Q&A.

There is phospherous in the lake bed they got the bacteria from to create the cultures they experimented on.

From a Nasa article on the issue...
"The newly discovered microbe, strain GFAJ-1, is a member of a common group of bacteria, the Gammaproteobacteria. In the laboratory, the researchers successfully grew microbes from the lake on a diet that was very lean on phosphorus, but included generous helpings of arsenic. When researchers removed the phosphorus and replaced it with arsenic the microbes continued to grow. Subsequent analyses indicated that the arsenic was being used to produce the building blocks of new GFAJ-1 cells.

The key issue the researchers investigated was when the microbe was grown on arsenic did the arsenic actually became incorporated into the organisms' vital biochemical machinery, such as DNA, proteins and the cell membranes. A variety of sophisticated laboratory techniques was used to determine where the arsenic was incorporated."

That it's part of a common group and that they were investigating effects of a zero phosphorous, high arsenic diet on the microbe suggest that it wasn't a seperately started life, but actually an adaptation of an existing strain. I can't quite figure out whether the arsenic was incorporated pre-laboratory or not though.


As for the news coverage of this... I'm paying them little heed because this is an absolutely perfect topic for sensationalism.

"There is absolutely some phosphorous left in these cells."
From the team leader, during the conference.