Thread: Gliese 581

With another small planets in a five planet system just 20 light years away this is turning into one fascinated place.

"Well-known exoplanet researcher Michel Mayor today announced the discovery of the lightest exoplanet found so far. The planet, “e”, in the famous system Gliese 581, is only about twice the mass of our Earth. The team also refined the orbit of the planet Gliese 581 d, first discovered in 2007, placing it well within the habitable zone, where liquid water oceans could exist. These amazing discoveries are the outcome of more than four years of observations using the most successful low-mass-exoplanet hunter in the world, the HARPS spectrograph attached to the 3.6-metre ESO telescope at La Silla, Chile."
http://www.eso.org/public/outreach/p.../pr-15-09.html

Being part of a red dwarf what else would we expect or look for as a sign for possible life:
-expect a gravitationally locked world, with at atmospheric circulation much different than ours?
-search for types of photosynthesis that optimized for lower energy such as that underwater life here, and of different reflective colors than our green planets?
What else?

def is interesting. I hope sometime in my lifetime we figure out other species that exist in the universe. It will be interesting to see how they differ from what we have on earth.

This is a link to an article in Astronomy magazine that describes how none of the believed chemical precursors to life seem to exist around red dwarf stars (M-dwarf stars):
http://www.astronomy.com/asy/default.aspx?c=a&id=8093
If the star has no chemical precursors to life in its planetary disk, then planets around these stars may have no life (no chickens if no eggs). These “cooler” M-dwarfs apparently don’t get the necessary chemistry going to create hydrogen cyanide. So an ocean on an Earth sized planet in the habitable zone around such a star with no hydrogen cyanide molecules would be a lifeless pool. As 70% of the stars in the Milky Way are M-dwarfs, this is not good news for SETI, unless life on such a planet is radically different from what we know works.

Surprising.

Too bad we don't know more about abiogenesis. Only finding life on other worlds will lead us to a better understanding.

Originally Posted by Arch2008

This is a link to an article in Astronomy magazine that describes how none of the believed chemical precursors to life seem to exist around red dwarf stars (M-dwarf stars):
http://www.astronomy.com/asy/default.aspx?c=a&id=8093
If the star has no chemical precursors to life in its planetary disk, then planets around these stars may have no life (no chickens if no eggs). These “cooler” M-dwarfs apparently don’t get the necessary chemistry going to create hydrogen cyanide. So an ocean on an Earth sized planet in the habitable zone around such a star with no hydrogen cyanide molecules would be a lifeless pool. As 70% of the stars in the Milky Way are M-dwarfs, this is not good news for SETI, unless life on such a planet is radically different from what we know works.

The discovery of extremophiles has pushed our understanding of how life can not only survive, but thrive in extremely hostile conditions. I think it is a naivety of science to believe that the precursors to life can only exist on other worlds in relation to the way they exist here. I do not place faith in that report, and it is more likely that life in the universe is not a chance coincidence, but rather a universal inevitability. We have far too much to learn before we can make assumptions about the way life "should" evolve in other systems. Again, surprising and unexpected discoveries on our own planet should be a testament to this. Unfortunately, with nothing other than Terran organisms to reference in this capacity, we will have to await the discovery of "off world" organisms to conclusively substantiate this debate, pending of course we can recognize them :wink:.

We have to be careful we don't end up with tunnel vision, looking for life only as we know it. Extremeophiles can take a vacuum, live in boiling acid (upto pH2) as well as strong alkalies, live miles underground or under water, live in water next to 400.C volcanic vents, survive radiation, lay dormant for eons (when things are bad), live in toxins and so on. Who is to say that one strain given enough time might not evolve in what we call a hostile environment? After all oxygen is quite hostile to some.

Well said, Cyberia. I couldn't agree more

This may be a major drawback in our search for life on Mars. We utilize equipment to detect life as we know it based on the similar chemical reactions that would be expected of Terran micro-organisms . Will we actually recognize life on Mars should it prove to exist? I suppose it's akin to reading a book before you've learned the alphabet.

Electrically charged specks of interstellar dust organize into DNA-like double helixes and display properties normally attributed to living systems, such as evolving and reproducing, new computer simulations show.

But scientists are hesitant to call the dancing dust particles "alive," and instead say they are just another example of how difficult it is to define life.

The computer model, detailed in the Aug. 14 issue of the New Journal of Physics, shows what happens to microscopic dust particles when they are injected into plasma.


http://www.msnbc.msn.com/id/20264620/?GT1=10252



Some decades back, Fred Hoyle wrote a story called "The Black Cloud" about a massive cloud in space that was not just self aware but super-intelligent. While a living cloud might be possible, distances would be so great that it would live on a far slower time scale than us so maybe a year to us would only be an hour to such an organism. I think it would likely only have very basic intelligence rather than super-intelligence. Possibly some kind of "hive-mind".

I agree that the search for life is restricted to our common understanding of what life is. As a consequence, all those searches include the presence of water as a prerequisite. But such a view might indeed be flawed. However, how else can we define "life"? What is life anyway? Would we be able to recognise it, if it came in different shapes than we could think of? What else should we look for?

The "Black Cloud" story is a nice example. A similar story was written by my all time favourite sci-fi author Stanislaw Lem called "The Invincible".

It is a problem that if we are looking for non-Earth type life, we must have a clue as to what it is and what environment it would best survive in

http://books.nap.edu/catalog.php?record_id=11919#toc

Not a problem without a solution.

Originally Posted by Arch2008

http://books.nap.edu/catalog.php?record_id=11919#toc

Not a problem without a solution.

Thanks for the hint! I am tempted to buy it. But maybe it would be something for our institutes's library. Then I'd get it for free.

"While a living cloud might be possible, distances would be so great that it would live on a far slower time scale than us so maybe a year to us would only be an hour to such an organism. I think it would likely only have very basic intelligence rather than super-intelligence. Possibly some kind of "hive-mind"."

Well, as a whole it would be relatively huge, and thus time would be relatively slow, but if it was a hive mind of sorts, any part of the whole might be incredibly fast, like a computer. Less adaptable than our own brains, but also more in control of it's physical form.

What could such a being be capable of? Could it use electromagnetism to incite motion within the cloud, which then makes gravitational changes, as a means to change it's shape and density? What about motion? Is there any way such a being could propel itself through space and change directions without the use of external forces? Or would it have to learn to harness these forces?

What would motivate it? Food? The acquisition of more substance to add to it's form? Would it be strengthened by heat/companionship or would it be better of alone? LOL, this is very interesting to ponder.

Cyberia Wrote: "Electrically charged specks of interstellar dust organize into DNA-like double helixes and display properties normally attributed to living systems, such as evolving and reproducing, new computer simulations show."

Interesting simulation, absolute! Thank you for the share on that, Cyberia.

Excellent reference, Arch2008. Thank you. Enlightening, indeed.

Hahaha...yes Dishmaster, what IS life anyways? Here I 'live', and yet do not know entirely what defines the concept of 'life' itself. What an irony!

marcusclayman Wrote: "Well, as a whole it would be relatively huge, and thus time would be relatively slow, but if it was a hive mind of sorts, any part of the whole might be incredibly fast, like a computer. Less adaptable than our own brains, but also more in control of it's physical form."

Aw, good 'ol relativity. What is relativity anyways? As an individual organism, my concept may differ from one others perspective. So how exactly is relativity defined (philosophically, not mathematically speaking)? Though this is not actually a serious question, it might be interesting to read everyone's thought on this matter. Perhaps another thread may be needed? What do you guys think?

Has it ever occurred to anyone that galactic super structures look an awful lot like the helix of DNA (or is it just me?)? Food for thought - I'll let you're imagination run wild with that, as it has for my own (and it does keep me awake at night, from time to time)

Obviously, with so many galaxies, stars within, planets within...one can only speculate as to the possibilities. Or am I completely insane???