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A newly discovered exoplanet may support life ... but don't pack your bags yet

20 light years from Earth slumbers the red dwarf star Gliese 581.  Today a team of astronomers announced an astonishing discovery-- the star has a planet which is potentially habitable by humanity.

Over 200 so-called "exoplanets" -- planets outside our own solar system -- have already been found.  But so far, all of them have suffered from the "goldilocks problem," either too hot, too cold, or far too massive to support life.

But the new planet, which so far is only being called "c," is different.  It has an atmosphere, liquid water, a surface temperature estimated to range from 32 to 104 degrees Fahrenheit.  It is roughly five times as massive as the earth but, due to a larger diameter, has a surface gravity only1.6 times that the Earth's.   It's also much closer to its parent star, having a 'year' only 13 days long.  The view from the surface would be spectacular, with the planet's sun appearing in the sky some 20 times larger than does our moon.

"On the treasure map of the Universe, one would be tempted to mark this planet with an X", says report co-author Xavier Delfosse of Grenoble University. "Liquid water is critical to life as we know it.  Because of its temperature and relative proximity, this planet will most probably be a very important target of future space missions dedicated to the search for extraterrestrial life."

The team examined 100 different stars using the HARPS planet searcher at the European Southern Observatory in the Chilean Alps.



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By geddarkstorm on 4/25/2007 3:14:00 PM , Rating: 2
This planet orbits a red dwarf star so close that it only has a year of thirteen days and is fourteen times closer to its star than we are? Red dwarfs have many practical problems for habitability of any plants in the habital zone. For instance, most of the energy of a red dwarf is given off in the infrared, unlike our star which gives off in the visible. This would make it impossible for photosynthesis to proceed as infrared is far too low a wavelength.

Secondly, its known that red dwarfs can lose up to 40% of their brightness, or double their brightness in a massive solar flare due to sunspots. One blast of that beast and any life on a planet will be totally cooked; or one long period of sunspot activity and the planet is a frozen ice ball.

Thirdly, being that close to a star puts you very much so in the way of intense radiation, high level magnetic and solar winds, and could potential lock a planet's tidal system and day/night system so that one side is light while the other is dark, but causing massive temperature variations and instabilities all across the planet.

I really doubt a red dwarf planet could be suitable for life let alone human colonies.




By cochy on 4/25/2007 3:38:35 PM , Rating: 2
quote:
This would make it impossible for photosynthesis to proceed as infrared is far too low a wavelength.


Life develops its mechanisms for survival based upon it's surrounding ecosystems. Life evolves to adapt. Obviously plants here on Earth would make use of the abundant sunlight from the Sun to make energy. Why would you assume life some place else would need the same process? It obviously wouldn't. It would adapt to survive in it's unique ecosystem.


By geddarkstorm on 4/25/2007 7:08:44 PM , Rating: 2
I said photosynthesis would be impossible, not all forms of life. As, you need to know quantum mechanics, but infrared wavelenths are too long to interact with electrons, which absolutely necessary for electronic energy generation which is what photosynthesis is. Infrared interacts with the nucleii of atoms and affects such things as bond vibrations. stretches, and bends; but it does not effect electrons.

No matter how resilient people may have this misconception that life is, life is bound by the laws of nature--physics (including kinetics), and chemistry (thermal dynamics)--just the same. There are limits to all things.


By masher2 (blog) on 4/25/2007 9:28:02 PM , Rating: 3
This just isn't true, sorry. There are bacteria on earth that perform photosynthesis in the infrared spectrum, such as the Chloroflexi or some of the Rhodopseudomonas. All you need is enough energy to excite an electron to a higher orbital...you don't ionizing radiation.


By novacthall on 4/25/2007 5:03:39 PM , Rating: 2
At the bottom of the ocean on our own planet, in pitch black, at temperatures that border on freezing and boiling near geothermal vents, life is not only present, it's abundant.

Life is extremely resilient; don't be so quick to count it out.


By geddarkstorm on 4/25/2007 7:19:57 PM , Rating: 2
That is assuming that this planet has a rocky, molten core like our own and that it has liquid oceans covering over geothermal vents; notwithstanding the fact that the molecular basis for life formation is totally unproven and mysterious but having it happen at a geothermal vent is impossible due to the labial nature of RNA, DNA and proteins at high temperatures (let alone all the reducing agents like H2S and other acids/heavy metals that are common at such vents which rapidly destroy organic molecules that lack sophisticated enzymes to protect them). Hydrothermal vent living creatures on our own planet are creatures that appear elsewhere (before hand) which then adapt to hydrothermal vent life; and it is quite a difficult thing too.

However, this planet is unknown if it has a rocky, molten core; but given that its star, being a red dwarf, is very poor in heavy metals (a consequence of its slower and less efficient fusion, along with small size. Only larger, hotter stars can fuse hydrogen into metals, such as our own can do), it is unlikely that the same stellar dust that gave rise to that type of star could have given rise to a molten, rocky cored planet. Not impossible, but highly unlikely. And even then; without a deep sea, or highly thick atmosphere, or deep subteranean pockets (where life does not form in our planet; life has to get there then adapt, just like with hydrothermal vents), one solar flare and that planet will be gamma ray backed (if it isn't already just by being so close to a star).

Life is bound by the laws of nature, resilience is simply part of its complexity, but you have to get to that complexity first. Life is, however, also extremely fragile. It's not impossible (that is if it's possible for life to arise from planetary prebiotics anyways, and what prebiotics it would be possible to arise from are an aboslutely mystery), but extraordinarily unlikely in such a star system. But hey, weirder things have happened.


By RMTimeKill on 5/23/2007 2:58:52 PM , Rating: 2
This is all based on what we know about our planet and local solar system, which could be totally proven wrong in another solar system. Its like saying, yea, my Detroit Muscle V8 thunder is the only way to give life to my car, there is no other way! Then a Prius passes you... We know next to nothing of how life works, these laws and boundries you speak of are things set by men due to examples they have seen. There are still 1000s of life forms on our own planet we havent discovered so to claim these laws are absolute is absolutely asinine...


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