"Goldilocks" Planet can sustain life.

[Doc. Josh]

As per article http://news.discovery.com/space/earth-like-planet-life.html If this has been discoverd then why would we presume any further that life does not exist off our planet? And to the same accord is it feisable to inhabit such planet someday?

[mooeypoo]

As per article http://news.discover...lanet-life.html If this has been discoverd then why would we presume any further that life does not exist off our planet? And to the same accord is it feisable to inhabit such planet someday?

 

Who presumes that there's no life outside of our planet? The entire point of searching for "Earthlike Planets" is out of the assumption that there might be life out there. Scientists can't really make a definitive declaration yet, because htere is no supportive evidence *FOR* life outside of earth, but I don't know of many that state definitively that there isn't, either.

 

 

For now, it's a search to see if it's plausible or not. Every discovery of such a planet raises the plausibility level, but doesn't yet supply enough evidence to say either way, so it comes down to scientists arguing their personal beliefs when confronted.

 

There's not yet an absolute "yes" or a "no" in physics, though.

[keelanz]

Who presumes that there's no life outside of our planet? The entire point of searching for "Earthlike Planets" is out of the assumption that there might be life out there. Scientists can't really make a definitive declaration yet, because htere is no supportive evidence *FOR* life outside of earth, but I don't know of many that state definitively that there isn't, either.

 

 

For now, it's a search to see if it's plausible or not. Every discovery of such a planet raises the plausibility level, but doesn't yet supply enough evidence to say either way, so it comes down to scientists arguing their personal beliefs when confronted.

 

There's not yet an absolute "yes" or a "no" in physics, though.

 

I agree with mooey, im sure you'll find a rather large percent of actual scientist would agree that on probability alone life is not exclusive to our own planet.

However as mooey said theres no "absolute" answer until the proof shows itself so we can only speculate on foreign life forms.

 

for the luls

 

peace

[Doc. Josh]

Then that may be my mis understanding, i pressumed that when (alien) is brought up you get labeld a crackpot theroist

[Spyman]

If you claim that people need to wear hats made of tin-foil because aliens are visiting Earth and controlling or reading our minds then you are likely to get labeled as such but not if you belive in the possibility that Jupiter's moon Europa could have an subsurface ocean with potential for extraterrestrial life under its ice crust.

 

Frank Drake for instance is a well acknowledged scientist and Emeritus Professor of Astronomy and Astrophysics, most famous for founding SETI and the Drake equation to estimate the number of detectable alien civilizations in our galaxy.

Edited April 20, 2011 by Spyman

[Doc. Josh]

Spyman, Gratzi Much Thanks.

[Ophiolite]

As per article http://news.discovery.com/space/earth-like-planet-life.html If this has been discovered then why would we presume any further that life does not exist off our planet?

There are several reasons why this discovery should have virtually no impact on our assessment of life beyond the Earth, including reasons for suspecting that life will not be possible on this one.

 

1. If current theories of planetary formation are generally correct then it is virtually certain that Earth like worlds exist. This discovery is not the first planet whose mass is of the same order of magnitude as the Earth.

2. The existence of a planet within the Goldilocks zone in no way assures us that liquid water will be present in quantity, only that it could be present in quantity.

3. The presence of a planet within the Goldilocks zone, with water, gives us zero additional data to support the presence of life, since we do not know the likelihood that life will arise in such a situation.

4. The planet is tidally locked to its parent star. As such we may expect extreme temperatures between the two hemispheres with two possible outcomes. Either very high velocity winds that would place severe restrictions on life forms that might develop, or - more seriously - the risk that the atmospher would freez out on the dark side and thereby disappear in a geologically short time period.

 

In terms of possible colonisation, as the planet is three times the mass of the Earth it is likely that this would be impossible without massive bioengineering of human DNA.

[Doc. Josh]

Great reply OPhiolite, So you would not consider that life could not survive without our personal needs? That infact other life forms adapted a diffrent way of survival?

[Ophiolite]

Great reply OPhiolite, So you would not consider that life could not survive without our personal needs? That infact other life forms adapted a diffrent way of survival?

I hold the view that since we have only a single example of a biosphere, that we cannot make meaningful predictions as to what is possible or probable, until we have a better understanding of how that life arose. There are multiple hypotheses for the process of abiogenesis, but none has been worked out in detail, or verified by observation or experimentation. Until that is done any estimate of possible life forms, or how life originates is going to be a barely educated guess.

[Spyman]

In terms of possible colonisation, as the planet is three times the mass of the Earth it is likely that this would be impossible without massive bioengineering of human DNA.

Gliese 581g could be up to 4.3 times as massive than Earth but the surface gravity is not expected to be higher than 1.7 times of what we have.

 

Surface gravity depends on mass and radius and while a 4 times more massive sphere with roughly the same density would only have a cubic root of 4 greater radius, gravity gets weaker with the square of that change in radius, making surface gravity there 4/4^2/3= ~ 1.6 times that of Earth.

 

A 70 kg. person would not likely weight more than 120 kg. and probably only around 110 kg. which would limit capabilities, but not make it impossible to live there.

 

Physical characteristics

Gliese 581 g has an orbital period of 37 days, orbiting at a distance of 0.146 AU from its parent star. It is believed to have a mass of 3.1 to 4.3 times Earth's and a radius of 1.3 to 2.0 times Earth's (1.3 to 1.5 times larger if predominantly rocky, 1.7 to 2.0 times larger if predominantly water ice). Its mass indicates it is probably a rocky planet with a solid surface. The planet's surface gravity is expected to be in the range of 1.1 to 1.7 times Earth's, enough to hold on to an atmosphere likely to be denser than Earth's.

http://en.wikipedia.org/wiki/Gliese_581_g

[Ophiolite]

Impossible was a poorly chosen word. Impractical would have been better. The load imposed on the muscular and circulatory systems by a constant weight almost twice what we have evolved for would lower quality and length of life.

[Spyman]

Yes I agree, the life there would be very hard indeed, but IF we find out that the conditions there are good for Earth life, otherwise than for the strong gravity, then Earth life will survive and adapt naturally with time, IF we are able to bring it there, no immediate need for bioengineering.

 

Of course since Gliese 581g is NOT just a simple more massive Earth I would suspect that the "other conditions" for Earth life is NOT good at all and might require massive bioengineering or expensive terraforming if even possible at all.

 

Finding a planet like in the science fiction movie Avatar does not seem very likely, but the thoughts of one similar to Earth is very intriguing even without intelligent aliens.

[JohnB]

Ophiolite, you need to read more "Doc" Smith.

[Ophiolite]

Since I've read everything he wrote I can't really read more.