Planet of Proxima Centauri?

On Wed, 24 Aug 2016 13:11:21 -0700 (PDT), Quadibloc
wrote:

On Wednesday, August 24, 2016 at 1:03:41 PM UTC-6, Chris L Peterson wrote:

Why?

It's unlikely to have an atmosphere, despite a mass somewhat greater than
Earth's, and receiving less heat from the Sun than the Earth.

I agree that a lack of atmosphere argues against life. However, from
what I've read, the existence or lack thereof of an atmosphere remains
largely a guess at this point.

wrote:
On Wednesday, August 24, 2016 at 3:03:41 PM UTC-4, Chris L Peterson wrote:
On Wed, 24 Aug 2016 11:18:10 -0700 (PDT), Quadibloc
wrote:

The planet is now confirmed:

http://arstechnica.com/science/2016/...-sized-planet/

It is quite Earthlike in a number of respects, but still very unlikely to have
life.

Why?

For one thing, the planet is likely tidally locked and therefore unlikely to have life.





How many planets in the Solar system are tidally locked?

On Wednesday, August 24, 2016 at 9:32:10 PM UTC+1, Mike Collins wrote:


How many planets in the Solar system are tidally locked?

Do the experiment.

Walk/orbit a central object with an outstretched arm pointing at the object imitating the moon's monthly motion around the Earth and you get the answer as to why we see the same face of the moon constantly.

The empirical voodoo of 'tidal locking' and suddenly everyone 'believes' in a rotating moon. It is so bizarre that you have to be a walking corpse to accept it.

https://books.google.ie/books?id=OdC...ge&q&f=fa lse

I even showed you where Newton mixed up revolution for rotation in Kepler's Somnium and that Kepler's theory for planetary motions is based on a non-rotating moon -

"The Sun and the Earth rotate on their own axes...The purpose of this
motion is to confer motion on the planets located around them;on the
six primary planets in the case of the Sun,and on the moon in the case
of the Earth.On the other hand the moon does not rotate on the axis of
its own body,as its spots prove " Kepler

Such a strange bunch, willing to promote Kepler's 'laws of motion' even though he didn't write any yet Kepler's conjecture for planetary motions is actually quite good as the motion of the larger object may impart motion on the smaller object but Kepler's notion extends out to galactic orbital motion and our solar system's motion and those of the other stars through space and in a circle around the galactic center

Huge,huge electromagnetic signatures but lost to the clockwork solar system hopeless cases like yourself.

On 24/08/2016 20:47, wrote:
On Wednesday, August 24, 2016 at 3:03:41 PM UTC-4, Chris L Peterson wrote:
On Wed, 24 Aug 2016 11:18:10 -0700 (PDT), Quadibloc
wrote:

The planet is now confirmed:

http://arstechnica.com/science/2016/...-sized-planet/

It is quite Earthlike in a number of respects, but still very unlikely to have
life.

Why?

For one thing, the planet is likely tidally locked and therefore unlikely to have life.

It would not have been tidally locked at the outset and there would
still be a habitable zone at the terminator even when it was. The key is
having all three phases of water and an atmosphere to support it.

Tidal action is only really a driver for colonisation of the land by
aquatic creatures that need to survive being stranded on the shore.

Earth's deep sea vent colonies don't depend on solar energy for anything
so it is entirely possible that there is life on Europa if only we could
explore for it without contaminating the eco system.

Life here meaning some self replicating slime or other not LGM.

It would be very interesting to see what genetic code they used and what
cell structures evolved independently elsewhere.

Regards,
Martin Brown

On Wednesday, August 24, 2016 at 4:30:57 PM UTC-4, Chris L Peterson wrote:
On Wed, 24 Aug 2016 12:47:27 -0700 (PDT), wrote:

On Wednesday, August 24, 2016 at 3:03:41 PM UTC-4, Chris L Peterson wrote:
On Wed, 24 Aug 2016 11:18:10 -0700 (PDT), Quadibloc
wrote:

The planet is now confirmed:

http://arstechnica.com/science/2016/...-sized-planet/

It is quite Earthlike in a number of respects, but still very unlikely to have
life.

Why?

For one thing, the planet is likely tidally locked and therefore unlikely to have life.

Why not? It is clear why tidal locking would pose problems for complex
life, especially for animal life, but why for the sort of
single-celled life that dominated Earth for a couple billion years?
And why assume that life which formed before the planet was tidally
locked wouldn't evolve in ways that would allow it to adapt?

Tidal locking brings with it all sorts of other potential problems. High winds, entire atmosphere freezing on the dark side, smaller likelihood of an atmosphere-preserving magnetic field, etc.

Libration is also likely so that the "twilight zone" is alternately baked and frozen over the course of the planet's year.

Of course, it has been speculated that life on Earth could have originated underground, but if true then life could theoretically -originate- (but not flourish) on planets of many other stars.

What makes this newly discovered planet special is that it is the closest exoplanet, and therefore potentially the most accessible for direct exploration.

On Wednesday, August 24, 2016 at 4:32:10 PM UTC-4, Mike Collins wrote:
wrote:
On Wednesday, August 24, 2016 at 3:03:41 PM UTC-4, Chris L Peterson wrote:
On Wed, 24 Aug 2016 11:18:10 -0700 (PDT), Quadibloc
wrote:

The planet is now confirmed:

http://arstechnica.com/science/2016/...-sized-planet/

It is quite Earthlike in a number of respects, but still very unlikely to have
life.

Why?

For one thing, the planet is likely tidally locked and therefore unlikely to have life.





How many planets in the Solar system are tidally locked?

Irrelevant question.

On Thursday, August 25, 2016 at 3:31:05 AM UTC-4, Martin Brown wrote:
On 24/08/2016 20:47, wrote:
On Wednesday, August 24, 2016 at 3:03:41 PM UTC-4, Chris L Peterson wrote:
On Wed, 24 Aug 2016 11:18:10 -0700 (PDT), Quadibloc
wrote:

The planet is now confirmed:

http://arstechnica.com/science/2016/...-sized-planet/

It is quite Earthlike in a number of respects, but still very unlikely to have
life.

Why?

For one thing, the planet is likely tidally locked and therefore unlikely to have life.

It would not have been tidally locked at the outset and there would
still be a habitable zone at the terminator even when it was.

pedantry deleted

It is very likely tidally locked NOW.

The use of the word "habitable" is the issue here. What we really want to know is not if the planet is merely "habitable," but whether it in fact DOES have life.

On 25/08/2016 12:47, wrote:
On Thursday, August 25, 2016 at 3:31:05 AM UTC-4, Martin Brown wrote:
On 24/08/2016 20:47, wrote:
On Wednesday, August 24, 2016 at 3:03:41 PM UTC-4, Chris L Peterson wrote:
On Wed, 24 Aug 2016 11:18:10 -0700 (PDT), Quadibloc
wrote:

The planet is now confirmed:

http://arstechnica.com/science/2016/...-sized-planet/

It is quite Earthlike in a number of respects, but still very unlikely to have
life.

Why?

For one thing, the planet is likely tidally locked and therefore unlikely to have life.

It would not have been tidally locked at the outset and there would
still be a habitable zone at the terminator even when it was.

pedantry deleted

It is very likely tidally locked NOW.

The use of the word "habitable" is the issue here. What we really want to know is not if the planet
is merely "habitable," but whether it in fact DOES have life.

That might be possible to do observationally if it can be shown that the
planets atmosphere is wildly out of equilibrium. The snag I see for this
one is that it may well not have any atmosphere remaining.

Even so it might perhaps have had life at some point in the past -
likewise for Mars too (although it looks a bit too sterile). There is
still a hint of methane emissions that could be something real.

Regards,
Martin Brown

On Wednesday, August 24, 2016 at 2:32:10 PM UTC-6, Mike Collins wrote:
On Wed, 24 Aug 2016 11:18:10 -0700 (PDT), Quadibloc
wrote:

For one thing, the planet is likely tidally locked and therefore unlikely to have life.

How many planets in the Solar system are tidally locked?

None whatsoever.

John Savard

On Thu, 25 Aug 2016 04:23:07 -0700 (PDT), wrote:

For one thing, the planet is likely tidally locked and therefore unlikely to have life.

Why not? It is clear why tidal locking would pose problems for complex
life, especially for animal life, but why for the sort of
single-celled life that dominated Earth for a couple billion years?
And why assume that life which formed before the planet was tidally
locked wouldn't evolve in ways that would allow it to adapt?

Tidal locking brings with it all sorts of other potential problems. High winds, entire atmosphere freezing on the dark side, smaller likelihood of an atmosphere-preserving magnetic field, etc.

Yes. None of which seem likely to pose significant problems for simple
life forms.

Libration is also likely so that the "twilight zone" is alternately baked and frozen over the course of the planet's year.

Sure. But there's a lot of planet besides the twilight zone.