Earth-like exoplanet discovered around Proxima Centauri

Craig B said:
As regards the atmosphere, it has been noted that if the planet is in a position to make a transit of the star as seen from Earth, then some important information about the atmosphere, including composition and thickness, may become available.

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RecoveringYuppy said:
Depends on if it transits. I think the discovers of the planets estimate a 1 or 2 percent chance of that. This planet is very close to an active star. I'd expect it's atmosphere is going to match the stars stellar wind.

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Right.

This has been done - using transits, including grazing ones, to get a handle on an exoplanet's atmospheric composition, scale height, presence of clouds, etc - already. Though not for an exoplanet as small as Proxima b (IIRC).

If there are no transits, no chance whatsoever of being able to estimate these, before ~2065?

How about if something like a TPF or Darwin (see post upthread) were to be up and working, perhaps with some instruments specifically designed to investigate exo-atmospheres (what would they be)?
 
Craig B said:
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I suppose some information about temperature can be inferred from the luminosity of the star and the distance of the planet from it, both already known.
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True, but not particularly robust estimates ... depends too much on the models (e.g. are there atmospheric winds which transport heat from the dayside to the nightside? If so, what effect do they have on surface temps?)

Could a TPF-like or Darwin-like facility produce data which could be used to estimate surface temperature ranges?

But the rest of the points you raise still look like the object of speculation at present.
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Hmm ... given that both the TPF and Darwin are/got further than just speculation, and given my time frame (within the next ~half century), I think we can do better than speculation ;)
 
The Great Zaganza said:
Also, an 11-day year is not very practical for us.
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Not sure why.
If (as they seem to think) it has little to no axial tilt then there won't be any seasons, so why would a short year (which would be fairly meaningless without seasons) make a difference?
 
If the planet doesn't transit its star, could a transit of a more distant star by the planet be used to gain any data, assuming there is a star in such a position for that to occur which may be a bit of a long shot.
 
There is, of course, something that will get to Proxima b in about four years.... radio waves.

If we were to use a radio telescope to direct a powerful radio signal toward Proxima b, on a broad spectrum of radio frequencies, we might get the answer we have been looking for

Now while the likelihood of there being advanced intelligent life in the Proxima system is probably very low, the cost of doing this is minuscule when compared with the cost of developing and sending any kind of probe there. It also has the added bonus that any reply would only be a few years in coming.

If we hear nothing, it would prove nothing, but if we got a reply... just WOW!!


(see what I did there?)
 
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Tolls said:
Not sure why.
If (as they seem to think) it has little to no axial tilt then there won't be any seasons, so why would a short year (which would be fairly meaningless without seasons) make a difference?
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Because planet in such a close orbit is probably tidally locked and always presents the same face to its sun, as the Moon does to the Earth. So, a hot bright side and a cold dark side, very unlike our own planet.
 
Craig B said:
Because planet in such a close orbit is probably tidally locked and always presents the same face to its sun, as the Moon does to the Earth. So, a hot bright side and a cold dark side, very unlike our own planet.
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Life doesn't have to be like our own. There even is life on this planet that requires no 'seasons" and lives in the harshest of conditions

http://ocean.si.edu/ocean-videos/hydrothermal-vent-creatures

The water temperature at hydrothermal vents is in the order of 400°C (750°F)... four times the boiling point of water, except that it doesn't boil because of the pressure; over 1½ tons per square inch, (250 atmospheres, or almost 3 times the pressure on Venus)... and yet, life thrives in these extremely harsh conditions.

IMO, when/if we, as a species, ever make our way out of the Solar System to planets around other stars, we are going to have to radically alter our concepts and definitions of what constitutes, "life".
 
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smartcooky said:
There is, of course, something that will get to Proxima b in about four years.... radio waves.

If we were to use a radio telescope to direct a powerful radio signal toward Proxima b, on a broad spectrum of radio frequencies, we might get the answer we have been looking for

Now while the likelihood of there being advanced intelligent life in the Proxima system is probably very low, the cost of doing this is minuscule when compared with the cost of developing and sending any kind of probe there. It also has the added bonus that any reply would only be a few years in coming.

If we hear nothing, it would prove nothing, but if we got a reply... just WOW!!
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I agree ... passive (listening) and active (messaging) SETI, are valid and relatively efficient tests.

(Of course, the 'possibility' of a response, is entirely dependent on personal assumptions).

smartcooky said:
(see what I did there?)
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(Groan! ... :) )
 
SelfSim said:
I agree ... passive (listening) and active (messaging) SETI, are valid and relatively efficient tests.

(Of course, the 'possibility' of a response, is entirely dependent on personal assumptions).
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Well then, I will personally assume "that" a response "is" highly "possible" and that will cause it to be so.

Up to now I have been assuming "that" the "possibility" of a response was dependent on "the" incidence "of" existence of ETI; but I'm not at all surprised that you make it "entirely" dependent on my state of mind.
 
Craig B said:
Well then, I will personally assume "that" a response "is" highly "possible" and that will cause it to be so.

Up to now I have been assuming "that" the "possibility" of a response was dependent on "the" incidence "of" existence of ETI; but I'm not at all surprised that you make it "entirely" dependent on my state of mind.
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What we'd call 'evidence of ETI' is related to how we think .. yes.
The data we'd gather leading towards establishing what we'd call 'evidence', is related to the senses we have, and how we think about them .. yes.

What you could argue, is that it achieves your goals to imagine that ETI exists .. yes.
 
SelfSim said:
What we'd call 'evidence of ETI' is related to how we think .. yes.
The data we'd gather leading towards establishing what we'd call 'evidence', is related to the senses we have, and how we think about them .. yes.

What you could argue, is that it achieves your goals to imagine that ETI exists .. yes.
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I completely failed to parse this
 
We are talking Intelligence here: something capable of acting in a way that's distinct from inert matter.

So we would notice it just by comparing it to definitely non-intelligent systems.

Atmospheric composition will always be a dead giveaway.
 
smartcooky said:
I completely failed to parse this
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Just stating the painfully obvious .. Ie: what we regard as evidence of ETI, (such as a response to our own initially sent message to say Proxima b), is a function of our human physiology. I mean how else could we regard such a response? For someone with severe brain damage, I would think it would be very difficult to regard it as evidence of anything. Hence its obvious its a function of our brains and senses (human physiology), isn't it?
 
SelfSim said:
What you could argue, is that it achieves your goals to imagine that ETI exists .. yes.
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Yes if I'm looking for something I could argue that imagining I've found it will help me in fact to find it; though the imagined event and the real event are not the same. But what you first wrote was rather different, namely
the 'possibility' of a response, is entirely dependent on personal assumptions​
My bold.
 
Why would any response be based on my personal assumptions


e.g.. We broadcast a transmission that contains the first fifty prime numbers.

Nine years later, a broadcast arrives from the direction of Proxima Cen that repeats the first 50 and follows up with the next 50 prime numbers.

Since there is no natural phenomena that generates prime numbers, the assumption that an intelligence must have generated the second lot of primes would not just be down to my personal assumption.
 
SelfSim said:
... And intelligence comes from where?
... Oh yes .. us!



Well yes. I mean after all, we don't regard ourselves as atmosphere do we?
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nope - any form of intelligence will affect its environment in ways non-intelligent things will not.
If they don't then they are not intelligent.

You've watched too much Star Trek I fear: intelligence is as intelligence does.
 
smartcooky said:
Why would any response be based on my personal assumptions

e.g.. We broadcast a transmission that contains the first fifty prime numbers.
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What are your assumptions for transmitting in a particular band?
What are your assumptions for the period of transmission?
What are your assumptions for sending a narrowband or a broadband transmission?
What are your assumptions for the pulse duty cycles?
What are your assumptions for selecting a particular radiated power?

... (etc, etc).

smartcooky said:
Nine years later, a broadcast arrives from the direction of Proxima Cen that repeats the first 50 and follows up with the next 50 prime numbers.
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What are your assumptions for receiving in a particular band?
What are your assumptions for looking for a particular the period of transmission?
What are your assumptions behind your decision to look for a narrowband or a broadband transmission?
What are your assumptions for looking for specific pulse duty cycles?
What are your assumptions for selecting a particular receiver noise mitigation strategy?

... (etc, etc).

smartcooky said:
Since there is no natural phenomena that generates prime numbers, the assumption that an intelligence must have generated the second lot of primes would not just be down to my personal assumption.
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Perhaps not.
But you still had to make personal assumptions in setting up the link (see above).
 
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