NationStates Jolt Archive

I am by no means expert in affairs pertaining to celestial objects of any sort. I do enjoy reading up on such matters, however. A day or two ago, I was perusing the thread regarding Europa

http://forums.jolt.co.uk/showthread.php?t=371763

when I remembered something that had made me wonder aloud on more than one occasion. In this age of truly amazing stellar photography, thanks to new orbital or other high-power sensing apparatus, I've yet to hear of or see any new images of our closest neighbours - Alpha, Beta and Proxima Centauri.

Every once in a while I get to wondering if anything has been happening on this front - seems straightforward enough to me, checking out the "local" space to get a really clear idea of what's reasonably nearby. So I try searching online.

But every time I've looked online, all I come across are the same three or four pages from the mid-90s, in some cases mirrored at later dates. Like these:

http://homepage.sunrise.ch/homepage/schatzer/Alpha-Centauri.html

http://hyperphysics.phy-astr.gsu.edu/hbase/starlog/strclos.html

The info given is pretty good, but it just seems kinda forgotten, like in the interceding 8 or nine years there's just been no new information gathered. Does that seem strange to anyone but me?

It's not like I'm expecting there to be a twinned Earth or any other fantastic thing orbiting any of the three, but Alpha or Beta could theoretically support 'meaningful' life, and if you're willing to adjust your views on what constitutes 'meaningful' life, then Proxima could very well support some sort of life, too...presumably not the sort of life that puts on ties and rides the subway to work every morning, but some sort of life.

But even if Centaurus proved lifeless or at least without 'meaningful' life, shouldn't we learn more about that nearby trinary anyway? Three suns must have something orbiting them, whatever that may be. Even if life doesn't come into the picture, we could no doubt learn something from what we find in our backyard.

Don't get me wrong - I love seeing all the Hubble photos, and it's great that we can see further and more clearly than ever before. It just strikes me as odd that while we can peruse all sorts of images of things that are millions of light-years away, we still have only older, poor-quality images of our own neighbourhood.

(I really am not inferring some sort of conspiracy to keep us in the dark about Centaurus. I suppose what I'm hoping for is that someone on NS will read this, laugh with derision, and point me in the direction of some info source I hadn't heard of before.)

Any thoughts?

Since the closest approach of the binaries is 11 AU, I can't see there being too many planets - it would take more luck than we had in getting our system.

There are other stars of similar size and color to our own that are not part of a binary system.

Also, actually directly imaging planets even at that close a distance is still beyond our current technology.

Yes, I'd like to go. It would be more interesting than hanging out on this rock.

According to the illustrations near the bottom of this

http://www.eso.org/outreach/eduoff/edu-prog/catchastar/CAS2002/cas-projects/nether_alphacen_1/lifepos.html

page, there could be habitable zones around A or B. That'd give me greater impetus to look, but what do I know?

I'm hoping (nahhh, I'm sure) that others know more about this than I do. Lemme know...!

Since directly imaging a planet as small and cold as the Earth at that distance is probably not yet possible, and if it is, would only be possible by specific equipment, I'm not sure that the existence of a known terrestrial-like planet would be revealed to the public.

^ What he said.

They can determine the existence of planets by observing how the star wobbles, but this only really works with *big* planets.

http://en.wikipedia.org/wiki/Planets#Extrasolar_planets

You might find that interesting :)

Since directly imaging a planet as small and cold as the Earth at that distance is probably not yet possible, and if it is, would only be possible by specific equipment, I'm not sure that the existence of a known terrestrial-like planet would be revealed to the public.

Well Legs, like I said initially, I don't really care if there isn't an Earth-like planet orbiting A, B or Prox - I'd just like to know more about 'em, and what does orbit 'em... if anything.

On the Europa thread, someone (can't remember who) said it was because planets don't emit radiation that we can't readily spot an orbiting body, even one as theoretically close to us as whatever might be circling Centaurus.

I thought about that for a moment, and responded by saying that while planets don't emit radiation, isn't it true that they absorb or reflect certain types of radiation (emitted by their sun)? Like light or heat radiation?

I didn't get a response to that. Oh well. Maybe it was just too dumb a notion to garner a response.

I dunno...!

^ What he said.

They can determine the existence of planets by observing how the star wobbles, but this only really works with *big* planets.

http://en.wikipedia.org/wiki/Planets#Extrasolar_planets

You might find that interesting :)

I'll look. Thanks, Kanabia.

I'll look. Thanks, Kanabia.

You're welcome :)

My bad, though. The main article is http://en.wikipedia.org/wiki/Extrasolar_planet, and they already have pictures of several planets around various stars, albeit huge gas giants. I guess it won't be long until we can see smaller ones :)

Dobbs, the problem with planets as cool as the Earth or Europa is that they emit in the infrared - not in visible light. You'll only see them in visible light if they're being illuminated by the star in reference to the observer's position.

From our point of view, that would mean seeing that illuminated speck very close to a bright object - the parent star - as that planet began its orbit around the other side of that star.

To see the planet side on, in the infrared, we run up against a problem called diffraction limiting. The longer the wavelength, the larger the mirror you need to achieve the ability to discern features of a certain size.

Infrared light requires much larger mirrors than visible light. And the larger the mirror, the harder it is to steer and focus accurately - or even produce.

There are techniques for getting around the diffraction limit, but they are mostly held by the US Ballistic Missile Defense Organization, which is working on the same type of problem - spotting a moving cool warhead against the background of the Earth. They have evidently only recently achieved success in what is called "superresolution" - the ability to achieve resolution far past the diffraction limit.

Well Legs, like I said initially, I don't really care if there isn't an Earth-like planet orbiting A, B or Prox - I'd just like to know more about 'em, and what does orbit 'em... if anything.

On the Europa thread, someone (can't remember who) said it was because planets don't emit radiation that we can't readily spot an orbiting body, even one as theoretically close to us as whatever might be circling Centaurus.

I thought about that for a moment, and responded by saying that while planets don't emit radiation, isn't it true that they absorb or reflect certain types of radiation (emitted by their sun)? Like light or heat radiation?

I didn't get a response to that. Oh well. Maybe it was just too dumb a notion to garner a response.

I dunno...!

Yes, they do reflect radiation, however compared to the star, their luminocity is very low (sic, look at Pluto)... From this distance (>4.5ly) even a completely reflective planet the size of jupiter would not be viewable.

Also, the estimantes on a planet effecting Proxima Centuri's, is estimated as being somewhere near 80% the size of jupiter... (also, about 75% of the modeling done on proxima, can account all pertubations in its orbit, as a result of the Rigel Kentaurus A/B pair; so even then, it's not even close to certain that there is a planet there effecting the motion).

Hmmm. Tricky stuff. Maybe once that "superresolution" dealie has applications other than military, we'll see some developments.

Here's hoping-!

*raises glass to Legs*

Well Legs, like I said initially, I don't really care if there isn't an Earth-like planet orbiting A, B or Prox - I'd just like to know more about 'em, and what does orbit 'em... if anything.

On the Europa thread, someone (can't remember who) said it was because planets don't emit radiation that we can't readily spot an orbiting body, even one as theoretically close to us as whatever might be circling Centaurus.

I thought about that for a moment, and responded by saying that while planets don't emit radiation, isn't it true that they absorb or reflect certain types of radiation (emitted by their sun)? Like light or heat radiation?

I didn't get a response to that. Oh well. Maybe it was just too dumb a notion to garner a response.

I dunno...!
The reflected heat and light emissions from a planetary object are inconsequental by comparison with their star and are effectively blanked out. The current method of determining whether a start has planets is to measure the "wobble" of a star about its axis and infer the existence of Jupiter-sized mass ( or larger ) from an analysis of that "wobble."

Hmmm. Tricky stuff. Maybe once that "superresolution" dealie has applications other than military, we'll see some developments.

Here's hoping-!

*raises glass to Legs*

There are civilians working on superresolution, but they don't seem to be applying it to anything except photography. Not sure if everyone needs a camera with twice the resolution we're already getting.

Most of the techniques are software based.

Dobbs, the problem with planets as cool as the Earth or Europa is that they emit in the infrared - not in visible light. You'll only see them in visible light if they're being illuminated by the star in reference to the observer's position.

From our point of view, that would mean seeing that illuminated speck very close to a bright object - the parent star - as that planet began its orbit around the other side of that star.

To see the planet side on, in the infrared, we run up against a problem called diffraction limiting. The longer the wavelength, the larger the mirror you need to achieve the ability to discern features of a certain size.

Infrared light requires much larger mirrors than visible light. And the larger the mirror, the harder it is to steer and focus accurately - or even produce.

There are techniques for getting around the diffraction limit, but they are mostly held by the US Ballistic Missile Defense Organization, which is working on the same type of problem - spotting a moving cool warhead against the background of the Earth. They have evidently only recently achieved success in what is called "superresolution" - the ability to achieve resolution far past the diffraction limit.
Excellent elucidation, WL! :)

The next generation of orbital telescopes will be one which focuses on the infrared portion of the spectrum. I forget the name of it just now, but it should be operational within a couple of years.

There are civilians working on superresolution, but they don't seem to be applying it to anything except photography. Not sure if everyone needs a camera with twice the resolution we're already getting.
Good for taking telephoto shots of the neighbor's daughter. :D

Also, the estimantes on a planet effecting Proxima Centuri's, is estimated as being somewhere near 80% the size of jupiter... (also, about 75% of the modeling done on proxima, can account all pertubations in its orbit, as a result of the Rigel Kentaurus A/B pair; so even then, it's not even close to certain that there is a planet there effecting the motion).

Are you saying the amount of 'wobble' for Proxima can be accounted for by the pull of A and B? I'm not clear on this from your post, I hope I'm not misunderstanding you.

In terms of life, hey - I'd be happy to find anything at all, from microbe to mammal. I have doubts that we'll find anything like that within my own lifetime, but we've only been able to determine that extrasolar planets do indeed exist within my own lifetime, so who knows?

Still, it's no doubt more credible that should we find life elsewhere, it would be far more likely to be a microbe than a mammal.

Excellent elucidation, WL! :)

The next generation of orbital telescopes will be one which focuses on the infrared portion of the spectrum. I forget the name of it just now, but it should be operational within a couple of years.
It's not a coincidence that the Hubble is actually a modified version of a reconaissance satellite that had already been in production and used for some years BEFORE the Hubble.

And it's not a coincidence that SBIRS-High and SBIRS-Low are already working - when astronomers are talking about putting a high resolution infrared telescope in space to try to image distant planets.

It just seems a shame to me that all these nifty cool developments seem to come from military R & D. I know more than likely I'm in the minority on that score, but I'm pretty sure you know my feelings regarding war, so I'm not going there.

*sigh*

If it already exists, I hope civilians don't have to needlessly replicate the technology - seems wasteful, when it could just be shared (but if it's military...well, I just don't see it being shared. It's unfortunate.).

Thanks, guys.

Are you saying the amount of 'wobble' for Proxima can be accounted for by the pull of A and B? I'm not clear on this from your post, I hope I'm not misunderstanding you.

In terms of life, hey - I'd be happy to find anything at all, from microbe to mammal. I have doubts that we'll find anything like that within my own lifetime, but we've only been able to determine that extrasolar planets do indeed exist within my own lifetime, so who knows?

Still, it's no doubt more credible that should we find life elsewhere, it would be far more likely to be a microbe than a mammal.

Yeah, typically what they do, when they find a wobble, is create a gravitational model. And then "play" witht he model to match criteria of the initial measurement....

About 75% of the modeling, was accounted for, with only Rigel Kentaurus A & B in the model, the rest could be explained by a planet, of about 80% jupiter's mass.... So it's not even certain that there needs to be a planet to describe the wobble in Kentaurus C's path... Basically, you can say, there is a ~75% chance of there being no planet there.... Not the best odds, but doesn't totally discount the possibility either.

It just seems a shame to me that all these nifty cool developments seem to come from military R & D. I know more than likely I'm in the minority on that score, but I'm pretty sure you know my feelings regarding war, so I'm not going there.

*sigh*

If it already exists, I hope civilians don't have to needlessly replicate the technology - seems wasteful, when it could just be shared (but if it's military...well, I just don't see it being shared. It's unfortunate.).

Thanks, guys.


For a while there, we were under the illusion that the space program in the US drove US technological innovation.

But the US space program was driven by military technology. You'll note that the Atlas and Titan boosters used in the first part of the US space program were ICBMs.

Even the Shuttle had military requirements.

The military seems to share some technology within 5 to 10 years. Cheaper in most cases to wait for it - by then they have the bugs worked out.

Umm... Has anyone considered planetary bodies at a distance, orbiting both stars in a manner similar to Proxima Centauri? It seems to me that there is still room for a significant amount of crud at a distance.

Umm... Has anyone considered planetary bodies at a distance, orbiting both stars in a manner similar to Proxima Centauri? It seems to me that there is still room for a significant amount of crud at a distance.

I've considered it, but even then the model is unstable..

These aren't two "suns" in stable circular orbit of one another. Rigel Kentaurus A, and Rigel Kentaurus B, are in highly eliptical orbits of each other (varying distances of 11 and 36 AU's (this would be like having another system near our own, each in orbit, that mesh around the orbits of Saturn and Neptune, sliding around one another)... Any "far" planets would not be within any habitable zones of the stars (and would likely be gas giants, or failed stars)... Also, they would possess a highly elipsoid orbit, verying in intensity between each of the stars, along with the danger (as I've modeled) of falling between the stars, and propeled by both stars gravity out of the system...

The gravity well around the region, just does not make for pretty orbital models, as they do in single star systems, where all the planets are in marginal elipses.... But maked for very chaotic orbits, and presents lots of questions as to the ability of planetary bodies to form coherantly during the formation of the system.... It's likely all we will ever find there is asteroids, and debries from failed planets.

Not to mention the fact that if you go out any real distance at all, things get very cold.

and if you're willing to adjust your views on what constitutes 'meaningful' life, then Proxima could very well support some sort of life, too...presumably not the sort of life that puts on ties and rides the subway to work every morning, but some sort of life.

Nothing from Earth could survive near Proxima for very long. Firstly, it's a red dwarf. This in itself presents two problems -- firstly, plants would have trouble photosynthesising. Secondly, any planet capable of harbouring human life is going to have to be very close indeed to get even slightly warm enough.

The second largest problem is the fact that it is a flare star. Given how close a planet would need to be to keep warm, I don't think I need to say why this is a problem.

Alpha and Beta aren't exactly promising places either.

It's not just the stars themselves that you have to bear in mind when deciding on whether a place could support life, remember. If there's a huge gas giant right next to the green belt, any Earth-like planet that develops in that place will be torn to pieces, much like what some people believe happened to a planet which is now the asteroid belt of our own star system.



If by 'adjust your views on what constitutes meaningful life' you mean something completely alien, not found on Earth in any shape or form, then the parameters are too vague to say one way or another. If evolution is anything like the accurate model it is hyped to be, then there may well be lifeforms existing in places we could never even dream of existing. There could be things living in the sun for all we know. Or in space itself. Heck, the rocks on Mars could be alive and we simply haven't noticed yet. But until we actually find something like that we only have one model to work off -- Earth. It's always been my opinion that different life from different places will require different things to survive, but it seems scientists are largely fixated on the idea of all life being Earth-like life for the time being.

Beta Centauri (aka Hadar) is not a nearby star. It's a blue giant start located over 500 light years away. If you are talking about the lesser component of the Alpha Centauri binary system, it's called AlphaCentauri-B.

Just a random fact. :)

Could there be moons, that could support life, around a gas giant, or would they be too cold.

Could there be moons, that could support life, around a gas giant, or would they be too cold.

Assuming that all things were ideal, it's possible... if the two orbits around each other resulted in the moon always facing towards the sun. Even if that wasn't the case, they could hibernate, I suppose, or live for half a year, give birth to whatever offspring/seedling which would lie dormant until the sun is back and it gets warm enough...

(I do have a very varied view of what shape life could take, so whilst I expect most people more knowledgeable than me would disagree, I choose not to accept their counter-statements that all life will follow an earth-standard.)

Assuming that all things were ideal, it's possible... if the two orbits around each other resulted in the moon always facing towards the sun. Even if that wasn't the case, they could hibernate, I suppose, or live for half a year, give birth to whatever offspring/seedling which would lie dormant until the sun is back and it gets warm enough...

(I do have a very varied view of what shape life could take, so whilst I expect most people more knowledgeable than me would disagree, I choose not to accept their counter-statements that all life will follow an earth-standard.)
I've always found it strange that people alwys assume everything would be like it is here on earth. Life has an amazing ability to adapt to different conditions, from hot srings to deserts to glaciers, I'm sure anything we would find on another planet would be wastly different from anything we see here.

Could there be moons, that could support life, around a gas giant, or would they be too cold.

If I picked up the earth (I've been working out) and threw it into the depths of freezing interstellar space, life would still survive for billions, (tens of billions?) of years. Life on earth extends miles down into the crust. There are bacteria down there who don't give a damn about us surface dwellers. They don't need the sun to survive. They are chemosynthetic and warmed by the heat of the earth's core. If there are places in the moon's crust where there is water in the rocks, they could live there. It's even possible that there is life on the moon. If not native, then blown there in a chuck of earth rock.

But no green woman. Sorry Kirk.

These aren't two "suns" in stable circular orbit of one another. Rigel Kentaurus A, and Rigel Kentaurus B, are in highly eliptical orbits of each other (varying distances of 11 and 36 AU's (this would be like having another system near our own, each in orbit, that mesh around the orbits of Saturn and Neptune, sliding around one another)... Any "far" planets would not be within any habitable zones of the stars (and would likely be gas giants, or failed stars)... Also, they would possess a highly elipsoid orbit, verying in intensity between each of the stars, along with the danger (as I've modeled) of falling between the stars, and propeled by both stars gravity out of the system...

Hey! Do you have a link that points to the result of your models? preferably a paper published by a peer reviewed journal? Because these guys would beg to differ. (http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?1997AJ....113.1445W)

Offtopic: Dobbsworld? Got deleted again?