Starship Asterisk*

Gliese 832c: The Closest Potentially Habitable Exoplanet

Explanation: This planet is only 16 light years away -- could it harbor life? Recently discovered exoplanet Gliese 832c has been found in a close orbit around a star that is less bright than our Sun. An interesting coincidence, however, is that Gliese 832c receives just about the same average energy from its parent star as does the Earth. Since the planet was discovered only by a slight wobble in its parent star's motion, the above illustration is just an artistic guess of the planet's appearance -- much remains unknown about Gliese 832c's true mass, size, and atmosphere. If Gliese 832c has an atmosphere like Earth, it may be a super-Earth undergoing strong seasons but capable of supporting life. Alternatively, if Gliese 832c has a thick atmosphere like Venus, it may be a super-Venus and so unlikely to support life as we know it. The close 16-light year distance makes the Gliese 832 planetary system currently the nearest to Earth that could potentially support life. The proximity of the Gliese 832 system therefore lends itself to more detailed future examination and, in the most spectacularly optimistic scenario, actual communication -- were intelligent life found there.

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Say what you like about the artist's guess of Gliese 832c, they absolutely nailed Earth.

If we are going to devise ways to probe the atmospheres of exoplanets, Gliese 832c must be one of the very first targets. If not the very first.

Ann

Communicate? We can't even see the thing! How about somebody design a hypothetical telescope that can see exo planets. How about somebody design a hypothetical antenna array that can receive television and radio transmissions coming from an exo planet. For the telescope, use current CCD sensitivities, then maybe design one with a CCD that is 1,000,000 times more sensitive. For the antenna array, use sensitivities that were available at the time when the movie Contact premiered, then with current sensitivities, then with 1,000,000 times more sensitive than current capabilities. Assume the civilization on the exo planet exactly parallels ours; so, for television and radio transmissions, however many light years away the observation planet is, is how long ago one must baseline the civilization's radio wave emissions. Since Gliese 832c is 16 light years away, then the baseline is Earth's emissions in the mid 90's.

These are not a trivial problems I'm proposing. I wouldn't be at all surprised that some genius types have already done something like this for the fun of it. I'd just like to see the results.

When we can only JUST detect planets like Glieze 832c, it's a bit much to ask about moons, but in the Solar System, Earth is unique in it's large, single Moon. How important is that in allowing an atmosphere that will permit life?

How detectable, in relation to the atmosphere of such a planet, would a Moon-analogue be? Would it not be better to target that as a detection object, and then target those that have one as most likely to have a viable atmosphere?

John

Too many if's, but's & maybe's & even the APOD is an artist's impression.
Waste of space ??????

Frank2014 wrote:Waste of space ??????

No, not at all.

scientists need to stop asking silly questions like are we alone in the universe - the search for extraterrestrial life is not on the human agenda. in general, the search for extraterrestrial blueberries or exoflowers and the exobees that pollinate them is the business of botanists that understand the scheme of nature and the issue of compatibility with terrestrial order. human being explore the heavens for terrestrial exoplanets because it is in the spirit and substance of human being to do so. there is the explorers romance with uncharted terrain and the need to witness new vistas and survey new skies while holding what is known of earth deep in the heart and soul.
despite questionable technical means to identify exoplanets the gliese 832 system appears to offer a complete study on planetary geology and stellar mechanics. from what is known of stellar mechanics the planetary lot of other star systems can be extrapolated - star systems such as zeta reticuli and 16 cygni and alpha centauri.
artists rendering is crucial in understanding exoplanet dynamics. if the physical character of gliese 832c is indeed what it is deemed to be then a fully cloud covered exoplanet may be expected - and don't forget the possibility of cloud covered moons and rings galore.

Scabulus wrote:Communicate? We can't even see the thing! How about somebody design a hypothetical telescope that can see exo planets.

We already have telescopes that can directly detect exoplanets. And have.

How about somebody design a hypothetical antenna array that can receive television and radio transmissions coming from an exo planet.

We already have radio telescopes that can do this.

For the telescope, use current CCD sensitivities, then maybe design one with a CCD that is 1,000,000 times more sensitive.

Impossible. Current CCDs are very close to perfect, meaning that they detect nearly 100% of the photons that strike them. They can't be made more sensitive. All you can do is collect more photons, meaning you need a larger aperture telescope. But exoplanets actually reflect plenty of light for many current telescopes and detectors to record. The problem is that the planets are lost in the glare of their stars.

For the antenna array, use sensitivities that were available at the time when the movie Contact premiered, then with current sensitivities, then with 1,000,000 times more sensitive than current capabilities. Assume the civilization on the exo planet exactly parallels ours; so, for television and radio transmissions, however many light years away the observation planet is, is how long ago one must baseline the civilization's radio wave emissions. Since Gliese 832c is 16 light years away, then the baseline is Earth's emissions in the mid 90's.

And the money comes from where? The chance of finding intelligent life with technology similar to ours on any nearby planets is vanishingly small. Is it worth looking? Sure. But it has to be done with instruments that primarily serve another purpose.

JohnD wrote:How detectable, in relation to the atmosphere of such a planet, would a Moon-analogue be?

Detecting a large moon- nearly a binary planet as with the Earth-Moon- is within the capabilities of current instrumentation, and will be easier with planned instrumentation. If there are exoplanets with large moons, enough data may already have been captured to detect them, once that data has been more fully analyzed.

Would it not be better to target that as a detection object, and then target those that have one as most likely to have a viable atmosphere?

I think that new ways of looking at existing data are always being explored. New targets present themselves as new analysis techniques are developed. The instrumentation is the same in any case.

On another subject, what would an intelligent species, with the same scientific capabilities as we currently have, see when they look at our rather complex planetary/solar system? Would they be able to determine the orbit of our several planets, and the possibility of our Earth orbiting in the "goldielocks zone?"

I bring this up, because it seems like we rarely see examples of multi-planet systems through all these fascinating techniques currently being used to find planets. What's the likelihood of us missing some Earth-like planets, because the systems we are observing are dominated by much larger planets? Maybe potentially habitable planets (or moons) are even more common and possibly closer...

ddorn777 wrote:On another subject, what would an intelligent species, with the same scientific capabilities as we currently have, see when they look at our rather complex planetary/solar system? Would they be able to determine the orbit of our several planets, and the possibility of our Earth orbiting in the "goldielocks zone?"

I bring this up, because it seems like we rarely see examples of multi-planet systems through all these fascinating techniques currently being used to find planets. What's the likelihood of us missing some Earth-like planets, because the systems we are observing are dominated by much larger planets? Maybe potentially habitable planets (or moons) are even more common and possibly closer...

Unless they were very close, a technology similar to ours, looking at the Sun, might only detect Jupiter. But it doesn't take much more to detect other planets as well, by looking at perturbations of Jupiter's orbit- something we're doing to detect multiple planets in other systems.

We're certainly detecting more multiple planet systems now. And we're certainly missing many planets. That's to be expected, and as the statistical base continues to develop, we have a better idea what the actual counts are likely to be.

These interesting speculations always fall over when they speculate that we might be able to communicate if only there is intelligent life there.... 'Intelligent life' is necessary, but not sufficient, for communication. No-one could accuse the ancient Egyptians, Greeks, Romans, or Victorian England of lacking intelligence, or even advanced technical capabilities, but you wouldn't have been able to talk to them. What is needed are technologically advanced life-forms that have mastered electronics....

isoparix wrote:What is needed are technologically advanced life-forms that have mastered electronics....

And an interest in communicating. We've only had electronics for less than a century, and we've already become a radio quiet planet, unlikely to be detected unless we actively choose to send signals into space.

Chris Peterson wrote:

isoparix wrote:
What is needed are technologically advanced life-forms that have mastered electronics....

And an interest in communicating. We've only had electronics for less than a century, and we've already become a radio quiet planet, unlikely to be detected unless we actively choose to send signals into space.

Radio waves never made it out of the ionosphere anyway.

We still broadcast TV; however, the aliens will now have to get a hold of a digital to analog converter box.

neufer wrote:Radio waves never made it out of the ionosphere anyway.

I think that comment requires some explanation. Unless you believe that the entire space program is a hoax, it's pretty obvious that radio waves do make it out of the ionosphere. And people have done calculations about the sort of antennas and receivers required to pick up our accidental emissions at large distances, and they're certainly possible.

We still broadcast TV; however, the aliens will now have to get a hold of a digital to analog converter box.

Our increasing radio quietness comes not from using less radio, but from technology that prevents much from making off the Earth at any substantial power.

Chris Peterson wrote:We're certainly detecting more multiple planet systems now. And we're certainly missing many planets. That's to be expected, and as the statistical base continues to develop, we have a better idea what the actual counts are likely to be.

absolutely. sci fi journalism and artistic blue sky views of putative new worlds are the populist face of science, but the facts suggest a more sober skepticism is necessary at this early stage in exoplanet astronomy. "earthlike" planets are also the most difficult to detect, and detection is strongly biased toward systems around nearby, low mass stars.

http://www.newscientist.com/article/dn2 ... r-all.html

one analysis that is possible with the existing statistical evidence, and conclusions from exoplanet research into the climate and atmosphere dependence on orbit and mass, is an updated look at the drake equation and the assumptions it makes about the relevant parameters to estimate. my sense is that there are perhaps only about a dozen "advanced" civilizations in our galaxy at present, which would make the average distance between them a few thousand parsecs.

Metaphorically one could imagine our 8 or 9 planets to be the same physical entity as existing in differing times.

Mercury – A rocky body

Venus – Hot and inhabitable Mercury with more solid matter and gas

Earth – A cooled down Venus with water

Mars – Earth after the water is gone, loss of moon and matter

Asteroid belt – A broken Mars

Jupiter – Asteroids back together, large accumulation of gas with moons

Saturn - Lost a little gas (Titan?), moons into rings

Uranus – After something hit Saturn got knocked on side, lost gas and most ring matter

Neptune – Regained some gas, strange density and size issues compared to Uranus

Pluto – Gas gone, back to a rocky body

Physically we see the planets are obviously there right now but know they will eventually evolve to something else given the predicted fate of our sun.

Creepily that while looking for other planet/sun systems we live in one with multiple planets that may, metaphysically, be imagined temporally.

Realistically how might our solar system appear if glimpsed through the illusion of time? Maybe we can look towards other suns and draw the right conclusion.

Definitely "LY" away.

Irrelevant...as GETTING THERE IS THE PROBLEM....it could be an exact copy of Earth...with no hindering intelligent live to us colonizing it...it is STILL....getting there....and once you get there...you still have to SLOW DOWN.

I think you will have to have Filling Stations along the way....service platforms for repairs, restocking supplies, etc...

And at current speeds, and even Nuclear produced speeds...it will take many, many, many generations to get there.

I don't really hold out that there is a convenient Worm Hole connecting us to that system, and we can get there in one day, or week.

But, hey 500 more years, and we might just find a way....look what we have done, in the last 114 years....

:---[===] *

New Scientist reports on new work that reviews the data from Gliese 832, the star alleged to have a whole tribe of exoplanets. It does seem remarkable that such an otherwise ordinary red dwarf should have not one, not two but SIX planets detectable from Earth, and it probably doesn't!

Gliese 382d and 382g are more likely to be perturbations in the star's light due to sunspots, while b, c, and e may be real, and on a and f, the article sayeth not.

It also attribute Fomelhaut b to a 'dust blob' and Alpha Centauri Bb to noise in the data.
http://www.newscientist.com/article/dn2 ... r-all.html

Tweedledee, thou shoulds't be living at this hour, to disabuse us of these over-imaginative 'discoveries'!
“Contrariwise, if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic.”

John

Double check your numbers, John. You've managed to flip your 3 and your 8 a couple of times.

Did that make it difficult for you to understand my post?

If i was dyslesic I's have an excuse, but I';, not! I'm jsy and bad typeist!
JOhn

No, but I do the same thing constantly and it's nice to know I'm not alone. I have to go over any numbers I type three times to make sure I typed them in the correct sequence.

So are WE actively broadcasting our presence to possible life-supporting exo-planets ?

geckzilla wrote:No, but I do the same thing constantly and it's nice to know I'm not alone. I have to go over any numbers I type three times to make sure I typed them in the correct sequence.

That's not as bad as going right along, thinking of the words as you type them, then discovering a few words 'in a row' are missing. Just what the hell are the fingers doing when that happens?