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 Post subject: Re: TRAPPIST-1
PostPosted: Tue, 04-07-17, 19:08 GMT 
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Selden wrote:
Celestia supports OverlayTextures used as "limits of knowledge" in addition to multiple AltSurface declarations. Hopefully CelestiaSci does, too. Either of those could be used to make simultaneously available both the best scientific and the best imaginative surface feature maps.

FWIW, I've stumbled across several problems in Celestia v1.6.1 when trying to use VirtualTextures as OverlayTextures, including black regions and/or distorted tiles when some tiles are omitted from some of the VT levels. It'd be nice to know if those kinds of bugs have been fixed in CelestiaSci.


Selden,

when I referred to the "familiar key shortcut" above, I meant of course excacly the switching between normal textures and limit-of-knowledge ones. I did not yet check the code with respect to a bug here. But anyway, it's easy to write some apprpriate code to accomplish what I suggested above.

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 Post subject: Re: TRAPPIST-1
PostPosted: Sun, 09-07-17, 7:07 GMT 
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@sjohn

Everything is possible. But...

Bear in mind a bluish tinted oxygen atmosphere would require a permanent oxygen "supplier" (bacteria, algae,...).
Otherwise oxygene will be bound ( in water - if exist, iron oxides,...).
That's why i made a little note some posts before (turquoise color of the ocean)...

Considering the "low" age of star and planets i think that a photosynthetic conversion (caused by bacteria) is rather improbable.

Only infrared radiation. Which is too weak to enforce deformation and new formation of molecular chains.
On earth, for example, this was very important and necessary to build first organic cell components (Ribosomes, mitochondria,...).
But this was forced by UV-radiation!

I guess a hydrogen-based atmosphere is more probable.
Furthermore, regarding the strong density of the planets, ferrous, reddish colored oceans.
provided that liquid water exist on their surfaces...

Michael


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 Post subject: Re: TRAPPIST-1
PostPosted: Thu, 13-07-17, 15:23 GMT 
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MiR, thanks for your information and help!

I made some changes: I made the atmosphere blue, and the oceans are red now.

Is it realistic?

Would you be so kind to help me with these?

Questions:

- are there clouds?
- what kind of clouds are there, thick or thin?
- what is the color of the clouds?
- what is the color of the ice?

Planet d:

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Planet e:

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Planet f:

Attachment:
TRAPPIST-1f-red.png
TRAPPIST-1f-red.png [ 1.66 MiB | Viewed 1004 times ]


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 Post subject: Re: TRAPPIST-1
PostPosted: Thu, 13-07-17, 20:41 GMT 
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Or maybe a less intense blue atmosphere is better?

Attachment:
planet d.png
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Attachment:
planet e.png
planet e.png [ 634.57 KiB | Viewed 992 times ]


Attachment:
planet f.png
planet f.png [ 1.68 MiB | Viewed 992 times ]


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 Post subject: Re: TRAPPIST-1
PostPosted: Thu, 13-07-17, 20:46 GMT 
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These are the potential colors as I understand:

Attachment:
colors.jpg
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 Post subject: Re: TRAPPIST-1
PostPosted: Fri, 14-07-17, 7:29 GMT 
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The intensive search for habitable zones and life on exoplanets around ultracool M-type dwarfs (TRAPPIST-1,...) has to face quite some pessimistic new findings from TWO teams of scientists led by researchers from the Harvard-Smithsonian Center for Astrophysics!

Here is a more popular-style short summary of both findings
(http://bgr.com/2017/07/13/trappist-1-planets-life/)
along with the respective references to the scholarly papers:

  • Team 1 discovered that, despite the star at its center being relatively cool in comparison to most, it’s still putting out lots and lots of ultraviolet radiation. That radiation has the potential to degrade and in some cases destroy the atmospheres of the planets nearby. The planets in the system are much closer to their star than we on Earth are to the Sun, and without a healthy atmosphere, the idea of life on any of the planets is laughable.
    https://www.cambridge.org/core/journals ... FF4EB66F52

  • Research team 2 has independently proposed that solar wind would be another devastating force preventing life from existing on the TRAPPIST-1 planets. Our own Sun produces a solar wind, but we’re far enough away — and benefit from a protective magnetic field around our planet — that we are saved from its wrath. The exoplanets, which are in much closer proximity to their star, would have a much more difficult time maintaining an atmosphere.
    http://lanl.arxiv.org/abs/1706.04617

Fridger

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 Post subject: Re: TRAPPIST-1
PostPosted: Fri, 14-07-17, 20:26 GMT 
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Thanks for the information! I'm interested in the aesthetics of exoplanets, so I really like inhabitable ones too...

Is there any scientific work or book describing potential exoplanet colors, atmospheres, visibility, water, ice etc..?

It seems to me that a lot of knowledge has been gathered in the last two decades about exoplanets but I would need a more "practical" guide...a little more speculation about the real physical conditions on these planets (as it would be experienced by a human being exploring there).


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 Post subject: Re: TRAPPIST-1
PostPosted: Fri, 14-07-17, 21:53 GMT 
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sjohn wrote:
Is there any scientific work or book describing potential exoplanet colors, atmospheres, visibility, water, ice etc..?

Yes, but the results are based on model-building associated with observational input: For example,
the atmospheres of orbiting Earth-sized planets are observationally accessible / constrained via transmission spectroscopy when the planets pass in front of these stars. This way it was e.g. established with a big margin that the TRAPPIST-1 planets b and c cannot have a (cloud-free) H2 - dominated atmosphere. See e.g. https://arxiv.org/pdf/1606.01103.pdf

The more questions one asks simulataneously, the more complex the modelling becomes and dedicated computer work is required before reliable parametric constraints (& uncertainties) can be obtained.

I suppose you know already, how the planetary densities can be determined from observations during planetary transitions.

I am currently thinking along such lines with regard to a possible embedding of respective simulations into celestia.Sci...

Fridger

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 Post subject: Re: TRAPPIST-1
PostPosted: Sat, 15-07-17, 15:50 GMT 
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Fridger wrote
Quote:
I am currently thinking along such lines with regard to a possible embedding of respective simulations into celestia.Sci...

That would be fantastic!

My only fear is that procedural textures are not at all realistic.

For example Space Engine seems to be a fancy video game (at least to me), not a realistic space simulation.

I think graphic simulations should be based on real patterns and real textures.

The human brain can tell the difference between simulated procedural and transformed/manipulated real textures...the latter seem much more real in my opinion.


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 Post subject: Re: TRAPPIST-1
PostPosted: Sat, 15-07-17, 18:18 GMT 
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sjohn wrote:
Fridger wrote
Quote:
I am currently thinking along such lines with regard to a possible embedding of respective simulations into celestia.Sci...

That would be fantastic!

My only fear is that procedural textures are not at all realistic.
...

Given so many unknowns in the game, a systematic, albeit less realistic approach to the TRAPPIST-1 planet appearances is much preferrable. Scientists do certainly agree here...The really important aspect is that the modelling code is written as flexible as possible, then allowing for adaptation to incoming new observational results!

Fridger

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 Post subject: Re: TRAPPIST-1
PostPosted: Sat, 02-09-17, 20:31 GMT 
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TEMPORAL EVOLUTION OF THE HIGH-ENERGY IRRADIATION AND WATER CONTENT OF
TRAPPIST-1 EXOPLANETS

https://arxiv.org/pdf/1708.09484.pdf


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 Post subject: Re: TRAPPIST-1
PostPosted: Sun, 03-09-17, 18:06 GMT 
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sjohn wrote:
TEMPORAL EVOLUTION OF THE HIGH-ENERGY IRRADIATION AND WATER CONTENT OF
TRAPPIST-1 EXOPLANETS

https://arxiv.org/pdf/1708.09484.pdf


Thanks sjohn for the link to this paper! Exploring specifically the implications of the Lyman-alpha (aka Ly-α ) line ( 1215.67 Å) and generally of ultraviolet (UV) transit spectroscopy as powerful pointers towards signatures of atmospheric escape from exoplanets is a very interesting new approach for gaining better knowledge about the REAL atmospheric compositions of EXOs.

For non-scientists, visible light covers the range from 4000 to 8000 Å.

Fridger

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 Post subject: Re: TRAPPIST-1
PostPosted: Thu, 26-10-17, 10:34 GMT 
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https://arxiv.org/abs/1710.08761

Magma oceans and enhanced volcanism on TRAPPIST-1 planets due to induction heating

:mrgreen:


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 Post subject: Re: TRAPPIST-1
PostPosted: Fri, 17-11-17, 21:08 GMT 
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https://arxiv.org/abs/1711.05739

PLANET-PLANET OCCULTATIONS IN TRAPPIST-1 AND OTHER EXOPLANET SYSTEMS

update ;)

[code]

:shock: WTF ??????


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 Post subject: Re: TRAPPIST-1
PostPosted: Wed, 22-11-17, 10:14 GMT 
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Thanks symaski62 for your valuable help!!

Fridger

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