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Challenge: Planet With the Highest Earth Similarity Index
Destructor1701Date: Friday, 17.01.2014, 22:15 | Message # 16
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I'm not submitting this to the challenge, since it's a relatively low ESI... but I am asking: Why is this planet a low ESI? It's basically a twin of the early Earth. I don't get it.


Attachments: 1282667.jpg (177.1 Kb)







Edited by Destructor1701 - Friday, 17.01.2014, 22:17
 
Billy_MayesDate: Friday, 17.01.2014, 22:47 | Message # 17
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I'd say the temperature and the high number of moons.




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HarbingerDawnDate: Friday, 17.01.2014, 23:40 | Message # 18
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Quote Billy_Mayes ()
temperature

Yes

Quote Billy_Mayes ()
number of moons

No





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VassichuDate: Saturday, 18.01.2014, 02:52 | Message # 19
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There is also no moon, but I think it being tidally locked kinda fixed the problems associated with not having a moon.
 
Fireinthehole-Date: Saturday, 18.01.2014, 04:13 | Message # 20
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The axial tilt is pretty high, maybe that's the reason?




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Destructor1701Date: Saturday, 18.01.2014, 21:15 | Message # 21
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42 degrees off vertical, nearly twice our own tilt - I suppose it would indeed lead to very drastic seasonal changes.

Quote Vassichu ()
There is also no moon, but I think it being tidally locked kinda fixed the problems associated with not having a moon.


This is a moon, a 2700km moon at 50000km sma, as well as several small rocks in closer orbit, and the planet isn't tidally locked, it has a 15 hour day, and a nearly precise Earth-year.

I hadn't noticed how hot it was there, though - 64 degrees C on average? Ouch. Liveable, but not for long. Isn't that rather similar to conditions on Earth a billion years ago?

I still think it deserves a slightly higher ESI, if the engine's criteria are posted somewhere on the forum, I missed them, and not for lack of searching.

Edit:

From Wikipedia:
Quote
The ESI is a function of the planet's radius, density, escape velocity, and surface temperature.


So, by my shoddy and certainly mistaken calculations, the ESI should be 0.953 for this planet. But I didn't understand some of the symbols in the formula, and probably got the maths wrong at some point. Man, my brain is tired and stupid after that.







Edited by Destructor1701 - Saturday, 18.01.2014, 22:20
 
Fireinthehole-Date: Saturday, 18.01.2014, 21:31 | Message # 22
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Quote Destructor1701 ()
42 degrees off vertical, nearly twice our own tilt - I suppose it would indeed lead to very drastic seasonal changes.

32 degrees wink





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Destructor1701Date: Saturday, 18.01.2014, 22:21 | Message # 23
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Quote me
Man, my brain is tired and stupid after that.


Anyway, I've hijacked this thread enough, back to the challenge!







Edited by Destructor1701 - Saturday, 18.01.2014, 22:22
 
Omicron314Date: Thursday, 30.01.2014, 21:31 | Message # 24
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Found this one as I was going through all inhabited planets within 15 parsecs of Earth.



ESI of 0.970, despite the 18 bar atmosphere and tidal locking. I think SE might be doing something a bit weird when it comes to calculating these things.
 
SpaceEngineerDate: Thursday, 30.01.2014, 22:22 | Message # 25
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Atmosphere pressure and rotation rate are not used in computing the ESI: http://en.wikipedia.org/wiki/Earth_Similarity_Index
Just think of exoplanets: we can't obtain atmosphere pressure and rotation rate from observations. So it have no sense to use them in the ESI.





 
AerospacefagDate: Thursday, 06.03.2014, 22:07 | Message # 26
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I was trying to find more Earth-like worlds in vicinity of Earth in the new version, but the problem is, it's really hard to find any planets that have ESI close to or over 0.95 even with star browser. It doesn't help that Earth itself has ESI equal to 0.997

I'm not covering all of the space around 50 parsecs from Earth, just some parts of it, in a randomly distributed spheres about 60 parsec in diameter. Because star searching mechanism is only capable of finding stars in 10 parsec radius, I had to use some math for http://en.wikipedia.org/wiki/Sphere_packing technique to cover the broader radius.

However, during these times, many Earth-like worlds are here, and even near Sun-like stars. Here are the two particular examples.

Earth-like world with rings and no terrestrial life, quite a young one, but the star system is very similar to Earth.


A water world, but not Oceania, ESI exactly 0.95, and the star system is quite classical one too.


This is a similar planet, but it's somehow illuminated from both sides, which creates quite interesting effect.


Edited by Aerospacefag - Saturday, 28.06.2014, 15:57
 
AerospacefagDate: Thursday, 06.03.2014, 22:16 | Message # 27
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And also, a number of moons (1, one, uno) is almost impossible to repeat because SE 0.971 rarely even bothers to add a big moon to the terrestrial planet, not to say anything about planets with high ESI.

Here's also one interesting example. It's really beautiful world, and it has exactly one "moon", only a few kilometers in diameter. I made my current wallpaper from it.

Quote

Place "Terra ESI 0.88 2Hot 26.8pc Positive"
{
Body "HIP 107070 6"
Parent "HIP 107070"
Pos (3.230132651155585e-010, 9.936507454517962e-012, 5.651269037692912e-010)
Rot (0.9521400746407461, 0.0009012767669906721, 0.2867790766297325, -0.1057649619236053)
Date "2012.04.15 14:16:25.53"
Vel 6.5100286e-011
Mode 1
}

Attachments: 0500377.jpg (366.4 Kb) · 5540549.jpg (245.1 Kb)
 
Destructor1701Date: Saturday, 08.03.2014, 02:23 | Message # 28
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I was just re-reading this thread today, and something Space Engineer said:

Quote SpaceEngineer ()
Just think of exoplanets: we can't obtain atmosphere pressure and rotation rate from observations.


...got me thinking.

This could be a major obstacle to the eventual decision of what star system to send our first interstellar probes to...

...and then I saw this article via Reddit:

http://www.universetoday.com/110038....ability

An amazing coincidence, and a flipping awesome application of science.

EDIT:

And in relation to rotation, I just remembered this amazing observation:

http://www.nasa.gov/mission....ce.html

It got me thinking that, when we have telescopes capable of routinely observing the reflected light from exoplanets (I'm not sure if the JWST will even remotely be capable of this) - which will probably not be soon, that different surface features will cause the brightness on different parts of the spectrum to vary. The variation rate will be fixed for landscapes and oceans, and will create a repeating pattern that can be interpreted as the rotation rate.

EDIT: Actually, this is off-topic here, isn't it? Sorry - I should have posted it in the Exo-planets thread.







Edited by Destructor1701 - Saturday, 08.03.2014, 02:32
 
Sidney600Date: Thursday, 27.03.2014, 16:57 | Message # 29
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I managed to find this planet with an ESI of 0.971.
Star is: RS 0-8-3893383-365-28-8-8926744-11
4th planet



Edit* I managed to find one with an even higher ESI, at 0.981 !

Place "ESI 0.981 Terra"
{
Body "RS 0-4-948-39-25437-8-7653276-67 4"
Parent "RS 0-4-948-39-25437-8-7653276-67"
Pos (-3.789189767619723e-010, -5.85459553070506e-010, 4.190292648455218e-010)
Rot (0.8136883993396631, 0.2915150513049535, -0.3968628845708052, 0.3089174881628867)
Date "2065.03.07 17:23:11.23"
Vel 8.1358961e-011
Mode 1
}

**Edit!

Here is another one i found which beats the one above with an ESI of 0.982


But i guess they don't count because they aren't in the milky way. :P

***Edit!
Ok here we go, found one in the Milky Way with an amazing ESI of 0.985!! biggrin

RS 8409-1796-8-4737396-2 3.11

6414.09.18 : This is the time for it to be ESI 0.985



Edited by Sidney600 - Monday, 31.03.2014, 15:52
 
Zaddy23Date: Sunday, 20.07.2014, 23:39 | Message # 30
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Here's my entry, I don't expect to win but for it's ESI it is pretty odd.

Cinematic screenshot.


RS 8409-1357-9-57584866-75 BB1

Proposed name: ignis et glaciem (fire & ice in latin)
Temperate terra orbiting a brown dwarf I have decided to name Calidum-scelerisque (hot chocolate in latin) in a binary brown dwarf system which orbits a red dwarf.

Gravity: 0.6g

Atmo pressure: 4.9

Temp: 284K avg. (10c)

Orbit period: 2.5 days

Day period: Tidally locked

Axial tilt: Negligible (not that surprising)

Magnetosphere: Yes

Liquid water: Yes (estimate)

Life: No (I wonder why... unsure )

ESI: ~0.8 ( surprised )

Moon system:


A bunch of asteroid moons, no big selenas to stabilise the system sadly sad
Notes:
For 1/2 of it's 2 day orbit the dark side is lit by the red dwarf in the distance.
Awesome place to study brown dwarves from.
I faff'n love this game yahoo

Attachments: 9571683.jpg (418.2 Kb) · 8784139.jpg (371.5 Kb)





Along with fezes and bowties, brown dwarves are cool.

Edited by Zaddy23 - Friday, 08.08.2014, 01:01
 
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