Celestia Forums

Just found this article at NASA

http://www.nasa.gov/vision/universe/sta ... anets.html

I contacted one of the authors to see if I can get some more in depth info. Thought this might come in handy for all of you system creators out there.

Pure carbon monoxide planets? Never heard of that possibility elsewhere.

A pure hydrogen planet of one Earth mass? That's not likely.

The author contacted me and provided a link to the paper.

http://xxx.lanl.gov/PS_cache/arxiv/pdf/ ... 2895v1.pdf

Ah, thank you. Interesting read.

Hmm, I see that they mention planets beyond the water-ice line. I expect that is a planet is far enough from its star, it could retain a lot of hydrogen or helium even at one Earth mass. You could call such a world a microjovian perhaps- or a superTitan....

I made an excel spreadsheet that uses the formulae in this paper for terrestrial planets (they don't really detail their formulae for gas giants). It'll let you tweak the numbers (what percent Ice/Rock or Rock/Iron, and mass) and it'll give you the planet's circumfrence, gravity, radius and even the distance to the horizon from the height of 2 meters from the surface (the latter formula from Stephen's Gillett's "World Building")

I have another spread sheet that allows you to input some data and get the optimal goldilock's zone location for a planet around a given main sequence star, the tides of the stars (can have up to 3 stars), how large the stars will appear in the sky from said planet, how intense the light from your star will be at a given distance, and other data as well. (formulae from Stephen's Gillett's "World Building" and various scientific papers on finding the goldilocks zone and habitable planets.)


I'd be glad to upload these for the community, but I have no idea how to go about doing so. If you're interested, just let me know how to do it! =)

I can host it from my site if you want to email it to me.

I'd be glad to. Your profile doesn't have your email address though. I'll clean it up for presentation in the meantime. Oh, and I'm not a mathmatician by a long shot, so if anyone finds any problems with it, please let me know so I can corrrect them for my own sake.

Here is Todd's file

http://www.clanmoran.net/celestia/site/files/Celestia_Add-ons3/Slartibartfast's_World_Builder/Todd_St._Pe's_Worldbuilder_spreadsheets.xls

I just emailed Buggs a new and improved version of the spreadsheet that includes the edges of the Habitable Zone. These formulae were detailed in papers by Dr. Jim Kasting... an all around swell guy. Now this aspect of the sheet ought to be as cutting edge as it can get... at the moment.