World builders - does this look right to you?

[Ray McCarthy]

I thought I had mentioned the 8 Atm. was an issue (apart from sounding unlikely), but it might have been in a message. But if it's 8 Atm. at sea level what is it at 7,000m or 10,000m altitude? A smaller planet than Earth might have higher mountains, and a larger one lower mountains, but it depends on volcanism and plate tectonics too. I'd have had thought you'd need an enormous planet to feasibly have 8 atm. But I'm not sure.

I forget where I studied effects of Jupiter on "incoming". I must have a go at some physics software. I'd like to build an entire Starship Science/Navigation program. Feed in observations and it models Solar Systems. Then you can create different navigation scenarios from least energy Transport (very slow) to high power constant acceleration. I've always wanted to make a fake spaceship bridge in the attic. I have loads of screens and computers not in use any more. I must have a look at some of the free astronomy planetarium programs and see can I import their data, or how to use Neutron Stars for navigation of the "jump drive" ...

I had a look at Kerbal Space Program (KSP) and it has serious flaws and limitations in its physics engine that renders it useless.

 

[Venusian Broon]

I've always wanted to make a fake spaceship bridge in the attic. I have loads of screens and computers not in use any more. I must have a look at some of the free astronomy planetarium programs and see can I import their data, or how to use Neutron Stars for navigation of the "jump drive" ...

I had a look at Kerbal Space Program (KSP) and it has serious flaws and limitations in its physics engine that renders it useless.

That would be seriously cool. For a mathematics/physics nerd like me

Must be reasonably 'easy' - c'mon Nasa plotted out the Voyager course with multiple slingshots on computers that alarm clocks today would scoff at. Getting nice graphics is another thing though!

 

[Ray McCarthy]

Actually the graphics is a separate program and reasonably easy, I've done a lot of harder graphics, both on DOS, Microcontroller with graphic LCD and Windows.
I need to finish the WIP though.

 

[Ray McCarthy]

Hot young Star giving birth (Their headline!)
http://www.theregister.co.uk/2014/11/07/bullseye_boffins_spot_baby_planets_in_the_eye_of_taurus/

 

[Mirannan]

Start with writing what you want for the planets (existing life, visiting Starship people, events etc). Then that will help you pick the size of planet and star.
You'll want maybe 5 to 12 planets per system, some Gas Giants.
Personally I suspect more than one inhabitable planet per star would be very rare:
two = extremely rare. But Galaxy a big place
Three = possible, maybe. I expect vanishingly rare.
Four and more probably impossible because orbits would be too close

To the last, I agree. But with one caveat; if the habitable worlds are actually moons of a jovian or superjovian which is in the Goldilocks zone, then there could be quite a few of them. In such a case, habitable worlds in the Trojan positions of the superjovian would also be possible; but that is stretching probability a little too much, perhaps.

I suspect two habitable worlds might be fairly common. After all, if Mars was a bit bigger it would probably be habitable.

 

[Ray McCarthy]

Venus, has wrong atmosphere. It and Mars are inside inner and outer edge of our Star's Goldilocks zone. At edges the planet type is much more fussy. Certainly there ought to be twos, threes and maybe fours. But progressively incredibly more rare. But in a story the very rare case is there BECAUSE it's rare!
I did mean two extremely rare compared to one. There could be millions of Stars with two worlds with life. Currently we have a sample of one system!

I just hope the bears are on a long walk and found some honey.