Why is the Sun / Kerbol so big (and so low density)?

[NERVAfan]

Most of the bodies in KSP are somewhere around 1/10 the size of their real-world analogues.

Sun radius = 696000 km, Sun/Kerbol radius = 261600 km

Mercury radius = 2440 km, Moho radius = 250 km

Venus radius = 6051 km, Eve radius = 700 km

Earth radius = 6371 km, Kerbin radius = 600 km

Moon radius = 1737 km, Mun radius = 200 km

Mars radius = 3390 km, Duna radius = 320 km

Jupiter radius = 69991 km, Jool radius = 6000 km

Eve and Mun are a bit bigger, Kerbin, Duna and Jool a bit smaller, but they're all pretty close to 1/10.... except the Sun/Kerbol, which is more than 1/3 the radius of the real-world Sun. Why is this?

[Superfluous J]

Because they wanted it to get eclipsed by Mun.

[Guest]

Because they wanted it to get eclipsed by Mun.

Shouldn't they have made it smaller then?

[Fr8monkey]

This is why the Kerbol system is not in scale...

http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.html

[Twreed87]

This is why the Kerbol system is not in scale...

http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.html

That's... not what he asked.

He asked why the Sun is the only thing that doesn't fit the general 1/10th scale, because the rest of the system largely is to scale.

[merendel]

He asked why the Sun is the only thing that doesn't fit the general 1/10th scale, because the rest of the system largely is to scale.

The planets are close to 1/10th, Kerbin's orbit is close to 1/10th, as observed Kerbol isnt. Guess what other measurement in the system isnt to that scale? Mun is significantly closer to kerbin than 1/10th would dictate. Mun is at 12,000km while the Moon is around 385,000 KM or so. They probably put Mun closer than it should be to make it easier to reach but because of the angles they had to make Kerbol bigger to make the proper eclipse work. If Mun was in a proper 1/10th scale orbit it would be out alot closer to where minus is, 38000km next to minmus's 47,000km

[NERVAfan]

But Mun could still eclipse Kerbol even if Kerbol was a point of light...

Is the idea that they wanted them to look the same size from Kerbin just as the Moon and Sun do on Earth?

(For that matter, why IS the Mun that close? Is it a relic from early versions of the game before they had good time warp?)

[aeTIos]

I indeed think it is the reason NERVAfan brought up. From Earth, the moon and the sun look pretty much the same size. So when Kerbol became an actual object (it used to be a point source with various special effects overlayed) I think they decided to make it appear as big as Mun.

[Superfluous J]

I can't tell if you're being pedantic or not, but the intent of the developers was to have Mun eclipse Sun in the same way that our Moon eclipses our Sun. If the Kerbin Sun was much smaller, that would not happen.

[NERVAfan]

Ah, OK, makes sense...

[Pecan]

Thank you - I'd never realised there more-or-less was a scale (apart from that dictated by physics, obviously).

That map by at joshworth.com is pretty fascinating too (if you like looking at 'empty' a lot, lol).

[HeadHunter67]

Kerbin's sun would have to be bigger, relatively speaking, than ours. They're closer to it, so the habitable zone is closer - which means the star is cooler... therefore relatively larger than our G2V star.

[ScallopPotato]

Apparently the scaled-downness started with Kerbin. The earliest versions of the game had no map view or time warp. In addition, LEO orbital velocity is about 3.14 times that of LKO orbital velocity. It takes about 9-10 km of dV to reach LEO, which is about 3 times what is needed to reach LKO with Ferram Aerospace and twice that of stock. However, reaching LEO with stock aerodynamics would've been even higher, perhaps 11-12+ km of dV. Remember that the atmosphere of early KSP was one consistent block that ended at around 32 km, although I'm not sure what the density was.

I could go into more about what an early LEO in KSP would look like, but it'd be like creating a sun-diving rocket out of the early parts just to reach orbit. People have done this, but it's ludicrous.

If I can find out how to make youtube videos of KSP, I'll try to make a rocket in RSS that uses early KSP parts and features. FOR THE CHALLENGE

In addition, there are some technical aspects. The surface area of Kerbin is 4.52×10^6 km. The surface area of Earth is 5.1×10^8 km. That's two more orders of magnitude of surfaces that has to be created, stored, and rendered. And the same scaling up would apply to any other bodies, too.

tl;dr: If Kerbin was the size of Earth, you'd need a Kerbol-diving rocket just to reach orbit using the early parts and no map view. In addition, each planet's textures would eat up so much RAM it wouldn't even be funny.