Kerbin atmosphere size

[asmi]

Hello all,

I've got a question that bugged me for few days now - why Kerbin's atmosphere is so small? If I understand the physics of it right, atmosphere size is proportional to the celestial's mass. Kerbin's mass is just a bit smaller than that of the Earth, so the atmosphere have to be similar, hasn't it?

I'm looking forward for your opinions on the subject.

[Demobot]

It's my understanding that Kerbin has substantially less mass than Earth. If the KSP Wiki is accurate, Kerbin has a mass of ~5.3*10^22 kg, whereas Earth has a mass of ~6*10^24 kg. This would mean Kerbin's mass is less than 1% of Earth's.

[chaos_forge]

Kerbin has the same surface gravity, but NOT the same mass. It weighs substantially (at least a few orders of magnitude) less than the Earth, but is either made of much denser materials or exists in a universe where the gravitational constant is stronger. Take your pick. Anyways the bottom line is that surface gravity is not a perfect indicator of mass. Jool and Laythe both have the same surface gravity (0.8g).

[lajoswinkler]

Kerbin's atmosphere is not small at all. It's actually extremely thick. Kerbin's radius is 600 km, whereas Earth's is 6378.1 km. Kerbin is 10.63 times smaller.

KSP does not model termosphere and ionosphere. Analogue to Kerbin's 69km would be probably Earth's 150 km, height at which most objects can make one orbit without decaying down.

If Kerbin's atmosphere was to scale, it would be possible to make one orbit at 14.1 km.

[leax256]

if an apple represented earth the skin is the atmosphere