I'm heavily ignorant when it comes to mathematics and just science in general, but I have thought of four habitable planets, all of them revolving around a K-type sun. They're all colonized by humans, and i'm trying to come up with the geography and size of each planet. I would love it if anyone could look at what I have written and correct me, as well as fill in blanks on what they think my planets would look like or have.
I'll write them in order from closest to the sun to farthest. Currently I have not thought of moons.
Labita: In size, it's small, the smallest planet currently. I'd say a mass and radius directly similar to Earth. Labita's surface is 64% water.
Vir: Slightly bigger than Labita. It has a surface that's 72% water.
Mena: Surface is 60% water. smaller than Vir, but bigger than Labita.
Kaldreer: A superhabitable (large with heavy gravity) planet. I'd say it's surface has at most 77% water. Warm, and a thicker atmosphere.
My first concern is the orbit. I would say they would mimic our own solar system's orbit, but I don't know how far away they would all have to be to not collide, and if the distance they'll be from the sun is safe enough.
My second concern is their size. I know I definitely made some mistakes, but I know for certain that I want Labita to be the smallest, then Mena, then Vire, then Kaldreer. I want Kaldreer to be significantly bigger than Labita, but not too big that it would unsafe for human life. How big and how small can I make Kaldreer and Labita before it's unsafe? (Update: would it be too far of a stretch to propose the idea that Labita and Kaldreer would orbit around eachother instead?)
Thanks to anyone who decides to read and help me.