it's all math. I'd suggest you to go to your high school and borrow the alg. 2 textbooks. they're really useful for stuff like this, but i'll try to explain.robodude wrote:So my only question is this:
How do you find the semi-major axis if only given the perihelion, aphelion, or major axis?
so the equation for an ellipse is
x^2/a +y^2/b = 1
so a is your semimajor axis, and b is 1/2 your minor axis
there is a "c" which is the distance from the center to your foci. using kepler's laws, you know that the sun is one of the foci in the solar system.
so another equation is a^2+b^2=c^2. You can determine your A, B, or C values using this.
sorry i'm really bad at explaining, but an algebra II textbook would help lots for this type of stuff.