And as long as you satisfy the equation,

等式一旦成立
I don't care if the thing you're spinning is a satellite or a potato,

不管是卫星还是马铃薯都可以
because the mass of the object drops out.

因为物体的质量消去了
So, the condition for orbit is

轨道的状态
independent of the object orbiting, again,

与在轨道上运动的物体本身无关
due to this cancellation of the mass on both sides.

因为两边的质量都消去了
All right, so this is all we can get out of Newton's Laws.

这是我们从牛顿定律得到的
So, let's go back to Kepler.

回到开普勒
Is the orbit possible?

轨道运动是否合理
Well, if you say an ellipse--

如果在椭圆中
a circle is a special case of the ellipse,

圆是椭圆的一个特殊情况
you have shown circular orbits are possible.

你们已经知道圆周运动是可能的