The orbit of a stable planet around a star like the Sun is always in the shape of?

Question

Please help if you can.... ten points to first right answer

Answer 1

An ellipse, of which a circle is a special case.

Answer 2

The textbook answer is "an ellipse". But the fact is, that is only an approximation -- generally a very good approximation, but not good enough for rocket science. The actual orbit is a path which meanders around near an ellipse, and the ellipse also wanders around quite a bit, changing its shape and orientation.

If there are any other masses in the system (and there always are other masses), the orbit is the result of the gravitational attraction among all the objects. In order to compute the orbit, you need to do a numerical integration of the gravity forces. For example, in our solar system, the masses of the 20 largest asteroids has a significant effect on the orbit of Mars. In order to send a probe from Earth to Mars, these effects must be taken into account.

Answer 3

Ellipse.

Discovered by Johann Kepler. Proven by Sir Issac Newton.

A perfect circle is possible if the sun and the planet are both perfect spheres and there is nothing else in the rest of the universe. That obviously is not the case, so ellipses it is.

Answer 4

Yes, an ellipse is the correct answer.

Answer 5

An ellipse.

Answer 6

A circle.