Question

Q C A minimum-energy transfer orbit to an outer planet consists of putting a spacecraft on an elliptical trajectory with the departure planet corresponding to the perihelion of the ellipse, or the closest point to the Sun, and the arrival planet at the aphelion, or the farthest point from the Sun. (b) Can such an orbit be undertaken at any time? Explain.

Answer 1

No, because we only can land on mar when it's at an appropriate position so that immediately after 516 days, the mar is at the opposite position from the initial position of the earth.

What is the minimum energy?

The minimal kinetic energy required for a pair of moving particles to collide in order for a particle to be produced is known as the threshold energy in particle physics. The threshold energy is always higher than or on par with the desired particle's rest energy.