Making Tracks on Mars

The narrator says Mars won't line up this close to Earth for another two years. The correct positioning has nothing to do with proximity. The alignment needed is for Mars to be 44 degrees ahead of Earth. Probes are launched into orbit around the Sun and coast outward to the orbit of Mars. They reach the orbit of Mars at the same time as Mars in its orbit. It is called a Hohmann Transfer Orbit and is the only way we can send probes to other planets since they cannot carry enough fuel to fly under power.

It is that positioning of of the planets that occurs About every two years.