If Electromagnetic Radiation can travel through the vacuum of space then it can travel without a medium, but shouldn’t this be imposable? Or is it true that Electromagnetic Radiation uses the medium of existing magnetic fields, such as earths, distorting these fields much like sound waves do to air? And if so how can this have a direction of travel?

Electromagnetic waves travel through a vacuum and any other physical medium slows or stops their progression. They do not use existing magnetic fields as a medium, though they do interact with them.

An electromagnetic wave is nothing more than a propagation of a changing electric and magnetic field. These fields are always perpendicular to each other and travel in the direction of E x B, where E and B are vectors indicating the direction of these fields.

It’s because these are electric and magnetic fields. These fields are just regions where forces are exerted on charged particles; they are not made of particles themselves in the same way that sound waves are made from air molecules.

- By Wilbur Billet