Whether you’re watching the aurora borealis in the north or the aurora australis in the south, you’re seeing the same spectacle, caused by the solar wind hitting the Earth's magnetic field and producing currents of ions. Those ions collide with gas atoms in the atmosphere, creating extra energy that's released as photons. The result? Beautiful, cascading bands of light in the sky. #HostilePlanet is now streaming on Disney . | National Geographic Adventure