Question

what evidence do we have that earth has a magnetic field surrounding the planet?

Explanation:

Key evidence for Earth's magnetic field includes: 1) Compass needles aligning with magnetic north-south, 2) The aurora borealis/australis (charged particles from the sun interacting with the magnetic field), 3) Magnetic minerals in rocks preserving field direction (paleomagnetism), and 4) The magnetosphere deflecting harmful solar wind.

Answer:

Compass alignment, auroras, paleomagnetism, and magnetosphere protection are evidence of Earth's magnetic field.