So, even if you’re standing in the Southern Hemisphere, your compass needle will always point north. Beyond the outer edges of the magnetosphere, however, things get a little more complicated.

Perhaps the easiest thing to identify—and misuse—on every paper chart is the compass rose. It will typically display with an outer and inner ring. The outer ring will have a star at the top indicating ...

And pushing a collision scenario further into the past, to hide this evidence, runs into the problem of the ages of stars: the outer ring of stars is quite blue in color, suggesting a younger age ...

This is the crustal magnetic field, Espley said — rocks on the outer crust that still hold evidence of the planet's old geodynamo. Of all the planets in the solar system, a compass is most ...