There are a few ways to divide the Earth into equal halves, depending on what you're thinking about:

* The Equator: This imaginary line circles the Earth at 0 degrees latitude, dividing it into the Northern Hemisphere and the Southern Hemisphere.

* The Prime Meridian: This imaginary line runs from the North Pole to the South Pole, passing through Greenwich, England. It divides the Earth into the Eastern Hemisphere and the Western Hemisphere.

* The International Date Line: This imaginary line runs mostly along the 180th meridian. It's used to determine which day it is in different parts of the world, dividing the Earth into two halves based on time zones.

So, the answer really depends on what kind of "equal halves" you're looking for!