How many months after earth’s perihelion position does earth’s aphelion position occur?

The Earth's aphelion position occurs about six months after the earth's perihelion position.The earth's perihelion position is the point in its orbit when it is nearest to the sun. The earth's aphelion position is the point in its orbit when it is the furthest away from the sun.  The earth is closest to the sun around 3 January each year and it is farthest from the sun around 4 July every year.  It is winter in the northern hemisphere when the earth is closest to the sun, and it is summer in the northern hemisphere when the earth is furthest away from the sun. The seasons in the southern hemisphere are opposite to those of the northern hemisphere.

Which one is the underlined word?

Don’t use up to much of them it leads to pollution