Here's why:

* The Arctic Circle is located at 66.56° North latitude.

* The Tropic of Capricorn is located at 23.44° South latitude.

* The difference in latitude between the two is 66.56° + 23.44° = 90°.

* The Earth's circumference is approximately 24,901 miles.

* Therefore, the distance between the Arctic Circle and the Tropic of Capricorn is roughly 90/360 * 24,901 miles = 9,000 miles.

It's important to note that this is an approximate distance because:

* The Earth is not a perfect sphere.

* The distance is measured along a great circle, which is the shortest distance between two points on a sphere.

* The actual distance traveled between the two circles would depend on the specific route taken.