On what dates of the year are the sun's ray's tangent at the artic and antarctic circles?

Answer 1

Whoaaaa...
NOT at the equinoxes--

the SOLSTICES.

At the solstice, the sun's direct rays hit on either the tropic of cancer or capricorn. The arctic or antarctic circle would be 90 degrees off either of those lines. At the equinoxes, the sun is directly over the equator, and the direct rays are tangent at the poles.

Your answer: On around June 22 (N Hemisphere summer solstice), direct rays are tangent to the antarctic circle. On around Dec. 22, (N Hemisphere winter solstice), direct rays are tangent to the arctic circle.

Answer 2

Vernal and Autumal Equinoxes. The exact date changes from year to year. This year it is March 20, and September 23.

Answer 3

At the equinox. First days of Spring and Fall.

Answer 4

How would I know - ask an Eskimo.