The rays strike Earth at their northernmost and southernmost positions during the solstices.

* Summer solstice: The sun's rays hit the Earth at the most northern point, resulting in the longest day of the year in the Northern Hemisphere.

* Winter solstice: The sun's rays hit the Earth at the most southern point, resulting in the shortest day of the year in the Northern Hemisphere.

It's important to note that these solstices occur at different times of the year in the Northern and Southern Hemispheres due to the tilt of the Earth's axis.