At noon on the vernal equinox, vertical rays strike the Earth along the equator.

Here's why:

* Vernal Equinox: This is the day when the sun's rays are directly overhead at the equator.

* Equator: This is an imaginary line that circles the Earth at 0 degrees latitude.

Therefore, at noon on the vernal equinox, the sun is directly above the equator, resulting in vertical rays hitting the Earth's surface at this location.