Early in the history of our solar system, something mysteriously knocked Earth slightly off its axis. So today we tilt at 23.5 degrees. But what would happen if we tilted even more? What if Earth ...

Earth's obliquity is 23.4 degrees, but over history it has varied between 22.1 and 24.5 degrees approximately every 40,000 years. Precession refers to the "wobble" of this rotational axis.

The vernal equinox, which occurs at the start of astronomical spring, is when the sun's rays equally shine on both of the ...

Illinois is located about 40 degrees north of the equator ... The equinox is the moment when the Earth's axis is tilted neither toward nor away from the sun, resulting in a "nearly" equal amount ...