As the Northern Hemisphere welcomes spring today, the Southern Hemisphere is marked with the first day of autumn.

The winter solstice falls between Dec. 20 and 23.What's the difference ... As the Earth travels around the sun, it does so at ...

The winter solstice falls between Dec. 20 and ... For most of the year, the Earth’s axis is tilted either toward or away from the sun. That means the sun’s warmth and light fall unequally ...

Spring officially begins in the Northern Hemisphere on March 20 with the vernal equinox as the entire world experiences an ...