Chaco Culture National Park and the Aztec Ruins National Monument on Saturday hosted winter solstice events on Dec. 21, the shortest day of the year.

Chaco opened to the first 100 visitors to arrive about 6:30 a.m. Saturday for the 7:19 a.m. sunrise. Aztec Ruins opened at 4:30 p.m. for the 4:59 p.m. sunset, which aligned with the back wall of the Aztec West Great House.

The winter solstice occurs twice a year in the northern and southern hemispheres. In the north, on Dec. 21 or 22, the solstice has the shortest day and longest night, when the sun is at its lowest elevation in the sky.

In the southern hemisphere, the winter solstice occurs on June 21 or 22.