Winter solstice: low sun & high moon

Q: Why is the Sun is lowest in the sky on the winter solstice and why is the Full Moon highest then? Why is the Full Moon high when the Sun is low? --Eloy & Brandon Marquis

Diagram of the Earth's seasons as seen from the north. Far right: Winter solstice. Courtesy of Wikipedia.

A: The winter Sun is low because the Earth is tipped away from the Sun. By the way, 'low' in the sky means 'southward' and high means northward.

Earth spins on its axis, causing day and night. Spin a globe. Notice the axis of rotation isn't straight up and down. Instead it's tipped from the vertical by about 23.5 degrees. Not much but it makes a difference. The difference between having seasons and not having seasons. Without that tilt--we would have eternal spring--dull. No summers, no winters. See graphic.

As Earth orbits the sun, it spins about a tilted axis and undergoes seasons. When the winter solstice arrives, Earth is tipped away from the Sun. So we in the Northern Hemisphere look south to see the Sun. Click HERE for figure. The Sun rides low (south) in the sky.

You've got the hard part--picturing a low winter Sun. Now it's easy to see why the Full Moon is high. Remember, Earth is between the Sun and the Moon when the Moon is full. Click for figure. Earth is tipped away from the Sun because it's the winter solstice and towards the Moon since the Moon is on the other side of Earth. And there you have it. We look north to see the Full Moon when we look south to see the Sun.

Further Reading:

USA Today, Earth's seasons graphic

(Answered Dec. 20, 2002;  updated Sep. 22, 2007)

Click for printer version.