Time and again during our Chihuahuan Desert winter holiday season, we get days when it's warm and sunny, when the hot-blooded can comfortably go about in shirt sleeves. For the rest of us, a light jacket is plenty as we bask in the winter sun. Like so many things in this universe, though, this is subject to change.
There are many astronomical processes that affect us. One of these is
the fact that the Earth currently makes its nearest approach to the sun in early
January, just when we need it most. And to add to the blessing, we are farthest from
the sun in mid-summer, when the last thing we need is more heat. But stick around—this
won't last! Slowly the time of closest approach will creep through the months, and
by 11,000 years from now, all will be reversed. January will see the sun several
million miles farther away, and July several million miles closer. Patience will pay
off though—in January a mere 22,000 years from now, we'll welcome back our beloved
desert sun.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.