Friday, May 30, 2008

Clear Skies in the High Desert...

I was up at 3:30 this morning, and by 4 I was out walking our dogs. There was just a hint of dawn in the northeastern sky, and there was a bright quarter-moon 20° or so up in the eastern sky. As my eyes accommodated to the darkness, the familiar constellations popped out. A little while later, the Milky Way emerged from the darkness, stretching from the northern horizon to straight over head and down to the southern horizon – truly a glorious sight to behold.

The fact that I can see such things, as insignificant as it might sound, is one of my favorite things about living where we do. We're on the western slope of the mountain range that traverses San Diego County from north to south. Our house is on a north-facing slope, at about 2300 feet in altitude. In drought years, as we've experienced now for about eight years, you could call us the high desert, or at least the “near-desert”. But even in normal rainfall years, we have many days each year of extraordinarily low relative humidity – below 10% commonly, and sometimes below 5%. These conditions lead to low amounts of both water droplets and particulates in the atmosphere in our area, and that leads to amazing visibility.

Like seeing a bright moon, a looming dawn, and the Milky Way all at the same time...