Summit County Citizens Voice

Goodbye summer, hello autumn …

Last year’s equinox from Lake Hill, above Dillon Reservoir in Summit County, Coorado.

By Bob Berwyn

FRISCO — After a few late-summer snowfalls, there’s little doubt that change is in the air, and nothing marks that more than Saturday’s autumnal equinox, when summer turns to fall, and the nights start growing longer than the days. Technically, the equinox isn’t a day, but a single moment in time (:49 a.m.) when the sun crosses the equator, so to say, from north to south, when the Earth’s axis is tilted neither away from, nor toward the Sun. Day and night are about equal lengths in both the northern and southern hemisphere, and the sun passes directly overhead at the equator.

As Wikipedia puts it, “The equinox … is a precise moment in time which is common to all observers on Earth.”

Trace the path of the sun across the sky the next few weeks. You’ll notice that, by the middle of October, it will much farther south than it is right now, and, of course, lower in the sky. In observance of the day, the Slooh space camera will stream a free webcast of live shots of the sun from telescopes around the world.

The day of the equinox is also a good time to get a good sense of compass directions from your house or your yard, as the sun rises as close to due east as it ever will, then moving south of east the next three months until the winter solstice. For more details, check out this cool web page at Space.com.

Source:OurAmazingPlanet

Equinox 2011 — summer to fall.

The green of summer and gold of autumn meet on the equinox.

Three months ago, the northern hemisphere was at its maximum tilt toward the sun on the summer solstice.

Six months ago was the spring equinox, when the sun traced exactly the same path across the sky as it will this Saturday.

The vernal equinox marks the start of spring, but March 21, 2011 brought a delicious powder day at Monarch.

Exactly nine months ago, the sun was at the other end of its celestial journey on the winter solstice.

Reveling in snow, winter solstice 2011.

Summer solstice 2010, Loveland Pass.

Filed under: Summit County Colorado, Summit County news Tagged: | astronomy, autumn equinox 2012, Earth, Equator, Equinox, September 22 equinox, solstice, Sun