• Watch for tonight's moon - September 20, 2012 - between two red objects in the night sky. One is a planet, Mars. The other is the red star Antares, Heart of the Scorpion in the constellation Scorpius. The name Ant-ares means rival of Mars, by the way. You'll find them in the southwest after sunset.
• Speaking of sunsets … here's a natural phenomenon you might never have imagined. That is, the sun actually sets faster around the time of an equinox. The fastest sunsets (and sunrises) occur at or near the equinoxes. What's more, the slowest sunsets (and sunrises) occur at or near the solstices.

This is true whether you live in the Northern or Southern hemisphere. And, by the way, when we say sunset here, we're talking about the actual number of minutes it takes for the body of the sun to sink below the western horizon.
• When the sun sets due west - as it does on the day of an equinox - the sun hits the horizon at the steepest possible angle, which hastens the duration of sunset. Although the sunset duration varies by latitude, the equinox sun sets in about 2 and 3/4 minutes at 40 degrees latitude (Denver, Philadelphia).
• On the solstices, the sun sets farthest north or farthest south of due west. The farther the sun sets from due west, the shallower the angle of the setting sun. That means a longer duration for sunset. At 40 degrees latitude, the solstice sun sets in roughly 3 and 1/3 minutes.

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