This means that its 1 p.m. position this weekend is precisely halfway between the low, anemic December Sun and the high-overhead late June Sun. Notice that's it's nicely high up: The Hudson Valley's equinoctial Sun is no slouch, and delivers a pretty strong level of solar irradiance.
Its height depends on your latitude. Anywhere you live, this weekend's 1 p.m. Sun displays its annual average elevation. At the North Pole, Saturday's Sun sits on the horizon, since from there it spends half the year permanently below the horizon. From south Florida it's high overhead this weekend: 18 degrees higher than from here. From the Equator this weekend's Sun stands straight up. Indeed, for folks in places like Quito, Ecuador, the Equinox is when the sun is highest of the year.
You won't beat drums or sacrifice a virgin. The good old days are over, and Equinox celebrations have been downsized to a handful of drummers in Woodstock's Magic Meadow.
Few people visualize the larger layout of Earth standing sideways to the Sun, and sunlight being distributed most evenly around our planet. Right now every populated region enjoys 12 hours of day and 12 of night, plus or minus a few minutes.
The Equinox is a milestone event on other planets, too, though each boasts its own alien equinoctial conditions. Start with Saturn, shining in Virgo: The ringed world happens to reach its closest and brightest to Earth of all of 2010 the very next day - this Sunday. Saturn has equinoxes every 15 years, and this has been the year, a few months ago. That's why its Equator and ring-plane are now virtually edgewise to the Sun, and to us. Use a backyard telescope with at least 30x, or go online to SLOOH.com, to see Saturn live. Those edgewise rings are a sight that no one will see again until 2024.
Mercury is the only planet that moves through space straight up and down, with no axial tilt whatsoever, so that it has a permanent Equinox! We'll soon have our best 2010 views of Mercury the final few days of March and the first week of April, low in the west after sunset.
Mars is a different story. With an axial tilt that's nearly a carbon copy of Earth's, Martian seasons match ours except for duration: They're twice as long, due to that world's larger orbit and slower motion. Like Saturn, the Martian Equinox happened just a few months ago, and that orange world's Northern Hemisphere is now experiencing late spring. We can still observe it easily as a bright-but-no-longer-brilliant star in Cancer; it has lost more than half its light since its closest approach six weeks ago.
The Equinox: a poetic time of balance everywhere. But not with eggs.