Over the last several years or so you may have heard your local TV weather person declare March 1 as the start of meteorological spring.

It's certainly not a light switch, though. Some of the worst winter storms can raise havoc in March and even early April.

The reason meteorological spring occurs on March 1 is mainly for record keeping.

According to the National Centers for Environmental Information, a branch of the National Oceanic Atmospheric Administration, the 12 months of the year are divided into four seasons, each with three months. A few weeks back we finished metrological winter that runs from Dec. 1 to Feb. 28 (or Feb. 29 every four years). Meteorological spring continues through May 31.

I can certainly understand how defining seasons in this way makes it a lot easier for record keeping, but I still prefer the traditional astronomical start to spring, the Vernal Equinox.

That's a bigger deal, as far as I'm concerned, because that's when the sun crosses the celestial equator and heads into the northern half of the celestial sphere.

Astronomical seasons are due to the fact that as Earth revolves around the sun its axis is tilted by 23.5 degrees to its orbit around our home star. Because of that, the Sun's path among the backdrop of stars, known as the ecliptic, is inclined to the celestial equator by that same 23.5 degrees.

The celestial equator is just a projection in our sky of the Earth's terrestrial equator and occupies the same mathematical plane as Earth's terrestrial equator. Because of where we live the celestial equator runs from the eastern to western horizon, and its highest point is due south about halfway from the horizon to the overhead zenith.

At 12:15 p.m. Tuesday the sun will be smack dab on the celestial equator in our sky. That means the sun is shining directly overhead anywhere along Earth's equator. This also occurs in late September on the day of the Autumnal Equinox. All parts of Earth experience equal amounts of sunlight and radiation on both Vernal and Autumnal Equinox days.

On Summer Solstice day in late June the sun's most direct rays shine over the Earth's northern hemisphere. That puts the sun high in our sky at its maximum separation north of the celestial equator, making our days much longer than our nights.

On Winter Solstice day in late December the sun's most direct rays are shining over the Earth's southern hemisphere. That puts the sun very low in our sky at its maximum separation south of the celestial equator, making our nights longer than our days.

There's a good chance this Tuesday that if you surf news channels or programs on your cable or satellite system you're bound to see a weatherman or an news anchor attempt to balance an egg on its end.

If and when they finally get that egg to stand up on its own they'll claim that it's because of the Vernal Equinox.

That's absolute malarkey.

The truth of the matter is that you have just as much of a chance to get an egg to stand up vertically on any other day of the year. The equinox has absolute nothing to do with it. Try this on your own at another time of the year, if you have a lot of extra time on your hands and a lot of patience.You've also been told over the years that on Vernal Equinox day everyone worldwide has equal amounts of daylight and nighttime. That's yet another myth.Certainly it's true about both hemispheres receiving equal sunlight, but actually the days become longer than the nights. Just check the almanac data in the Eagle you'll see that we exceed 12 hours of daylight on St. Patrick's Day.Earth's atmosphere is responsible for this. The sun's light, coming from 93 million miles away, is bent by the shell of our atmosphere, something called astronomical refraction. The thicker the atmosphere, the more the sun's light is bent.Whenever the sun is rising or setting any time of year, its light has to cut through a lot more of the atmospheric shell than it does when the sun is overhead. The bending of the sunlight is so extreme at the horizon that the sun's disk will appear above the horizon when it's actually below it, giving us extra daylight.Believe it or not, up until about 1750 New Year's Day was not celebrated on Jan. 1 in England and early America. They brought in the New Year on the first day of spring because shortly after that day it begins to green up, and nature begins anew. England and the colonies were still operating under an old calendar with roots that dated back to Babylonian times.Most of the western world, especially Roman Catholic countries, switched over to the Gregorian calendar back in the late 1500s.That calendar had Jan 1 as the first day of the year. England finally decided in 1750 that it was time to get in sync with the rest of the western world and adapted the Gregorian calendar.Happy spring. Eat your eggs, but forget balancing them. It could get a little messy if they roll off the table.Celestial hugging this weekThe planets Venus and Mercury are in a tight celestial hug in the very low western sky during evening twilight. Venus is by far the brighter of the two.The new crescent moon will join them early Monday evening and will be parked just above the planets Tuesday evening.Look for them as soon as you can after sunset because they'll all be setting shorting after twilight ends.Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is also the author of “Stars: a Month by Month Tour of the Constellations,” published by Adventure Publications and available at bookstores and at adventurepublications.net. Contact Mike Lynch at mikewlynch@comcast.net.