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That's hard to say aloud! "Solstice subSun... Solstice subSun... Slawsys subSin..."

The "winter" solstice occurred last evening (evening here in my longitude) at 10:27:24pm Eastern US time (EST) which was 03:27:24 UT. That time is correct to within a couple of seconds, I believe. By definition, this is the event when the Sun for a geocentric observer (or is it Earth-Moon barycentric?) reaches an SHA of exactly 90.0°. Of course it's generally defined in the terminology of astronomers, not navigators, so it's safer to say that this occurs when the right ascension, RA, of the Sun reaches 270°, often written as 18:00 hours in astronomy (same angle, different tradition being called out).

Winter here is summer down there in that other hemisphere. And that's where the solstice happened... high in the sky above the Australian desert.

The solstice traditionally marks the beginning of winter in the northern hemisphere, but that's really just a bit of astrology that has made its way into our civil calendar, especially in the USA. It's the instant that the Sun enters the astrological sign of Capricorn (note: that this is distinct from the constellation). The date has no particular weather significance. Nor does it have much astronomical significance. Today is actually the beginning of increasing sunlight with each passing day, so by rational astronomical rules (as if!), this ought to be the middle of winter, the low point in the Sun's illumination. By average weather, since the weather lags the sunlight, the coldest quarter of the year --winter by the weather-- started near the beginning of December and will bottom out in about a month. We're already deep in it.

But that also means that the coldest quarter ends sooner than we expect from the civil calendar. You don't have to wait until March 20 (-ish) to celebrate the arrival of Spring. By weather that starts around March 1 ...and that's just right around the corner, no matter what that Punxsatawney Peabrain says on February 2nd. Of course deep in the southern hemisphere, this solstice is the day when the Sun is baking the Earth down there, as far south as it can get. And at the exact instant of the solstice at 10:27:24 (tonight EST), the Sun will be directly above one of the most barren spots in the world in west-central Australia, hundreds of miles from the nearest paved road, about 625km nearly due west of Alice Springs, Australia. It's like the surface of Mars down there with the heat turned up to Venus levels. The images attached show a wide view, then a zoom in, another zoom, and one more zoom. It's all the same!

Frank Reed

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