Autumnal Equinox????

[Nicos]

OK- so now I'm confused!!!!

I always thought the Equinoxes were the 21st of December,March,June and September...and so today would be the Autumn Equinox?
...so what's this about then???....

BBC - Wiltshire Weather - The Autumnal Equinox - the end of summer

[HeyWayne]

I'm morer confused, I always thought equinox was an educational programme on the telebox...

[Glutton4...]

That's a no-longer updated page from about 2002! Don't the Equinoxes vary by a few days according to the moon cycle?

Just a guess - ain't got a clue really, just tryin to sound clever LOL

[Nicos]

I love your attention to detail Glutton!

Suppose, being logical, it must be something to do with the rotation of the Earth?

I know there are other Star Ggazers out there who can explain it simply????....

[piskieinboots]

I always thought it was on 21st of each - we never stop learning do we!

Is there a full point in the brain I wonder? Maybe don't answer that, just leave me happy in my little world, the sky is a nice colour

[zazen999]

Equinox - Wikipedia, the free encyclopedia

It is indeed today......

[Capsid]

The equinoxes occur twice a year when the length of the day and night are equal (hence equi = equal and nox = night). It happens when the tilt of the earth is niether inclined to or away from the sun. On December 21st is the shortest day or longest night when the northern hemisphere is tilted away from the sun. On June 21st the northern hemisphere is tilted towards the sun and we get the longest day.

[HeyWayne]

Still doesn't explain where my programme's gone...

[zazen999]

Still doesn't explain where my programme's gone...

Equinox programme guide - Equinox, Channel 4's premier science show in the UK

[bluemoon]

Basically, the Earth doesn't just spin on its axis and revolve around the sun, but it also wobbles a bit as well (bit like a spinning top that's slowing down, but not as extreme) the three things in combination can throw the timings off by a day or two. Only Spring and Autumn are equinoxes (meaning equal night), Summer and Winter are solstices.

[Nicos]

Ah ha!!..understand now- ta!!

...and so...what time is sunrise and sunset today then?( UK that is?)...I imagine that too varies with longitude!

[Capsid]

The sunset and sunrise times vary depending on where you are in the UK. The times vary according to latitude (how far from north or south you are) not longitude (although there are local time zone differences). In the arctic summer the sun never sets and never rises in the winter.

http://www.schoolsobservatory.org.uk/cgi-bin/srs_uk.cgi

[piskieinboots]

and the difference between equinoxes and soltices is (for those of us that don't know, I didn't):

The solstices are defined as the times at which the sun is furthest from the celestial equator, and hence the difference in length between night and day is greatest. The winter and summer solstices usually occur around the 21st December and 21st June respectively, but are subject to change due to the earth's orbit being slightly longer than our 365 day calendar.

The equinoxes are the times at which the sun is closest to the celestial equator, resulting in day and night being of almost equal duration. They occur around the 20th March (the vernal equinox) and the 22nd September (the autumnal equinox), though are subject to variation for the reasons stated above.

[HayleyB]

Well there you go then another puzzle solved

[Snadger]

Did I miss summat?