In our picture of the dawn scene on January 5,
you can see the ball of our planet (the great black curve of the horizon in the foreground) and the globe of the Sun about to rise into view; and these two globes – the nearby apparently huge one, and the distant really huge one – are about at their closest to each other in space.
That is, the Earth is at perihelion, the inner point of its slightly elliptical orbit, on Jan. 4 (at 17 Universal time).
Yet we’re in the depth of winter. The relatively slight difference in distance from the Sun is not the cause of our seasons. The cause is our planet’s tilted attitude as it orbits around the Sun: north hemisphere leaning most toward the Sun at the June solstice, most away from the Sun at the December solstice. So Dec. 21 was (for our northern hemisphere) the date of shortest and lowest daylight.
But, because of other factors that we explain here, the earliest sunset occurred back on Dec. 7, and the latest sunrise comes now, on Jan. 5. (The dates vary somewhat with different latitudes.) Dec. 7 seemed the shortest day if you were watching and timing (very carefully!) the sunsets, Jan. 5 will seem the shortest if you are watching the sunrises.
Those are two of the signposts of midwinter. We are on the slope back toward summer in that daytime is beginning to get longer at both ends.
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Our sunrise here on Cape Cod is today, at 7:13 AM. That’s where it’s been for seven days; that’s where it’ll be for another seven days before it starts to retreat.
So close to the solstice, we (indeed, we all) are on the flat part of the daylight sine curve’s roller coaster. It will be steepest come the equinox.
Trigger warning before you read on Guy …
The latest sunrise here on Cape Cod is not today.
It was last November 5th at 7:22 AM ,
the Saturday morning before converting from Daylight to Standard Time !
We have to keep this to Stanrd Time, othewise it would become horribly more confusing.
Relevant times for Sydney today (5 January):
Sunset 20:09
Civil twilight ends 20:38
Nautical twilight ends 21:14
Astronomical twilight ends 21:52
Sydney (-33.8), Adelaide (-34.9) and Auckland (-36.9) are all at reasonably similar latitudes.
Guessing at Sydney’s latitude, assuming it’s the one in Australia and not the Canadian one(Nova Scotia I think?),that it’s not quite properly dark by 21hr..I was in Auckland, New Zealand about 5 years ago and thought I’d nip out to the Dominian Park to reacquaint myself with the southern stars which I hadn’t seen for a few years.I got up at about 20hr after sleeping off the long flight from Europe and it was still light!I think Auckland is roughly the same latitude as Adelaide?
Latest sunset of the year here in Sydney in a couple of days’ time (7 January).
I think of the weeks between earliest sunset (December 6 here at 38 degrees north latitude) and latest sunrise (January 5) as the yuletide, a time to rest, savor the long dark nights, and not overdo anything during the short hours of daylight. My energy starts to increase once the days start getting noticeably longer later in January.
My latest sunrise was on the 3rd at 0827 as of today (4th)the daylight is now expanding both ends.As I recall my earliest sunset was way back on the 19th of December at 1538 but we have an extra 12 minutes of daylight as of the 4th already.In fact I spotted Venus in the sunset tonight and the first time I’d seen it in 2023.I normally use my Helios Starfield wide field 2×40 binoculars for such Venus and Mercury sweeping but I only had my Zeiss Mini Quick 5×10 monocular on me and still managed to nab Venus despite the fairly narrow field of view.4 planets under the belt in 2023, Jupiter, Mars, Venus and……. Earth!