The Winter Solstice 2015 – long nights for winter viewing

VJM.WinterSolstice2015
Venus, Jupiter and the Moon are visible in the western sky after sunset this weekend. Here they are on Sunday evening, June 21, 2015. Chart created in Stellarium.

Has it been dark lately when you arrive home from work or school? Have you noticed the nights are long and the days are cold? Its winter solstice time again!

Solstice means “sun standstill”, but the Sun’s apparent motion doesn’t stop nor does the Earth stop turning. Since the beginning of the year (or the summer solstice to be precise) the position of sunrise (and sunset) has been shifting gradually northward along the horizon. On the solstice this northward movement ends – the Sun stands still on the horizon for a few days – and then it heads back south.

More precisely, in 2015 the southern winter solstice occurs at 02:38am AEST on Monday June 22. At this moment the Sun is at its most northerly point on its path through the sky and directly above the line of the Tropic of Cancer. While it will be dark in Australia, somewhere on the Tropic of Cancer it will be 12 noon locally and the Sun will be directly overhead. That somewhere will be in the west Atlantic ocean just north of the Dominican Republic and any yacht sailing there will cast no shadow.

Map.WintSolstice2015
The (southern) winter solstice in 2015 occurs with the Sun over the west Atlantic ocean north of the Dominican Republic. Map data ©2015 Google, Sanborn.

The solstice is a natural turning point in the year. Historically it was a time of new beginnings, of rebirth and revival. From now on the days will lengthen and the warmth of summer is on its way.

Although Monday is solstice day itself you wont notice much difference in the length of the day over the weekend. So make the most of the long nights and watch Venus, Jupiter and the Moon shining in the western evening sky.

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7 responses to “The Winter Solstice 2015 – long nights for winter viewing

  • On Winter Solstice, it should have the longest day in southern hemisphere, like in Australia, while it should have the longest night in northern hemisphere. Am I right?

    • Aries, Ideally you need to specify a hemisphere when referring to ‘Winter solstice’. Your comment is correct if you are referring to Winter Solstice…in-the-northern-hemisphere.

  • Hi Andrew, the second graphic shows WHERE the 2015 June solstice will occur in the northern hemisphere (on the tropic of Cancer). Do you have the data to tell WHERE it will occur in the southern hemisphere (on the tropic of Capricorn) ?

    • Hi Lars, This can be tricky to visualise without a model of the Earth and Sun. The (southern winter) solstice occurs at a single point in time and that time is when the Sun reaches its most northerly point on the ecliptic. At that time it will be directly above the Tropic of Cancer. Somewhere along that Tropic it will be midday locally. That is what I show in the second graphic. The Sun cannot then also be over the Tropic of Capricorn. We commonly refer to the solstice as the day on which the solstice occurs – “Monday is the solstice” – but the solstice is in fact a single, precise point in time.

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