Daily cosmobite: Midsummer Day

22_Sunset_Nick LombToday is the day of the summer solstice for at 4:11 am Australian Eastern summer time the Sun reached its most southerly position for the year. At midday (~1 pm summer time) it is at its highest in the sky for the year and the interval between sunrise and set is the year’s longest.

A sunset. Photo Nick Lomb

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6 responses to “Daily cosmobite: Midsummer Day

  • hello.
    i live in newcastle and noticed the latest the sun sets in summer is 8.05 pm. i remember when i was young noticing seeing that the sun set at 8.10 pm. could that be right or is it always 8.05 pm?
    cheers.
    rob

    • Hell Rob. The latest sunset in January from Newcastle NSW is 8:05 pm AEDT, as you indicate. That time would not change by more than a minute from year to year. The 8:10 pm time you recall is the latest sunset time from Sydney; maybe when you were young only the Sydney times of sunrise and sunset were quoted in the Newcastle papers as calculating these times was highly time consuming in the days before electronic computers.

  • Hello Nick

    Would like to ask a question regarding the direction of Sun rise and set during Summer here in Perth. W.A.

    I have been taking compass bearings of the direction the Sun has been rising and setting during Dec here in Perth.

    I have found that the Sun is rising in the South East and sets in the South West.

    I would have expected that the Sun would rise in the North East and set in the North West. Obviously my reasoning is flawed and I was hoping you could explain why.

    My reasoning is that the furthest South the Sun gets is 23.5 degrees latitude on the Summer Solstice (22 Dec 13). As Perth’s latitude is nearly 32 degrees it would mean that the Sun is to the North of Perth and because of this I would have expected that the sun would rise to the North of East and set to the North of West.

    Thanks for considering this question.

    Regards

    Jim

    • Hello Jim. This is a good question that I will answer in more detail in a blog post on the Sydney Observatory blog in a week or two. In the meantime I will try to give a brief explanation without a diagram. During a day the Sun moves in an arc that is always tilted at 32° (Perth’s latitude) to the vertical and with the highest point towards the north. At the March and September equinoxes the Sun rises in the east, moves toward the north and sets in the west. At the June (winter) solstice the Sun rises north of east, makes a small circle towards the north and sets north of west. At the December (summer) solstice it rises south of east, makes a large circle with its highest point still a little north of being overhead and sets south of east.

      I hope that that explanation helps but as I said above in a week or two I will try to provide a blog post with a diagram to try to make the Sun’s motion clearer.

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