Astronomy, photography, and the science of the sky.
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Dusk is not the same as sunset. It comes about 20 minutes to an hour later, when the sun is 6 degrees below the horizon. The gap by city and season, and what dusk means on a sign or in a law.
The sun rises due east on about two days a year and spends the rest of the year off to one side. In New York the sunrise point swings 63 degrees along the horizon. In Fairbanks it swings 140.
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Golden hour is 40 minutes at the equator and over two hours in Stockholm in December. Blue hour is closer to ten minutes than an hour. The real numbers by latitude and season.
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The December solstice is the shortest day, but the earliest sunset comes weeks before it and the latest sunrise weeks after. How far apart they fall depends on your latitude.
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The summer solstice is the moment the sun reaches its farthest point north. Exact dates and times through 2030, how much daylight you get, and what the solstice is not.
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Plain-English definitions for sunrise, solar noon, the three twilights, dusk and dawn, moon phases, eclipses, equinoxes and solstices, with the details most guides get wrong.
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Usable light often fades 20 to 40 minutes after sunset. Full darkness takes longer. Compare twilight times by city and season, and find your local dusk time.
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Climbing higher pushes sunset later, by roughly 5 minutes at 1,000 meters. Here is the actual math, why the popular rule of thumb is wrong, and why dusk gets shorter.
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Sunset viewing does lift your mood, but not for the reasons most articles claim. Here is what the research actually shows about evening light, cortisol, and awe.
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Sunrise occurs when the sun's upper limb hits the horizon. Learn the math behind the 90.833 degree zenith angle, atmospheric refraction, and the hour angle formula.
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Common wisdom says pollution makes sunsets prettier. In most cases it does the opposite, muting the reds and oranges. Volcanic ash is the rare exception.
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Winter sunsets can look richer when clear air and high clouds let the colors through. Learn how haze, humidity, and the sun's angle affect the view.
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No. A sunset takes 2 minutes at the equator and 9 minutes in Alaska, and dry desert air produces far richer color than humid coastal air. What changes and why.
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Yes, and a cloudless sky shows you things a cloudy one hides: Earth's shadow, the Belt of Venus, the purple light, and the green flash. What to look for and when.
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