Blog
Writing on astronomy, photography, and the science of the sky.
Does the Sun Rise in the East? Only Twice a Year
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.
Golden Hour and Blue Hour: How Long They Actually Last
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.
The Shortest Day of the Year (and Why Your Earliest Sunset Already Happened)
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.
What is the Summer Solstice and When Is It?
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.
Astronomical Definitions: A Comprehensive Guide
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.
How Long After Sunset Does It Get Dark?
About 70 minutes near the equator, over two hours farther north, and never in London in June. Twilight times by latitude and season, and why the 30-minute rule breaks.
How Elevation Affects Sunset and Dusk Times
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.
Why Watching the Sunset Makes You Happier (The Science of Light)
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.
Sunset vs Dusk: The Difference, and Which Is Worth Staying For
Sunset is the instant the sun disappears. Dusk is the end of twilight, and there are three of them. How far apart they fall by latitude, and which view is worth waiting out.
How is Sunrise Calculated? (Refraction, Algorithms, and Math)
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.
Does Air Pollution Actually Make Sunsets Better?
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.
Sunsets are Better in the Winter: Here's Why
Cold air holds up to 15 times less water vapor than summer air, and water vapor is what turns clean color into haze. The real reasons winter sunsets look better.
Are Sunsets the Same Everywhere?
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.
Can There Be a Beautiful Sunset Without Clouds?
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.
