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Posts by
Editors of EarthSky
Solstices and equinoxes in a video from space
See how sunlight falls on Earth's surface during the solstices and equinoxes, and get a better understanding of why Earth's tilt causes the seasons.
December 21, 2023
Orion the Hunter and the Milky Way on December evenings
The constellation Orion the Hunter is very easy to find. If you have a dark sky, you can also see the luminous band of the Milky Way running behind it.
December 17, 2023
The Wright brothers succeeded 120 years ago
Check out one of the world's most famous photos. It shows the Wright brothers and the 1st true airplane flight on December 17, 1903.
December 17, 2023
What’s a green flash and how can I see one?
Have you ever seen the green flash from a setting sun? Learn how to see one here, plus how they appear, and enjoy some great photos and watch a video!
December 7, 2023
Kelvin-Helmholtz clouds look like ocean waves
Kelvin-Helmholtz clouds - aka billow clouds or shear-gravity clouds - can sometimes look like ocean waves. Check out these photos of them!
December 3, 2023
EarthSky’s lunar calendar: How to use this great gift!
Follow the moon! Here’s why you need an EarthSky lunar calendar, the top tips for using it, and where you can order one.
December 1, 2023
December birthstone: turquoise, zircon or tanzanite
The December birthstone is 1 of 3 gemstones, the exquisite blue-green turquoise, dazzling zircon, or the magnificent blue-violet tanzanite. Your choice!
December 1, 2023
Achernar is the End of the River of Eridanus constellation
Achernar is the 9th brightest star and flattest star known. It marks the end of Eridanus the River. Here's why much of Earth never sees it ... and how you can.
November 22, 2023
Meet Hamal, an ancient equinox star
Meet Hamal, the brightest star in Aries, and learn why people sometimes refer to the March equinox point as the First Point in Aries.
November 19, 2023
Almach, a quadruple star system in Andromeda
With the eye alone, Almach looks like a single star. Through a telescope, it looks like a colorful duo. But Almach is really 4 stars.
November 17, 2023
