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Posts by
Editors of EarthSky
October birthstone: Colorful opal and tourmaline
Take your pick: the October birthstone is either the striking iridescent opal or the many-colored tourmaline. Learn the lore of these pretty gemstones here.
October 1, 2025
How many stars can you see on a moonless night?
Have you ever wondered how many stars are visible on a given night? It all depends on how dark your sky is, what your age is, and other limiting factors.
September 23, 2025
We have 4 seasons each year, but why?
Some assume our planet's changing distance from the sun causes the 4 seasons. But it's actually the tilt of the Earth's axis.
September 21, 2025
Cassiopeia the Queen ascends in September and October
Cassiopeia the Queen is an easy-to-find constellation. It has the shape of a W or M. Look in the north-northeast sky on September and October evenings.
September 11, 2025
Astronomy Essentials
Saturn’s rings: Top tips for beginners
If you want to see Saturn's rings, September 2025 is a great time to look. Grab a telescope, find a dark sky and read the tips found here!
September 7, 2025
Sapphire: September birthstone comes in many colors
Sapphire, the September birthstone, is typically blue, the color caused by small amounts of titanium and iron in the crystal structure.
September 2, 2025
Do bees die after they sting you?
Do bees die after they sting you? Only the honeybee dies after stinging you, and only female bees have stingers. The female honeybee dies protecting its home.
August 26, 2025
The Winter Circle: Catch in the morning before dawn
The majestic Winter Circle isn't a constellation. It's an asterism, a giant circle - or hexagon - figure made up of bright stars from several constellations.
August 24, 2025
The return of Sirius in the morning signals seasonal change
A sign of the changing season is the return of Sirius before sunup. Want to make sure you've spotted Sirius? The 3 stars in Orion's Belt point to it.
August 21, 2025
Do you love twilight? The 3 stages explained
Twilight is that magical time between sunlight and darkness. Astronomers, the experts on nighttime, recognize three stages of twilight.
August 15, 2025
