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Editors of EarthSky

Astronomy Essentials

See Venus in the daytime: Here are 3 helpful tips

You can spot Venus in the daytime. One of the best ways is when its near the moon. Here are 3 tips to help you spot the brilliant planet Venus in daylight.

Crepuscular rays are sunrays in twilight skies

Crepuscular rays form around twilight when particles in the atmosphere reflect the sun's light beams toward our eyes. See photos of the phenomenon here.

What is retrograde motion? And why is the moon moving backwards?

What is retrograde motion? See an image that appears to show the moon moving backwards! An explanation, and more bizarre examples, here.

How many stars can you see on a moonless night?

Have you ever wondered how many stars are visible on a given night? It depends on factors including how dark your sky is and what your age is.

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 for it in the north-northeast sky on September and October evenings.

Roman space telescope has launched! You can adopt a pixel

The Nancy Grace Roman Space Telescope launched on August 30 from the Kennedy Space Center. Want to add your name to a pixel? Find out how here!

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.

Do you love twilight? The 3 stages explained

Twilight is that magical time between sunlight and darkness. Astronomers, experts on nighttime, recognize 3 stages of twilight.

Best eclipse photos! Nearly total, August 27-28

EarthSky community photos of the lunar eclipse of August 27-28, 2026. Thanks to all who submitted eclipse photos!

The Winter Circle: Catch in the morning before dawn

The majestic Winter Circle isn't a constellation. This giant circle - or hexagon - is an asterism, or a pattern made up of stars from several constellations.