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Editors of EarthSky

Visible planet night sky guide Pending

Visible planets: Morning: Mercury, Mars and Saturn. Where are Jupiter and Venus? They are too close to the sun to see this month.

What’s a galaxy? All you need to know

What is a galaxy? We live in a galaxy called the Milky Way. But there is so much more to know about these grand and glorious star islands in space!

Constellations and signs: What’s the difference?

What is the difference between signs of the zodiac and constellations of the zodiac? Astronomer Guy Ottewell illustrates and discusses this difference.

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.

Auroras on May 10-11 wowed millions! Pics here

Auroras last night from "extreme" geomagnetic storming - which came after a week of very high activity on the sun - wowed millions around the globe.

Which Milky Way spiral arm is ours?

Where do we live in the Milky Way galaxy? We lie between the major arms in a smaller spiral arm known as the Orion Arm. See diagrams here.

Retrograde motion can be real or illusory

Retrograde motion of planets like Jupiter or Mars in our sky is an illusion, a trick of perspective. But there's a real retrograde motion, too.

Meteor shower guide 2024: Up next the Arietids

The daytime Arietids meteor shower will be best before dawn on June 7. You'll have dark skies to watch the Arietids. Your 2024 meteor shower guide here.

Von Kármán vortices are beautiful, swirling clouds

Learn more about beautiful von Kármán vortices, a swirling pattern of clouds seen in satellite images. They occur when flowing fluid is disturbed by an object.

Mercury farthest from the sunrise on May 9

Mercury reaches its greatest elongation - greatest distance from the sunrise - on May 9, 2024. Look east at dawn. It'll brighten for the next few weeks.