What is a galaxy? All you need to know about galaxies

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!

1st eclipse season of 2024 starts March 24-25

There are many cycles in the heavens. We're coming up to a noticeable cycle, the 1st eclipse season this year. It starts with a penumbral lunar eclipse.

March equinox 2024: All you need to know

Happy equinox! The 2024 March equinox falls March 20 at 3:06 UTC. So many parts of the world will see the equinox arrive on March 19. All you need to know here.

Equinox sun above horizon all day at the poles

We know the equinox sun rises due east and sets due west. But what happens at Earth's poles? Does the sun look exactly the same at both poles?

On the equinox, are day and night equal?

Day and night are mostly equal on the equinox. There's a bit more daylight because the sun is a disk, not a point, and Earth’s atmosphere refracts sunlight.

Equinox fun: Track sun’s shift between now and the solstice

On this equinox, start tracking the sunset point on your western horizon. You'll see a mighty shift between now and the June solstice.

Year’s fastest sunsets happen around equinoxes

The year's fastest sunsets are at the equinoxes, and the slowest are at the solstices. We're talking about how long it takes the sun to sink below the horizon.

Supermoons galore in 2024!

What is a supermoon? In 2024, there are 5 new supermoons in a row from January to May, and 4 full supermoons in a row from August to November.

What’s a constellation? What’s an asterism?

Constellations and asterisms are patterns of stars. Some asterisms consist of stars from different constellations, and some are part of one constellation.

How to know your eclipse glasses are safe

Unscrupulous companies are printing ISO certification labels on fake eclipse glasses. Check here for reputable vendors from the American Astronomical Society.

2024 EarthSky Fundraiser

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