Space
How much water on exoplanets does life need?
Astronomers think water is essential to life as we know it. So how much water on exoplanets does life need? A new study suggests 20-50% of Earth's water.
Sun
Sun news: Sun activity jumps with three M flares!
Sun news for April 23, 2026: Three M flares rocked the sun this morning! Each fired sun-stuff into space, which forecasters are now analyzing.
Astronomy Essentials
Tonight

Visible planets and night sky guide for April and May

Visible planets and night sky guide. Tomorrow, look for the half-lit 1st quarter moon. It'll rise about noon and be high in the sky at sundown.
Astronomy Essentials

Here’s how to see the Lunar X and V at 1st-quarter moon

Lunar X and Lunar V are optical features on the moon. They are visible through a telescope for several hours around the time of the 1st quarter moon.
Space

See great pics of Comet R3 PanSTARRS from our community

Comet R3 PanSTARRS is now too close to the sun to see. But enjoy these fantastic photos from the EarthSky community of when it was in the morning sky.
Earth

Lights out for birds during spring migration!

Turn the lights out for birds during spring migration. And check out the links here to maps that show when birds are passing over the area where you live.
Space

Black hole Cygnus X-1 has fast, powerful dancing jets

The Cygnus X-1 black hole emits jets that are bent by stellar winds from a companion star. This has enabled astronomers to calculate the power of those jets.
Space

Summer solstice in Mars’ southern hemisphere is April 25

The summer solstice in Mars' southern hemisphere happens on April 25, 2026. Summertime there typically kicks off dust season on the red planet.
Earth
Human World

Happy Earth Day! Why do we celebrate it on April 22?

April 22 is the date of Earth Day in part because of Arbor Day, an earlier observance. The focus for 2026 is "Our Power, Our Planet."
Space
Today's Image

Earth images from space: 10 incredible photos of our planet

Happy Earth Day! As a celebration of Earth, enjoy these photos, a collection of the 10 best Earth images from space. What are your favorites?

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