Where’s the normal matter in our universe?

Planets and stars in the night sky are made of normal matter. Yet only 9% of the universe's normal matter is in objects such as these. Where is the rest of it?

Sumatran tiger sightings triple on Indonesian island

Camera traps on the Indonesia island of Sumatra caught 3 times as many endangered Sumatran tigers as before. The Sumatran tiger is thriving in this region.

The last full supermoon of 2025. Best pics here!

The full Cold Moon on December 4 was the last supermoon of 2025. See a gallery of photos of the last full supermoon from the EarthSky community here.

Will we digitize human bodies for healthcare?

What would it be like if we could digitize human bodies? We could recognize heart attacks as they happen and deliver tailored doses of medicine to the sick.

See the best deep-sky photos of November 2025 here

Enjoy this gallery of deep-sky photos for November 2025 from our EarthSky community. If you have a great photo to share, send it in, too. We love to see them!

What time is it on Mars? The 1st precise answer

What time is it on Mars? The time difference between Mars and Earth is a complicated puzzle. But it's necessary to solve for future explorations.

Audubon Christmas Bird Count signup has begun

The Audubon Christmas Bird Count, held each winter, is one of the longest-running community science projects. You can help collect important data about birds.

December birthstone: turquoise, zircon or tanzanite

The December birthstone is 1 of 3 gemstones, the exquisite blue-green turquoise, dazzling zircon, or the magnificent blue-violet tanzanite. Your choice!

Andromeda Galaxy: Find it by star-hopping from Pegasus

The 4 stars of the Great Square of Pegasus are easy to find. Ready? Let's star-hop! Use these guide stars to help find the Andromeda galaxy.

Proximity to a supermassive black hole doesn’t spell doom

Scientists found that stars in the "S-cluster," a group of young, high-velocity stars orbiting our galaxy's central supermassive black hole, have stable orbits.