Top 6 favorite EarthSky videos from 2025. Watch them here!

Here are our top 6 favorite EarthSky videos from 2025. What will we share in 2026? Visit YouTube.com/@EarthSky to find out!

What was the Christmas star? Science and mystery

What was the Christmas star? Some scientific explanations attempt to explain the Star of Bethlehem, including a planetary conjunction, comet or supernova.

December has the longest days (wherever you live)

The longest days accompany the winter solstice. In December, a day - a whole cycle of day and night - is about half a minute longer than the average 24 hours.

Mysterious 3200 Phaethon is the Geminids’ parent object

3200 Phaethon is the weird comet-like asteroid that spawns the Geminid meteor shower. New research reveals more answers ... and questions.

Thinking of buying a telescope? Read these tips 1st

Are you thinking of buying a telescope? Here's how to know if you're ready, with tips on what 1st-time buyers should look for.

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.

A peek inside Webb’s Cosmos, in media we love

"Webb's Cosmos" is a new coffee-table book displaying some of Webb's greatest images. Learn more about the book and get a peek inside here.

What’s a red dwarf? Only the most abundant Milky Way star

A red dwarf star is the smallest and coolest type of star known. They're also extremely common, making up around 75% of the stars in the Milky Way.

What are red giants? Our sun will become one!

What are red giants? Most main-sequence stars, like our sun, will become one. Red giants swell to such a large size they can swallow their inner planets.

Open star clusters are loose groups of stars

Open star clusters are young, loosely bound gatherings of stars that may still be surrounded by the nebula - or space cloud - in which they were born.