The Universe

The quirks of light moving through gas are the cause of stellar twinkling, which can be a bane—and sometimes a boon—for astronomers

Galaxies come in many shapes and sizes, and trying to define them is difficult

Stars like the sun might erupt with extreme explosions about once per century

It seems contrary to common knowledge, but sound can travel through some parts of space quite well

ORCs—odd radio circles—are one of the weirdest recent discoveries in the heavens above

At the lower end, and to the bitter end, defining a star is tougher than you might expect

According to new simulations, many, even most, planets get ejected from their star early in their history

Evidence of alien worlds goes back farther than you think

Defining the word “moon” is harder than you might think

In colorful photographs of galaxies, stars, planets, and more, what you see isn’t necessarily what you get

The March 13–14 lunar eclipse will be an all-night affair you won’t want to miss

The question of whether aliens can detect our modern civilization depends on what signs they’re looking for—and, crucially, their distance from us