The Universe

Huge eruptions from the Milky Way’s supermassive black hole in the distant past may have sterilized much of the inner galaxy

A comet’s brightness depends on how it’s made, how and when we see it, and even a bit of unpredictable luck

Voracious supermassive black holes light up the cores of “active” galaxies across the universe. How we see them, however, is a matter of perspective

If you pick the right time, our home world and our moon could be easily visible from the Red Planet

When space itself expands, weird things can happen—like galaxies breaking the universe’s ultimate speed limit

Many asteroids are related, but their family trees can be hard to trace

Gauging the mass of a black hole is tricky, but astronomers have devised multiple methods to measure the heft of these galactic gluttons

A swarm of galaxies called the Bullet Cluster is the biggest, best natural laboratory for studying dark matter that astronomers have ever seen

Some black holes get extremely massive. Is there an upper limit to their growth?

Superluminal velocities are common but illusory

The 60-meter asteroid 2024 YR4 has a 4 percent chance of hitting the moon. Could such a lunar collision create a dangerous new meteor shower?

Neptune’s discovery was a race that ended not long after this magazine came to be