Stories by Phil Plait

The collision of supermassive black holes shakes the entire cosmos, hard

You might think galaxies can’t ever find each other in our runaway cosmos, but it turns out gravity can sometimes overcome even the stretching of space itself

The venerable Hubble observatory is going strong despite its decades in space and the advent of next-generation successors

From planet-scorching stellar outbursts to cataclysms so powerful they shiver the very fabric of spacetime, these are some of the biggest blasts our cosmos has to offer

Stars emit lots of green light, but our eyes don’t let us see them that way

Total eclipses, lunar occultations, planetary conjunctions and meteor showers await stargazers this year

The “Seven Sisters” of the Pleiades are part of a much larger complex that can help reveal our galaxy’s deep history

Record-breaking objects can tell us about the most powerful events in the cosmos—sometimes

Depending on how you look at it, this catchphrase from a 1980s pop song is decently accurate: you can actually melt the planet if you stop its turning

Precisely calibrating clocks on Mars is harder than you’d think, because of some extremely esoteric physics

In our topsy-turvy universe, sometimes the farther away an object is, the bigger it seems to be

A technique called interferometry can greatly magnify tiny objects on the sky, and is powerful enough to reveal the surfaces of nearby stars

Comets don’t just orbit our sun. “Exocomets” are common around other stars in the galaxy, too

Centuries before other galaxies were known to exist, astronomers called them “spiral nebulas.” Today the defunct term still sparks confusion

Observations show the disk of our galaxy is not flat but warped and waving. Astronomers are still working out the reasons why

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?