Even in space, bureaucracy exists.
We're under a time crunch.
It defied the odds to discover thousands of planets.
And it could help prove the existence of Planet Nine.
It could be the largest moon we've ever seen
From the Popular Science archives.
Is there a planet—or even planets—waiting to be discovered out there?
The early solar system was a wild, world-destroying place.
It's time to return to our hellish neighbor.
Another day, another hypothetical object on the outskirts of the solar system.
It's surprisingly lacking in heavy elements
Scientists aren't just jerking you around—this is about something more than your childhood nostalgia
New evidence suggests it could be a rogue planet captured by our sun
Naming new worlds is a confusing mess
This summer we'll get our closest ever look at the stormiest planet in the solar system
How skeptical should we be, and how will we find out if this mystery planet is really out there?
Scientists are hot on the trail of our solar system's 9th planet
Short answer: It depends who you ask
Pluto is just the beginning
New Horizons scientist Leslie Young discusses what to expect from the flyby on Tuesday, and the 28-year wait leading up to it
This year's missions to the outer solar system are set to shake up the planetary family tree
The finding is good news for the search for intelligent alien life
The Dawn spacecraft arrives at Ceres this March, and it could be the most surprising space mission in decades