New research provides some clues about our solar system's most mysterious planet.
Life needs a stable climate.
It turns out proximity is pretty inconsequential.
Another day, another hypothetical object on the outskirts of the solar system.
You don't need a rocket to leave Earth. There's a slower, gentler trip in the works—and it comes with a cocktail.
This puts things into perspective
Orbits are getting a bit less mysterious.
It's both chance and certainty. And there's something kind of beautiful about that.
Something's got the Kuiper belt's rocks off, and there's a scramble to find it.
Not just a pretty planet
Approximately 100 million years before Beyonce was born
Scientists are hot on the trail of our solar system's 9th planet
From the Popular Science archives.
Is there a planet—or even planets—waiting to be discovered out there?
How skeptical should we be, and how will we find out if this mystery planet is really out there?
Sudden peeing, sweat balls, and so much more
There's a good reason why all of today's manned spacecraft look pretty much the same
It was warm and wet right around the time life got its start on Earth.
And that's only the inner asteroid belt.
Happy Carl Sagan day! Celebrate with this blast from the past in the pages of Popular Science
Figuring out the daily grind